EP3714210B1 - Oven with sensor device and fan - Google Patents

Description

The invention relates to an oven, having an oven that encloses a cooking chamber, and an outer housing, a sensor device directed into the cooking chamber, which is arranged in an interior space between the oven and the outer housing, at least one sensor fan that is set up for this purpose, and the sensor device to ventilate with cooling air, wherein the sensor device has at least one arranged between the sensor element and the cooking space viewing pane. The invention can be applied particularly advantageously to baking ovens capable of pyrolysis.

In the case of sensor devices which are arranged on an oven of a baking oven, the problem typically arises that the sensor element of the sensor device is also heated when the oven is heated. As a result, the temperatures at the sensor element can rise so much that it has to be switched off to avoid overheating. This is particularly relevant when temperatures in the oven are over 300°C. In the case of self-cleaning processes in particular, the temperatures in the oven or in a cooking chamber delimited by the oven can reach over 450°C or even over 500°C.

In order to prevent the sensor element from heating up too much, a plurality of spaced discs arranged in a row between the sensor element and the oven can be provided, between which there are air cushions. This can result in the sensor device becoming large in volume, which is disadvantageous due to the cramped installation space in baking ovens. The sensor device can also be cooled by means of an air flow, which also cools the oven electronics. However, the disadvantage here is that a cooling effect has hitherto often not been sufficient.

WO 2015/185211 A2 discloses a heat treatment monitoring system comprising a heat treatment apparatus comprising a heat treatment chamber and at least one light source mount for mounting a light source for illuminating the inside of the heat treatment chamber; and a surveillance device comprising a camera, a camera light source, and a mounting portion, the mounting portion being adapted to be releasably attached to the light source mount.

EP 3 205 941 A1 discloses a heating cooker provided with: a heating chamber accommodating a food; a through hole formed in a wall surface of the heating chamber; an imaging unit that captures an image of the inside of the heating chamber through the through hole; an air blower unit that blows air outside the heating chamber; and an air-blowing duct that guides the air from the air-blowing unit. The air-blowing guide is arranged so that the air from the air-blowing unit forms an air curtain that traverses a space between the imaging unit and the through hole.

DE 197 48 002 A1 discloses a cooking appliance, in particular with means for pyrolytic cleaning, with an oven muffle, in the wall of which an oven light with a lamp holder and a lamp with a base held therein is arranged for illumination, and with a above the oven muffle between a blow-out opening of a cooling fan and an ins Free opening air outlet arranged fan shaft. In order to keep the failure rate of the lamps low, particularly during pyrolytic operation, part of the air blown out of the blow-out opening of the cooling device is directed at the lamp socket or the base of the lamp to cool it.

DE 297 18 343 U1 discloses a lighting device for a stove equipped with a fan for cooling or circulating air and a cooling air chamber that at least partially surrounds the cooking space, with a light housing to be attached in the area of a cutout in the cooking space wall, which has a socket for a lamp and the space formed by the light housing for Cooking chamber is closed by a translucent cover, wherein the lamp housing is provided with a connection for a cooling air duct, which leads at least one generated by the fan partial air flow through the lamp housing, thereby rinsing the lamp, passes.

EP 2 333 425 A1 discloses a domestic appliance for preparing food, which has a cooking chamber which is delimited by a muffle and has a fan arranged outside the cooking chamber, which is designed to generate a flow of cooling air, and includes a lamp which is arranged to illuminate the cooking chamber, and a main duct for guiding cooling air and a secondary duct for feeding cooling air are formed to the lamp, wherein an inclined deflector plate is arranged in a boundary wall of the secondary channel.

DE 10 2014 203 531 A1 discloses a cooking appliance with a cooking space that is delimited by the walls of a muffle and with an air duct device which has at least one air duct for supplying a flow of cooling air to a lighting device of the cooking appliance that is arranged to illuminate the cooking space, the air duct being arranged above the muffle and the Air ducting device has an air duct floor and an air duct cover, the lighting device having at least one light source which is arranged completely outside of the cooking chamber and around which the cooling air flow flows, which flows from an equipment compartment formed above the air duct cover into a position of a fan with respect to a flow technology; is guided in the pressure duct section of the air duct, viewed in the air duct device, the air duct device having a suction duct section that is separate from the equipment compartment and has a suction duct section that is viewed in terms of a flow-related position of the fan in the air duct device, and/or a heat sink of the lighting device is thermally coupled to the air duct base and/or the air duct cover.

DE 10 2005 044 626 A1 discloses a cooking appliance, in particular a high-level built-in cooking appliance, with at least one muffle delimiting a cooking chamber and at least one light fitted to the muffle, which has at least one lamp and a lamp cover. The lamp can be ventilated with cooling air from outside the muffle.

In EP 2 463 588 A1 an oven with an air shaft is proposed, which has a base element and a lid. The cover includes an air passage area adjoining a push-through opening for a socket of a lamp, with a plurality of ventilation openings, which allow air from a cooling air flow around the lamp to pass out of the air duct.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide improved air cooling of a sensor element of a sensor unit.

This object is solved according to the features of independent claim 1 . Advantageous embodiments are the subject matter of the dependent claims, the description and the drawings.

