CN112690642A

CN112690642A - Cooking appliance with special air supply device

Info

Publication number: CN112690642A
Application number: CN202011138595.9A
Authority: CN
Inventors: M·纳格尔; B·瓦格纳
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2019-10-23
Filing date: 2020-10-22
Publication date: 2021-04-23
Anticipated expiration: 2040-10-22
Also published as: DE102019216343A1; CN112690642B

Abstract

One aspect of the invention relates to a cooking device (1) with: a housing (2) in which a cooking chamber (8) is formed, wherein the cooking chamber (8) is defined by walls (4, 5, 6, 7) of a muffle (3) of the cooking device (1); an air supply device (12) with which fresh air can be introduced into the cooking chamber (8) during an air supply operation of the cooking appliance (1); an air-discharging device (17) which is separate from the air-supplying device (12) and by means of which the medium can be discharged from the cooking chamber (8); and a ventilator (10) with which an air flow (L) can be generated, wherein the ventilator (10) is connected to an air exhaust device (17), wherein the air supply device (10) serves as a further air exhaust device for discharging the medium (M) from the cooking chamber (8) during steam operation of the cooking appliance (1).

Description

Cooking appliance with special air supply device

Technical Field

One aspect of the present invention relates to a cooking apparatus with a housing. A cooking chamber is configured in the housing. The cooking chamber is defined by a wall of a muffle of the cooking apparatus. Furthermore, the cooking appliance has an air supply device with which fresh air can be introduced into the cooking chamber during the air supply operation of the cooking appliance. The cooking appliance also has an air discharge device, separate from the air supply device, with which the medium can be discharged from the cooking chamber. The cooking appliance furthermore has a ventilator with which an air flow can be generated. The ventilator is in flow communication with the exhaust device.

Background

Cooking devices are known from the prior art in a wide variety of designs. A cooking appliance with corresponding air supply and air discharge devices is known, for example, from EP 3029382 a 1. In this case, a special setting of the respective lines is formed in the case of different operating conditions in which the supply air should be supplied or the exhaust air from the cooking chamber should be discharged. Valves are arranged in these lines, which valves are opened or closed as required. By means of these respective very discrete valve states, i.e. closed or open, it is possible either to close both the supply and exhaust lines or to open both, or to open one of the two lines and close the other. Due to these states, the desired conditions cannot be set or are only insufficiently set inside the cooking chamber in special operating states.

Disclosure of Invention

It is therefore the object of the present invention to create a cooking appliance in which the setting of the conditions in the cooking chamber can be improved. In particular, a compact design of the cooking appliance with a reduced number of components is also to be achieved.

This object is achieved by a cooking appliance having the features of claim 1.

One aspect of the present invention relates to a cooking apparatus with a housing. A cooking chamber is configured in the housing. The cooking chamber is defined by a wall of a muffle of the cooking apparatus. The cooking appliance also has an air supply device, with which fresh air can be introduced into the cooking chamber during the air supply operation of the cooking appliance. In addition, the cooking apparatus has an air exhaust device separate from the air supply device. The medium is discharged from the cooking chamber with the exhaust device. The cooking appliance furthermore has a ventilator with which an air flow can be generated in the cooking appliance. The ventilator is connected or connected to the air outlet device in terms of flow technology. The air supply device serves as a further air discharge device for discharging the medium from the cooking chamber during steam operation of the cooking appliance. The air supply device forms an air exhaust device during steam operation. This means that the air supply device is used for supplying fresh air into the cooking chamber in different operating modes of the cooking appliance, and on the other hand, the medium can be discharged from the cooking chamber by the air supply device in an operating mode different from the air supply operating mode, i.e. in the steam operating mode. By such a diversified application of the air blowing device, conditions in the cooking chamber can be set more flexibly and as desired. In addition, a compact construction of the cooking appliance can be achieved by this design. The number of components can thereby also be kept low.

In an advantageous embodiment, it is provided that the air supply device has at least one air supply line. The supply duct ends with a first duct end at a first opening in the wall of the muffle. In addition or instead of this, the exhaust device also has at least one exhaust line. This exhaust duct ends with a first duct end at a second opening in the wall of the muffle.