The object is achieved by an oven, having an oven that encloses a cooking chamber, an outer housing, a sensor device directed into the cooking chamber, which is arranged in an interior space between the oven and the outer housing, and at least one fan (hereinafter without limitation of Generally referred to as a "sensor fan"), which is set up to ventilate the sensor device with cooling air, the sensor device having a tubular sensor housing open at the end, in which at least one sensor element is accommodated and the front end of which is directed in the direction of the cooking chamber sensor device has at least one viewing pane arranged between the sensor element and the cooking chamber, a rear face of the sensor housing serves as an air inlet opening for letting in the cooling air, a pressure side of the sensor fan is air-technically connected to the rear face, the sensor housing has at least one side Has air outlet opening for discharging the cooling air and a suction side of the sensor fan is air-technically connected to a room that is separated from a room in which the sensor device is located.

This oven has the advantage that a flow of cooling air can be directed in a particularly targeted manner onto the at least one sensor element. The cooling air blown in at the front side is blown out through the at least one lateral air passage opening, as a result of which a flow rate of the cooling air flow, which flows around the at least one sensor element, is increased. In addition, the rear air intake makes it particularly easy to direct the cooling air from the separate room into the sensor housing. By conducting air from the separated space, the further advantage is made possible in terms of design that the cooling air cooling the at least one sensor element has not previously been significantly heated itself and can therefore have a particularly low temperature.

The oven can be an oven only or an oven/hob combination (stove). The oven can have one or more additional cooking functions such as a microwave function, have a steam cooking function, etc. The oven is in particular a domestic oven. The oven can also be referred to as the cooking chamber wall.

A further development is that the oven has a high-temperature cleaning function, in particular a pyrolysis function. The present invention can be used particularly advantageously since a high-temperature cleaning process results in particularly high temperatures in the cooking chamber and the at least one sensor element does not, due to the sensor ventilation, even at such elevated temperatures (which can often reach 450° C. or 500° C.). is damaged, not even during operation.

In one development, the at least one sensor element is an optical sensor element, ie it senses or senses radiation exiting the cooking chamber and passing through the at least one viewing pane. The at least one sensor element may include at least one IR sensor, e.g., at least one PIR sensor or at least one thermopile. The at least one sensor element can additionally or alternatively have at least one sensor that senses visible light, e.g. Images recorded by the camera or the camera sensor can be used, for example, to control a cooking process and/or be displayed on a screen, e.g. on a screen of the oven and/or a smartphone, etc.

The fact that the sensor housing is open at the front means in particular that it has a shape that is open on both sides at the front. The sensor housing can be covered, in particular sealed, by at least one viewing pane on the front end face facing the cooking chamber. In a further development, the sensor housing is also made of a material that is resistant to high temperatures and has poor thermal conductivity, in particular ceramic. The sensor housing can be a straight and/or a curved tube. A cross-section can be circular, oval, or angular, e.g., square.

The fact that the sensor fan is set up to ventilate the sensor device with cooling air and that a pressure side of the sensor fan is air-technically connected to the rear end face enables the sensor fan to blow cooling air into the sensor housing in a targeted manner, especially without prior cooling of other functional components of the oven.

An "air-technical connection" of areas can be understood in particular to mean that a noticeable (and e.g. not only negligibly small or not specifically generated or parasitic) air flow can be generated between these areas by means of a fan. The fact that the pressure side of the sensor fan is air-technically connected to the rear end face can include the fact that a noticeable air flow can be introduced into the rear end face from the pressure side of the sensor fan. Similarly, if a suction side of the sensor fan is air-technically connected to a room that is separated from a room in which the sensor device is located, air in the separated room can be sucked into the fan, in particular practically exclusively from the separated room .

The sensor fan may be remotely located from the tubular sensor housing and connected to the sensor housing via a hose, pipe or other air passage. Alternatively, the fan can be arranged in the area of the end face facing away from the oven.

Because the front face of the sensor housing is directed in the direction of the cooking chamber, the at least one sensor element accommodated in the sensor housing can look into the cooking chamber. In particular, a camera can be directed into the cooking chamber.

A viewing pane is understood to mean, in particular, an element that is transparent to at least one spectral range to which the at least one sensor element is sensitive. At least one viewing pane can be shaped in a beam-shaping manner, for example as a lens. At least one viewing pane may be non-beam shaping and then serve as a viewing window. The viewing pane can in particular be a pane of glass, since this is particularly temperature-resistant and practically inert to chemical environments. However, at least one viewing pane can also be made of plastic, for example if the ambient temperatures of this viewing pane do not exceed 260°C. The viewing pane(s) can, in particular, be transparent.

The sensor device can in particular have a plurality of viewing panes arranged spaced apart from one another in a row between the sensor element and the cooking chamber, as a result of which heat shielding of the at least one sensor element from the cooking chamber can be increased even further.

In one configuration, the suction side of the sensor fan is air-technically connected to an area surrounding the oven. The separated space thus corresponds to an exterior space or the area surrounding the oven. This gives the advantage that the cooling air is particularly cool.

In one configuration, the suction side of the sensor fan is connected to an air duct leading to the outside. This achieves the advantage that practically only cool ambient air is sucked into the fan.

In one configuration, the suction side of the sensor fan is connected to a separate partial area of the interior between the oven and the outer housing, which is separated from an internally ventilated area of the interior. The separated space thus corresponds to the partial area. In this way too, particularly cool air can advantageously be sucked in. This exploits the fact that an internally ventilated area typically has heat-generating components that are cooled by the internal ventilation. Using this air, which is already used to cool the heat-generating components, as cooling air for cooling the at least one sensor element would be disadvantageous since it is warmer than the air sucked in from the separated partial area or as outside air. However, in principle it is also possible to use air from an internally ventilated area of the interior for ventilating the at least one sensor element. Such heat-generating components can, for example, be electronic components, for example control electronics.

In one configuration, the sensor fan is connected to at least one heat-insulated air duct. The heat-insulated air duct can consist of a poorly heat-conducting material or be sheathed in a heat-insulating manner. This achieves the advantage that air flowing through the air duct is not noticeably heated by the area surrounding the air duct. A heat-insulating air duct can have a suction side of the fan and/or heat-insulating air duct can be connected to a pressure side of the fan.

In a further development, the sensor fan is a fan dedicated to ventilating the interior of the sensor housing, that is to say in particular it is not specifically set up or provided for cooling other heat-generating functional components. This enables a structurally particularly simple construction of the sensor ventilation. In one configuration, in addition to the sensor fan, the baking oven has a further fan (hereinafter referred to as “interior fan” without restriction of generality) for generating an inner air flow in the interior. The interior fan allows other heat-generating functional components to be specifically cooled, e.g. electronic components.

In one configuration, the oven has a fan (referred to below as a "combination fan" without restricting the generality), cooling air sucked in by the interior fan being fed into a first air stream on the pressure side (referred to below as the "sensor air stream" without restricting the generality), which is led directly to the rear face of the sensor housing, and divided into a second air flow (hereinafter referred to as "inside air flow" without loss of generality) which is led to the inner space (outside the sensor housing). In this embodiment, the combination fan thus serves both as an “interior fan” and also as a sensor fan, as a result of which a dedicated sensor fan can advantageously be saved.

In one configuration, the oven is set up to direct the internal air flow onto the sensor housing on the outside. In this way, the sensor housing can also be targeted in a cooled manner, which supports compliance with limit temperatures on the at least one sensor element.

In one configuration, the oven is set up to direct the internal air flow through a space between two viewing panes. In this way, the advantage is achieved that these viewing windows are also effectively cooled. In addition, this can prevent the air located between the viewing panes from heating up. It is a development that another space between two viewing panes is airtight is completed. A further heat-insulating layer can thus be provided between the cooking chamber and the at least one sensor element. In a further development, the airtightly sealed intermediate space is located on a side of the intermediate space through which air flows, facing away from the cooking chamber, since heat transfer to the at least one sensor element can be reduced particularly effectively in this way. It is a further development that one of the viewing panes is a viewing pane common to the airtightly sealed intermediate space and the intermediate space through which air flows, which enables a particularly compact construction. This viewing pane acts in particular as a separating pane between the two intermediate spaces.

In one configuration, the sensor housing is surrounded by at least one air baffle plate transversely to its longitudinal extent, and the oven is set up to direct the internal air flow along at least one side of the air baffle plate onto the sensor housing. The air baffle creates at least between the air baffle and the oven an intermediate space extending along the oven (hereinafter referred to as “shaft” without restricting the generality) through which the internal air flow flows. This achieves the advantage that a particularly well localized and strong internal air flow can be generated on the longitudinal section of the sensor housing onto which the internal air flow can be directed. In a further development, the at least one air baffle extends parallel to the oven.

It is a further development that there is an intermediate wall between an air baffle and the oven, with an intermediate space between the oven and the intermediate wall being filled with heat-insulating material. The duct is then formed between the airfoil and the bulkhead.

In a further development, the sensor housing is surrounded by a plurality of air baffles transversely to its longitudinal extent, which are spaced apart from one another in the direction of a longitudinal extent of the sensor housing. This results in the advantage that several, in particular parallel, shafts are provided and as a result several longitudinal sections of the sensor housing can be selectively flowed through by the internal air flow, in particular also from different directions, which facilitates the structural design of a ventilation system. The plurality of airfoils can be two, three, four or even more airfoils.

In one configuration, the internal air flow can be directed onto the sensor housing along both sides of an air baffle such that the internal air flow first flows along a side of the air baffle facing the cooking chamber and then along a side of the air baffle facing away from the cooking chamber. This results in the advantage that colder air of the internal air flow and, by dissipating heat from functional components of the oven, warmer air of the internal air flow can be directed to different longitudinal sections. In a further development, the oven is set up in such a way that the internal air flow first flows along a side of the air baffle facing the cooking chamber, then flows over at least one heat-generating functional component of the oven and then flows along a side of the air baffle facing away from the cooking chamber.

It is a further development that the colder air of the internal air flow is directed at a longitudinal section of the sensor housing arranged closer to the oven or to the cooking space than the warmer air of the internal air flow. A particularly effective cooling of the sensor housing and thus also of the at least one sensor element is achieved in this way. A further development is that the oven is set up to use a fan (e.g. a dedicated interior fan or the combination fan) to suck in the inner air flow on the side of the air baffle facing the cooking chamber and blow it out on the side of the air baffle facing away from the cooking chamber.