In an advantageous embodiment, it is provided that the air outlet device, in particular the air outlet line, ends with a second line end on the vacuum side of the ventilator.

In an advantageous embodiment, provision is made for the first opening in the wall, at which the first end of the air supply line ends, to be arranged, viewed in the height direction of the cooking appliance, at a higher level than the second opening in the wall of the muffle, at which the first line end of the air discharge device ends. This makes it possible to improve the flow conditions for supplying fresh air into the cooking chamber by the air supply device during the air supply operation and/or for discharging the medium from the cooking chamber during the steam operation.

Preferably, in the blowing mode, the blowing device has a smaller blowing inner cross section at least one point than the smallest blowing inner cross section of the blowing device. This is a particularly advantageous embodiment. Since in particular in the blowing mode, fresh air can thereby be brought from the outside into the cooking chamber through the blowing device in a particularly advantageous manner. Since, in particular when the ventilator is activated and the medium is drawn out of the cooking chamber by the air outlet means having a thicker cross section, the inflow of fresh air into the cooking chamber can be automatically caused on the basis of such different dimensioning of the cross sections in the air supply means and the air outlet means. As a result of the extraction of the medium by the air exhaust device during the air supply operation, a correspondingly desired underpressure is generated in the cooking chamber, which underpressure is generated by the extraction of the ventilator by the air exhaust device. Due to this negative pressure in the cooking chamber, fresh air is automatically and autonomously supplied by the air supply device with a smaller cross section during air supply operation. On account of this negative pressure in the cooking chamber, this fresh air is therefore drawn in to some extent automatically by the air supply device. This is achieved particularly advantageously by different cross sections of the air supply device and the air exhaust device. The above-described advantageous embodiments relate to at least one point, in particular points measured in the air supply and air discharge. This means that the air supply device and/or the air exhaust device, respectively, do not necessarily have a corresponding defined air supply inner cross section or air exhaust inner cross section, viewed over their entire length. However, an advantageous embodiment is possible in this respect if the smaller supply air inner cross section forms at least 50%, in particular at least 60%, in particular at least 70%, in particular at least 80%, in particular at least 90%, of the length of the supply air device. This is then particularly regarded as the smallest air supply inner cross section of the air supply device over its length. In addition or instead, this point of the smallest air discharge inner cross section, at which the air discharge device is formed, extends over at least 50% of the length of the air discharge device, in particular over 60%, in particular over 70%, in particular over 80%, in particular over at least 90% of the length of the air discharge device. The point at which the supply air inner cross section, which is smaller than the smallest discharge air inner cross section of the discharge device, is determined, can also be formed at the first opening in the wall of the muffle. This is part of the blowing device. In particular, a minimum internal cross section of the exhaust air can also be formed at a second opening in the wall of the muffle, which is therefore regarded as belonging to the exhaust air device.

Preferably, the air supply inner cross section is between 10 mm and 25 mm, in particular during air supply operation. In an advantageous embodiment, it is provided that the smallest internal cross section of the exhaust air is between 16.7 mm and 41.7 mm. It can be provided that the ratio between the smallest supply air internal cross section and the smallest discharge air internal cross section is between 0.6 and 0.95.

In the blowing mode, the smallest blowing inner cross section of the blowing device can be up to 40% smaller than the smallest exhaust inner cross section of the exhaust duct. Depending on the position of the blower and the associated hose length and the associated flow resistance, the smallest blower inner cross section of the blower can also be approximately as large as the smallest blower inner cross section.

In an advantageous embodiment, it is provided that the length of the air supply line is between 250 mm and 500 mm. In an advantageous embodiment, it is provided that the length of the exhaust line is between 250 mm and 500 mm.

Preferably, the ventilator is activated at least temporarily during the air supply operation of the cooking appliance and a negative pressure is generated in the cooking chamber by the resulting suction of the medium out of the cooking chamber by the air outlet device. This facilitates, in particular, the automatic intake of fresh air into the cooking chamber via the open air supply device. This is because the air supply device is opened and in particular has a minimum air supply inner cross section which is smaller than the minimum air discharge inner cross section.