Another configuration is that the sensor housing is surrounded transversely to its longitudinal extension by at least one air baffle, at least one lateral air outlet opening is arranged on a side of the air baffle facing away from the cooking chamber and the at least one lateral air outlet opening is connected to an air duct which extends up to the the side of the air baffle facing the cooking chamber. This achieves the advantage that air flowing out of the air outlet openings can be fed into the internal air flow before it flows over at least some heat-generating components. This is particularly advantageous when the air flowing out of the air outlet openings is colder than the air in the internal air flow there. This can be the case, for example, if the internal air flow there has already flowed through an (internally ventilated) oven door of the baking oven. It is a development that the air duct flows into the air baffle. It is a development that the air duct protrudes through the air baffle.

In one configuration, the sensor device has at least one additional functional element in a section between the at least one sensor element and the oven. In this way, heat protection can be improved, a range of functions can be expanded and/or user-friendliness can be increased.

A further development is that at least one additional functional element is a layer of amorphous silicon dioxide, in particular aerogel. Such a layer can be arranged in particular between two viewing panes or between a viewing pane and the at least one sensor element.

A further development is that at least one viewing pane is coated, e.g. has an IR-reflecting coating. A heat transfer to the at least one sensor element can thus be further reduced.

A further development is that at least one functional element is a light polarizer or a spectral filter. In particular, at least one viewing pane can be designed as a light polarizer or spectral filter.

It is a further development that at least one viewing pane is mirrored or anti-reflective or has an at least partially reflective effect.

It is a further development that an intermediate space between two viewing panes is designed as a vacuum space, which enables particularly effective thermal insulation.

In one configuration, the sensor device is composed of a number of interchangeable modules in a modular manner. In this way, the advantage is achieved that the sensor device can be easily modified in terms of construction, for example in the factory or even at the end user, for example by a service technician. This also makes it easier to replace worn or defective components.

In one configuration, the oven is provided with heat-insulating insulation (see also above) on its side facing away from the cooking chamber, has an opening leading through the oven and the insulation, the sensor device is directed through the opening into the oven, a first (frontmost) viewing pane of the sensor device is attached to the oven, a second viewing pane of the sensor device is attached in the area of an outside of the insulation and the first viewing pane is connected to the second viewing pane via a plurality of rods. This has the advantage that heat conduction from the first viewing pane, which heats up comparatively strongly, to the second viewing pane can be significantly reduced in comparison to a tubular connection, without increasing the overall size. Only the cross-sections of the rods are available for heat flow, which can be very small compared to a tube. Hot air from the cooking chamber cannot get past the first viewing pane to the second viewing pane either, since the opening is covered by the first viewing pane. Rather, the first viewing pane, the second viewing pane and the inner wall of the insulation in the area of the opening create an air-filled chamber that provides good thermal insulation.

The rod can also be referred to as a rod or similar. The rod can be solid (voluminous) or hollow on the inside (e.g. in the form of a thin tube). It is a refinement that the rods are straight. In principle, however, they can also be curved, e.g. helically curved. In particular, there are open areas between the bars. The thermal insulation can be e.g. mineral wool, rigid foam, etc. The heat-insulating insulation is in particular arranged in layers on the oven and surrounds the oven in particular over a large area. The opening leading through the oven and the insulation is in particular cylindrical. The fact that the at least one sensor element is directed through the opening into the oven includes, in particular, that the oven is in the field of view of the sensor element.

The fact that the first viewing pane is attached to the oven includes, in particular, that the first viewing pane—if it is equipped with a holder, via its holder—is attached to the oven. In particular, it is attached to the oven in an airtight manner in order to prevent parasitic air flows from the oven past the first viewing pane or its holder. The first viewing pane thus closes the opening against the furnace chamber in an airtight manner.

The fact that the second viewing pane is attached in the area of an outside of the insulation includes, in particular, that the first viewing pane—if it is equipped with a holder whose holder—rests on the insulation. In particular, it is attached to the oven in an airtight manner in order to prevent parasitic air flows from the area of the opening on the second viewing pane or its holder into a housing area outside the insulation.

In a further development, the oven has an intermediate wall surrounding the oven at least around the opening at a distance (see also above) and the insulation is present between the oven and the intermediate wall, in particular completely filling this intermediate space. In this case, the second viewing pane or its holder can be attached to the intermediate wall. This results in the advantage that the second viewing pane can be fastened particularly stably and in a precisely positioned manner.

It is a development that the rods are spaced apart. In one embodiment, the first viewing pane is connected to the second viewing pane via a plurality of rods running parallel to one another. This results in the advantage of a particularly simple and inexpensive manufacture and a particularly robust structure.

In principle, however, the rods can also cross one another, in particular be connected to one another. The multiple rods can also take on a lattice-like form.

In a further development, the rods consist of a poorly thermally conductive material, in particular with a thermal conductivity W of less than 30 W/(m*K), in particular of less than 15 W/(m*K), in particular of less than 10 W/(m·K), in particular less than 5 W/(m·K), in particular less than 3 W/(m·K), in particular less than 2 W/(m·K), in particular of less than 1 W/(m·K).

In a further development, the rods consist of a material that is resistant to high temperatures, in particular with a heat resistance of at least 300° C., in particular of at least 400°C, in particular of at least 450°C, in particular of at least 500°C.

It is an embodiment that the rods are made of ceramic. Ceramics have the advantages of high heat resistance, high chemical inertness, potentially low thermal conductivity, and high rigidity. Possible ceramics can include or consist of, for example, porous aluminum oxide, silicon nitride, zirconium oxide or silicate ceramic. However, in principle, rods made of other materials can also be used, in particular made of non-metallic material, e.g. made of plastic such as PTFE, PEEK, etc.

In one embodiment, the edge of the first viewing panel is inserted into a first annular retaining ring. This advantageously facilitates attachment of the first viewing pane. In particular, the first viewing pane can be connected to the first retaining ring in an airtight manner. It is an embodiment that the rods are attached to the first retaining ring. This results in the advantage that the rods can be arranged particularly firmly and precisely in position relative to the first viewing pane.

In one embodiment, the edge of the second viewing panel is inserted into a second annular retaining ring. This advantageously facilitates attachment of the first viewing pane. In particular, the second viewing pane can be connected to the second retaining ring in an airtight manner. It is an embodiment that the rods are attached to the second retaining ring. This results in the advantage that the rods can be arranged particularly firmly and precisely in position relative to the second viewing pane.

In one configuration, the sensor device is loosely surrounded by a sleeve inserted into the opening over the height of the insulation. The sleeve particularly reliably prevents foreign bodies (eg fibers of the insulation) from penetrating between the rods and into the intermediate space between the first viewing pane and the second viewing pane. The fact that the sensor device is loosely surrounded by the sleeve results in the advantage that heat input from the sleeve onto the sensor device can be kept low or even avoided entirely. That the sensor device is loose surrounded by the sleeve can include that the sleeve is connected only at certain points and then only slightly to the sensor device, in particular to the rods and/or the sight glass holders. The fact that the sensor device is loosely surrounded by the sleeve can also mean that the sleeve does not touch the sensor device and is therefore arranged at a distance from the sensor device.

In one embodiment, the sleeve is also made of a material that is resistant to high temperatures and has poor thermal conductivity, in particular ceramic. This reduces heat conduction from the oven or cooking chamber even further.

In one configuration, the second viewing window is arranged on the front end of the sensor housing facing the cooking chamber, a third viewing window is inserted in an interior space of the sensor housing, and the at least one sensor element is arranged in the sensor housing on a side of the third viewing window facing away from the oven . This achieves the advantage that the at least one sensor element is protected even more effectively from heat. Thus, a further air-filled, thermally insulating intermediate space is provided by the interior of the sensor housing, the second viewing pane and the third viewing pane. In particular, the second viewing window and the third viewing window tightly seal off a section of the tubular sensor housing that is delimited by them.

Fig.1

zeigt als Schnittdarstellung in Seitenansicht eine ausschnittsweise Skizze eines Backofens mit einer daran angeordneten Sensoreinrichtung gemäß einem ersten Ausführungsbeispiel;

Fig.2

zeig als Schnittdarstellung in Seitenansicht eine ausschnittsweise Skizze eines Backofens mit einer daran angeordneten Sensoreinrichtung gemäß einem ersten Ausführungsbeispiel t;

Fig.3

zeigt als Schnittdarstellung in Seitenansicht eine ausschnittsweise Skizze eines Backofens mit einer daran angeordneten Sensoreinrichtung gemäß einem ersten Ausführungsbeispiel; und

Fig.4

zeigt als Schnittdarstellung in Seitenansicht eine ausschnittsweise Skizze eines Backofens mit einer daran angeordneten Sensoreinrichtung gemäß einem ersten Ausführungsbeispiel.

The characteristics, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

Fig.1

shows a sectional side view of a partial sketch of a baking oven with a sensor device arranged thereon according to a first exemplary embodiment;

Fig.2

shows a sectional side view of a partial sketch of a baking oven with a sensor device arranged thereon according to a first exemplary embodiment;

Fig.3

shows a sectional side view of a partial sketch of a baking oven with a sensor device arranged thereon according to a first exemplary embodiment; and

Fig.4

shows a sectional side view of a partial sketch of a baking oven with a sensor device arranged thereon according to a first exemplary embodiment.

Fig.1 shows a sectional side view of a section of a pyrolysis-capable baking oven 1 with a sensor device 2 arranged on it.

The oven 1 has an oven 3 which encloses a cooking space 4 . The outside of the oven 3--that is, on its side facing away from the cooking chamber 4--is provided with a heat-insulating insulation 5 or insulating material. An opening 6 leads through the oven 3 and the insulation 5.

The sensor device 2 has a sensor element in the form of a camera 7 whose field of vision is directed through the opening 6 into the cooking chamber 4 . The camera 7 is arranged outside the oven 3 and the insulation 6 . The sensor device 2 also has several viewing panes 8, 9, 10 made of glass arranged in a row between the camera 7 and the cooking chamber 4, of which a first viewing pane 8 is attached to the oven 3 and a second viewing pane 9 in the area of an outside of the insulation 5 is attached.