In an advantageous embodiment, provision is made for the cooking chamber to be air-tight or steam-tight in the blowing mode, with the exception of the openings in the wall (at which the blowing means on the one hand and the ventilation means on the other hand end). The fan can be designed such that it is operated in the active mode only at one operating speed. However, it can also be provided that the ventilator has at least two different operating rotational speeds that can be set accordingly. The cooking appliance has in particular a control unit. The control unit is used to set at least the operation of the ventilator.

The cooking appliance has in particular at least one sensor with which the humidity in the cooking chamber can be detected. This information may be provided to the control unit. In particular, the blast operation and/or the steam operation can be set on the basis of this information. In particular, the operation of the respective setting can also be changed in connection therewith. In an advantageous embodiment, it is provided that the cooking appliance has at least one sensor which detects the pressure in the cooking chamber. Based on this information, which can be provided to the control unit, it is possible to set the blowing operation or the steam operation or to change the set blowing operation or the set steam operation.

Provision can be made for the blower device to be switched on all the time during the blowing operation. This means that the blower is not completely switched off during this blower operation. Based on the advantageously illustrated embodiment in which the smallest supply-air inner cross section of the air supply device is smaller than the smallest exhaust-air inner cross section of the exhaust device, the air supply device exhibits a higher flow resistance than the exhaust device. If an underpressure is generated in the cooking chamber during the blowing operation, this automatically results in fresh air flowing into the cooking chamber by itself via the blowing device in order to equalize the underpressure in the cooking chamber. This creates a very advantageous embodiment which makes it possible to reduce the negative pressure and to supply fresh air into the cooking chamber during such a blowing operation.

In an advantageous embodiment, it is provided that, in the steam mode, which exhibits a mode different from the air supply mode, the minimum air-discharge inner cross section of the air-discharge device is set smaller by the throttle unit of the cooking appliance than the minimum air-discharge inner cross section of the air-discharge device in the air supply mode. In an advantageous embodiment, the air outlet inner cross section of the air outlet device is therefore reduced when the steam mode is set instead of the air supply mode. The individual flow ratios can thus be set better by the air outlet device. This also improves the desired setting in the cooking chamber. In an advantageous embodiment, it is provided that, during steam operation, the smallest air supply inner cross section of the air supply device is set smaller by the throttle unit of the cooking appliance than the smallest air supply inner cross section of the air supply device during air supply operation, wherein the air supply device is always switched on during steam operation. It is also possible with these advantageous embodiments to set individualized conditions in the cooking chamber more precisely and as desired.

Preferably, the minimum ventilation cross section of the ventilation device is reduced by at least 50% in the steam mode compared to the supply mode. In addition or alternatively, it can be provided that the minimum supply cross section of the air supply device is reduced by at least 50% in the steam mode compared to the supply mode. This is also a further advantageous embodiment, so that the individual conditions in the cooking chamber can be set quickly and very precisely in different operating modes of the cooking appliance.

The ratio for throttling or reducing the inner cross section is chosen in such a way that the escape of water from the cooking chamber is made difficult. A small overpressure, in particular an overpressure of less than 50 mbar, should be established in the cooking chamber. This can be achieved, for example, by throttling the supply air inner cross section by a value between 85% and 95%, in particular by a value of 90%, and by throttling the discharge air inner cross section by a value between 65% and 75%, in particular by a value of 70%. Depending on the hose geometry of the air supply and air discharge, it is also advantageous if the air supply inner cross section and the air discharge inner cross section are throttled to the same extent.

In an advantageous embodiment, it is therefore provided that the internal ventilation cross section and/or the internal supply cross section is reduced in the steam mode by the same percentage value compared to the supply mode. This means that, for example, the exhaust air inner cross section is reduced by a first percentage value and the supply air inner cross section is reduced by the same percentage value. However, it can also be provided that the inner cross section does not decrease by the same percentage value, but by a different percentage value. In the case of different percentiles, this again in an advantageous embodiment constitutes a specific and predetermined percentile ratio. This can be predetermined and set by the control unit. The throttle unit is actuated and operated accordingly, in particular by the control unit.