The first viewing pane 8 is enclosed in an airtight manner around the edge in a first mounting ring 11 in order to hold it. The second viewing pane 9 is enclosed in an airtight manner all around the edge in a second mounting ring 12 in order to hold it. The first retaining ring 11 is fastened to the inside of the oven 3 , with the first viewing pane 8 then being able to be located in the cooking chamber 4 . The first retaining ring 11 and the first viewing pane 8 seal the opening 6 against the cooking chamber 4 .

The second retaining ring 12 is fastened to an intermediate wall 13 running at a distance from the oven 3 on the outside. The area between the oven 3 and the intermediate wall 13 is filled with the insulation 5 . The second retaining ring 12 and the second viewing pane 9 seal the mouth of the opening 6 facing away from the cooking chamber 4 away. Through the insulation 5, the first visor 8 with holder 11 and the second visor 9 with holder 12, an air-filled space 14 is formed, which provides thermal insulation between the first visor 8 and the second visor 9.

In order to keep the flow of heat between the first lens 8 with the first holder 11 on the one hand and the second lens 9 with the second holder 12 on the other hand particularly low, the first lens 8 and the second lens 9 are connected via the holders 11 and 12 by means of several rods 15 connected. The rods 15 are fastened to the holders 11 and 12 in such a way that the rods 15 run perpendicularly to the viewing panes 8 and 9 and parallel to a longitudinal extent L of the sensor device 2 . The rods 15 run parallel to one another and are arranged equidistantly on the retaining rings 11, 12 in the circumferential direction. The rods 15 here are straight rods 15 made of ceramic.

The sensor device 2 can be loosely surrounded over the height of the insulation 5 by a sleeve 16 inserted into the opening 6, as indicated here by dashed lines. The sleeve 16 is made of ceramic, for example, and separates the insulation 5 from the intermediate space 14.

The second viewing pane 9 is also arranged on an end face of a tubular sensor housing 17 of the sensor device 2 facing the oven 3 . The sensor housing 17 is aligned with its longitudinal axis along the longitudinal extent L of the sensor device 2 . In an interior space 18 of the sensor housing 17 the third viewing pane 10 is inserted in such a way that it crosses the interior space 18 . The third viewing pane 10 is inserted in the sensor housing 17 in an airtight manner. A second air-filled, heat-insulating intermediate space 19 is formed by the sensor housing 17, the second viewing pane 9 with holder 12 and the third viewing pane 10. The camera 7 is arranged in the housing 17 on a side of the third viewing pane 10 facing away from the oven 3 . The camera 7 is thermally insulated from the cooking chamber 4 by the two gaps 14 and 15 .

In order to reduce a thermal load on the camera 5 , the oven 1 also has a sensor fan 20 which is set up to blow cool air into the end face 21 of the tubular sensor housing 17 facing away from the oven 3 ("rear"). For this is the Sensor fan 20 arranged here in a tube 27 serving as an air duct. The tube 27 is connected to a rear side of the sensor housing 17 so that a pressure side of the sensor fan 20 is connected to the rear end face 21 in terms of ventilation. The other end of the tube 27 opens into an outer housing 28 of the oven 1, so that a suction side of the sensor fan 20 is air-technically connected directly to an outside space A or the environment of the oven 1. The outer space A is separated by the outer housing 28 from an inner space 32 between the outer housing 28 and the oven 3 in which the sensor device 2 is located. The pipe 27 can be made of a poorly thermally conductive material and can therefore be thermally insulated from its surroundings. Alternatively, the tube 27 can have a thermal jacket (not shown).

Cool ambient air is sucked in through the pipe 27 by means of the sensor fan 20 and blown almost completely into the interior of the sensor housing 17 as a cooling air flow S1. In order to be able to generate a particularly strong flow of cooling air S1 at the location of the camera 7 , the sensor housing 17 has a plurality of air outlet openings 22 introduced at the side of the camera 7 .

For even more effective cooling of the sensor device 2 , the sensor housing 17 can be surrounded in an airtight manner at a height between the second viewing pane 9 and the camera 7 by an air baffle 23 extending transversely to a longitudinal extension L of the sensor housing 17 . The air baffle 23 extends here at least approximately parallel to the oven 3 and to the partition 13.

The baking oven 1 has a separate interior fan 29, by means of which an interior air flow S2 is generated in the interior 32 transversely to the longitudinal extent of the sensor housing 17 in an intermediate space or shaft 30 between the air baffle 23 and the insulation 5 or the intermediate wall 13. The internal air flow S2 in the shaft 30 is directed laterally onto the sensor housing 17 so that its air flows around a lateral surface or lateral surface of the sensor housing 17 on the outside.

The sensor housing 17 has another air baffle 24 which extends transversely to a longitudinal extension L of the sensor housing 17 and is further away from the oven 3 than the air baffle 23. The air baffle 24 extends at least approximately here parallel to the air baffle 23. A further shaft 31 is thus provided between the air baffle 23 and the air baffle 24, through which the internal air flow S2 can flow. By means of the interior fan 29 , the interior air flow S2 can thereby be directed once more onto the sensor housing 17 transversely to the longitudinal extent L of the sensor housing 17 . In particular, the internal air flow S2 first flows along a side of the air baffle 23 facing the cooking chamber 4 and then along a side of the air baffle 23 facing away from the cooking chamber 4.

The internal air flow S2 flowing in the shaft 30 thus flows around a longitudinal section of the sensor housing 17 that is closer to the cooking chamber 4 than the internal air flow S2 flowing in the shaft 31 . The internal air flow S2 flowing in the shaft 30 is in particular colder than the internal air flow S2 flowing in the shaft 31 .

The sensor device 2 can have at least one additional functional element, e.g. in the form of a motor-operated, selectively opening and closing closure or screen 25. The panel 25 is arranged in the cooking chamber 4 adjacent to the first viewing pane 8 on the cooking chamber side. The screen 25 can be provided on its side facing the first viewing pane 8 with a cleaning device which contacts the first viewing pane 8 when the screen is closed or partially closed. The surface of the first viewing pane 8 on the cooking chamber side can thus be cleaned by opening and closing it repeatedly, if necessary. Instead of or in addition to the panel, there can also be a metal grid 26 on the cooking chamber side of the first viewing pane 8 .

The sensor device 2 can be assembled in a modular manner from a number of interchangeable modules. In particular, a first module M1 can have the first lens 8 with holder 11, a second module M2 can have the second lens 9 with holder 12 and/or a third module M3 can correspond to the sensor housing 17, as indicated by the dashed lines. The sensor housing 17 can itself be divided into several modules M3-1, M3-2 and M3-3 in sections along the longitudinal extension. This results in the advantage that the air baffles 23 and 24 can be clamped between these modules M3-1, M3-2 and M3-3 for tight connection to the sensor housing 17. For this purpose, the modules M3-1, M3-2 and M3-3 can have notches in the area of the air baffles 23 and 24, around the modules M3-1, M3-2 and M3-3 outside to be able to contact the air baffles 23 and 24 over the entire surface. The additional functional units or functional elements 20, 25, 26 and the tube 27 with the fan 20 can be designed as modules.

In a variant, the rods 15 can be continued further to the rear through the second holder 12, ie in a direction pointing away from the oven 3 or cooking chamber 4, and through further modules, eg also through the modules M3-1, M3 -2 and, if necessary, M3-3 (not illustrated). This results in the advantage that the rods can also serve as fixing elements and/or assembly and positioning aids for these additional modules M3-1, M3-2 and possibly M3-3.

Fig.2 shows a sectional side view of a section of a pyrolysis-capable oven 41 with a sensor device 42 arranged thereon. The oven 41 is constructed similarly to the oven 1 .

However, the sensor fan 20 is now not attached to the sensor housing 17 but removed therefrom. In order to create an air connection between the pressure side of the sensor fan 20 and the rear end face 21 , the pressure side of the sensor fan 20 is connected to the sensor housing 44 via a hose 43 . The hose 43 is slipped over a rear section of the sensor housing 17 in an airtight manner.

In addition, the sensor device 41 is not arranged here in a region of the oven 3 without insulation 5 and without an intermediate wall 13 . Furthermore, only the two viewing panes 8 and 10 are present here, which form an airtight space 45 between them. In addition, the air outlet openings 22 are now arranged further away from the cooking chamber 4 than the camera 7.

Fig.3 shows a sectional side view of a section of a pyrolysis-capable oven 51 with a sensor device 52 arranged on it. The oven 41 is constructed similarly to the oven 1, with a fan being connected to the sensor housing 17 on the outlet side via a hose 43, similar to the oven 41. However, this fan is now a combination fan 53, which draws in cool air from the exterior space A and generates or provides both the cooling air flow S1 and the interior flow S2 separately. Alternatively, the splitting into the cooling air flow S1 and the interior flow S2 also happen behind the combination fan 53 in terms of air technology, for example by providing an air flow separator or air switch (not shown).

In addition, there is a fourth viewing pane 54 which is held by a retaining ring 55 at its edge. The fourth lens 54 is arranged between the first lens 8 and the second lens 9 . The retaining ring 55 is designed in such a way that it has lateral air passage openings 56 or forms them between it and the retaining ring 12 . An intermediate space 57 between the second pane 9 and the fourth viewing pane 54 is therefore laterally permeable for the internal air flow S2. The interior air flow S2 can thus be guided through the intermediate space 57 by means of the combination fan 53 . The air passage openings 56 are here at the height of the shaft 30. The space 19 between the second viewing pane 9 and the third viewing pane 10 is still sealed airtight.

Fig.4 shows a sectional side view of a section of a pyrolysis-capable oven 61 with a sensor device 62 arranged on it. The oven 61 is constructed similarly to the oven 1, except that the lateral air outlet openings 22 are now connected on their outside to an air duct 63, which is up to to the side of the air baffle 23 facing the cooking chamber 4, i.e. into the duct 30. The air duct 63 set up here on the left is aligned in such a way that the cooling air S1 flowing out of it into the duct 30 is directed against the direction of the internal air flow S2 there . This can be implemented in particular when the pressure of the cooling air flow S1 at the outlet of the air duct 63 is noticeably higher than the pressure of the internal air flow S2 acting in the outlet. Alternatively, however, only at least one air duct 63 can be provided, which is aligned in such a way that the cooling air S1 flowing out of it into the shaft 30 is not shown directed against or in the direction of the internal air flow S2 there.