In an advantageous embodiment, it is provided that the air supply device is opened during steam operation and that the air supply device, during steam operation, forms an overpressure relief device for reducing the overpressure in the cooking chamber when it is used as a further air discharge device for discharging the medium from the cooking chamber. In particular, it can be provided that the ventilation device is closed during steam operation. In the steam mode, the exhaust air device may not be completely closed, but the exhaust air internal cross section at the smallest point of the exhaust air device may be set smaller than the supply air internal cross section at the smallest point of the supply air device. This also achieves a particularly advantageous solution for discharging the medium from the cooking chamber during steam operation. In this connection, a metered and on-demand reduction of the overpressure in the steam operation is achieved, in particular, by the air supply device.

In an advantageous embodiment, it is provided that the air supply device has a length of between 250 mm and 500 mm during steam operation, at least temporarily. The air supply device has a minimum air supply inner cross section between 250 mm and 500 mm in particular during steam operation.

In an advantageous embodiment, provision is made for a hood to be arranged in the underpressure region of the ventilator and adjacent to the end of the air outlet device facing away from the cooking chamber. The generation of the negative pressure in the cooking chamber can be set individually according to the position of the hood. In addition to the above-described advantageous embodiment with dual use of the blower, this embodiment can also be designed both in the steam mode and in a blower mode different from the steam mode.

In an advantageous embodiment, it can be provided that the cooking appliance can be provided with a hood even if the air blowing device is not used for the dual purpose of supplying and discharging the medium to and from the cooking chamber both in the steam mode and in the air blowing mode. In this embodiment, the air supply device is only completely opened during the air supply operation and can be closed during the air discharge operation. In this design with a hood, it can also be provided that the inner cross section of the exhaust and/or of the air supply device cannot be reduced during steam operation.

In steam operation, it is generally provided that steam which is desired to be generated in the cooking chamber and is added remains in the cooking chamber. Only the overpressure in the cooking chamber should be reduced.

In the steam operation, the air supply device forms a defined counterpressure to the steam pressure in the cooking chamber by means of its defined air supply inner cross section, in particular at the smallest points, and the length of the air supply device. This counter pressure prevents excessive evaporation from the cooking chamber. The air supply device therefore has the function of a ventilation device or of a steam outlet during steam operation. Depending on the actuation, in particular opening, of the hood, the auxiliary air can be sucked in directly at the ventilator itself, so that the negative pressure in the exhaust device is strongly reduced as a result. The negative pressure in the cooking chamber is accordingly reduced. The cage may also be configured as a slide valve. In such an embodiment, the hood is not pivoted, but is moved linearly.

By means of the design with the hood, a steam atmosphere with a high humidity in the cooking chamber can also be set relatively quickly. This, as with the above-described embodiments, is also a quick and efficient way of achieving this desired state or condition in the cooking chamber.

At the end of the steam cycle, all the steam in the cooking chamber can be sucked off very quickly by the ventilation device, in particular when the hood is completely closed. Then the cooler fresh air flows in again through the air supply device. In this embodiment, a drying function at the end of the steam operation is therefore also achieved. In the steam-free operation of the cooking appliance, it is also possible to configure the hood such that a defined humidity and a specific cooking chamber atmosphere are produced in the cooking chamber. Regardless of this, the humidity in the cooking chamber can also be measured and set by the ventilation device. In particular, a correspondingly precise atmosphere control is achieved here. Especially when this hood can be positioned in a number of different defined positions in embodiments with a hood.

In an advantageous embodiment, it is provided that the cooking appliance has a manipulator for the hood. This manipulator may be a motor or a slide valve or an eccentric or a wax actuator.

In an advantageous embodiment, it is provided that an opening in the wall of the muffle, at which the first end of the air supply device ends, through which fresh air flows into the cooking chamber during the air supply operation, also forms an opening for at least one further functional component of the cooking appliance. This opening is thus used for multiple functions. The number of openings in the muffle can be kept small. This opening can also be used for a grill sensor or grill thermometer, for example.