Of course, the present invention is not limited to the embodiment shown.

The gaps 14, 19 can also be evacuated.

Of course, the present invention is not limited to the embodiment shown.

Reference List

1

oven

2

sensor device

3

oven

4

cooking chamber

5

insulation

6

opening

7

camera

8th

First visor

9

Second lens

10

Third lens

11

First retaining ring

12

Second retaining ring

13

partition

14

space

15

pole

16

sleeve

17

sensor housing

18

inner space

19

space

20

sensor fan

21

face

22

air outlet opening

23

air baffle

24

air baffle

25

cover

26

metal mesh

27

pipe

28

outer casing

29

interior fan

30

shaft

31

shaft

32

inner space

41

oven

42

sensor device

43

hose

44

sensor housing

45

space

51

oven

52

sensor device

53

combination fan

54

Fourth lens

55

retaining ring

56

air vent

57

space

61

oven

62

sensor device

63

air duct

A

outdoor space

L

longitudinal extent

S1

cooling airflow

S2

indoor airflow

Claims (12)

1. Oven (1; 41; 51; 61) having

   - an oven appliance (3), which encloses a cooking compartment (4), and an outer housing (28),

   - a sensor device (2; 42; 52; 62), directed into the cooking compartment (4), which is arranged in an interior (32) between the oven appliance (3) and the outer housing (28), and

   - at least one sensor fan (20; 53) which is designed to ventilate the sensor device (2; 42; 52; 62) with cooling air (S1),

   characterised in that

   - the sensor device (2; 42; 52; 62) has a tube-shaped sensor housing (17; 44) which is open on the face side, in which at least one sensor element (7) is accommodated and the front face side of which is directed in the direction of the cooking compartment (4),

   - the sensor device (2; 42; 52; 62) has at least one window (8-10; 54) arranged between the sensor element (7) and the cooking compartment (4),

   - a rear face side (21) of the sensor housing (17; 44) is used as an air inlet opening for letting in the cooling air (S1),

   - a pressure side of the sensor fan (20; 53) is connected to the rear face side (21) for the purpose of ventilation,

   - the sensor housing (17; 44) has at least one lateral air outlet opening (22) for letting out the cooling air (S1) and

   - a suction side of the sensor fan (20; 53) is connected to a compartment (A) for the purpose of ventilation, which is separated from a compartment in which the sensor device (2; 42; 52; 62) is located.
2. Oven (1; 41; 51; 61) according to claim 1, wherein the suction side of the sensor fan (20; 53) is connected to an area (A) surrounding the oven (1; 41; 51; 61) for the purpose of ventilation.
3. Oven (1; 41; 51; 61) according to claim 1, wherein the suction side of the sensor fan is connected to a separate subregion of the interior (32) between the oven appliance (3) and the outer housing (28), which is separated from an internally ventilated region of the interior (32).
4. Oven (1; 41; 51; 61) according to one of the preceding claims, wherein the sensor fan (20; 53) is connected to at least one thermally insulated air duct (27; 43).
5. Oven (1; 41; 61) according to one of the preceding claims, wherein in addition to the sensor fan (20) the oven has an interior space fan (29) for generating an inner air flow (S2) in the interior (32).
6. Oven (51) according to one of claims 1 to 4, wherein the oven (51) has a combination fan (53), the drawn-in cooling air of which is split into a cooling air flow (S1), which is routed directly to the rear face side (21) of the sensor housing (17), and an inner air flow (S2), which is routed into the interior (32).
7. Oven (1; 41; 51; 61) according to one of claims 5 to 6, wherein the oven is designed to direct the inner air flow (S2) laterally onto the sensor housing (17; 44).
8. Oven (51) according to one of claims 6 to 7, wherein the oven is designed to route the inner air flow (S2) through an intermediate space (57) between two windows (9, 54), and another intermediate space (19) between two windows (9, 10) is sealed in an air-tight manner.
9. Oven (1; 41; 51; 61) according to one of claims 5 to 8, wherein

   - at right angles to its longitudinal extent (L) the sensor housing (17; 44) is surrounded by at least one air baffle (23, 24) and

   - the oven (1; 41; 51; 61) is designed to direct the inner air flow (S2) along both sides of at least one air baffle (23) to the sensor housing (17; 44) so that the inner air flow (S2) firstly flows along a side of the at least one air baffle (23) facing the cooking compartment (4) and then flows along a side of the air baffle (23) facing away from the cooking compartment (4).
10. Oven (61) according to one of the preceding claims, wherein

    - at right angles to its longitudinal extent (L) the sensor housing (17) is surrounded by at least one air baffle (23, 24),

    - at least one lateral air outlet opening (22) of the sensor housing (17) is arranged on a side of the at least one air baffle (23) facing away from the cooking compartment (4) and

    - the at least one lateral air outlet opening (22) is connected on its exterior to an air channel (63), which runs as far as the side of the at least one air baffle (23) facing the cooking compartment (4).
11. Oven (1; 41; 51; 61) according to one of the preceding claims, wherein the at least one sensor element is a camera (7) directed into the cooking compartment (4).
12. Oven (1; 41; 51; 61) according to one of the preceding claims, wherein the oven is an oven (1; 41; 51; 61) capable of pyrolysis.

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