In the proposed cooking device, in particular, the humidity can also be actively and precisely reduced. However, a significant advantage over the overpressure systems known from the prior art is achieved in this respect by the negative pressure prevailing in the cooking chamber and being able to be generated in a defined manner. Furthermore, a reduced number of components is achieved, since the air supply device can also be used in different operations with multiple functions. In the proposed cooking device, in particular, only one throttle unit, in particular a valve, is required in order to be able to achieve the optionally intended internal cross section of the air outlet device and/or of the air supply device. In the dry operating mode of the cooking appliance, in a subsequent operating mode, such as an automatic program, the advantages of a targeted reduction of the steam before the door is opened and before the cooking chamber is dried are also provided. The fresh air supply can be used independently of this to improve the toasting sensor function in the cooking appliance.

In the proposed cooking device, therefore, a drying operation can also be carried out as a subsequent operation after the steam operation. Particularly in order to reduce the amount of steam in the cooking chamber highly on demand and quickly. The corresponding application can be carried out primarily in an automatic program. In particular, the humidity in the cooking chamber can thus also be reduced better before the door is opened or at the end of the cooking operation. Also this results in corrosion protection to dry the cooking chamber after steam operation. In particular, the cooking result in steam operation can also be improved, in particular because the steam generated is set as desired and excess steam is discharged in a targeted manner. It is also possible to reduce the humidity precisely and as needed during the humidity control. The measurement result of the sensor detecting the parameter in the cooking chamber can also be improved, since this sensor preferably requires a somewhat limited supply of air for a better working mode, which can be achieved with the proposed system. Furthermore, with the proposed cooking device also a faster cooling down can be achieved and thus a fast cooling function can be provided. In particular, the idle time of the ventilator can also be reduced by the cooking appliance. This makes it possible to reduce the operating noise. In particular, energy-efficient operation is also possible, since no air supply is required during the heating phase and the air supply input is regulated during the air supply operation. In particular, the described embodiments are also possible in cooking devices which are not cooking devices for which energy-efficient operation is possible. An improved steam outlet is achieved, whereby the energy balance of the cooking device is improved for this purpose. The cooking device is in particular a steam cooking device. Which has a steam generating device. With such a steam generating device, steam for cooking the cooking product is generated in a targeted manner in the cooking chamber.

Another aspect of the invention relates to a method for operating a cooking apparatus. The cooking device is configured according to the above aspect or an advantageous embodiment of the above aspect. The air supply device is used for supplying fresh air into the cooking chamber in the air supply operation of the cooking device. In a steam operation of the cooking appliance, which is different from the air supply operation, the air supply device serves to discharge the medium from the cooking chamber. In the blowing operation, therefore, fresh air is introduced into the cooking chamber via the blowing device and, in the steam operation, the medium is discharged from the cooking chamber via the blowing device. The blower device is kept open, in particular both in the steam mode and in the blower mode. The blower is therefore not completely switched off in both operations. In the steam mode, the supply air inner cross section of the air supply device may be reduced at the point of minimum compared to the point of minimum of the supply air inner cross section in the air supply mode. In particular, the inner cross-section of the supply air at the smallest point is set smaller than the inner cross-section of the discharge air at the smallest point in the discharge device during the supply operation. In the blowing mode, the medium is sucked out of the cooking chamber by the activated ventilator through the subsequently opened ventilation device. Since a negative pressure is generated in the cooking chamber by this operation, fresh air is automatically supplied into the cooking chamber by the air supply device. The supply air is particularly advantageously fed automatically, in particular on account of the abovementioned advantageous internal cross sections in the supply air device and in the exhaust air device during the supply air operation.

The expressions "upper", "lower", "front", "rear", "horizontal", "vertical", "depth direction", "width direction", "height direction" indicate given positions and orientations when the device is used as specified and arranged as specified.

Further features of the invention emerge from the claims, the figures and the description of the figures. The features and feature combinations mentioned in the foregoing description, and those mentioned in the following description of the drawings and/or shown in the drawings alone, can be used not only in the respective combinations indicated, but also in other combinations or alone without departing from the scope of the invention. Embodiments of the invention which are not explicitly shown and described in the drawings, but which can occur or result from a combination of features separate from the illustrated embodiments, are therefore also to be considered as being included and disclosed. Embodiments and combinations of features, which do not have all the features of the initially written independent claims, are therefore also regarded as disclosed.

Drawings

Embodiments of the invention are explained in more detail below with the aid of schematic drawings. In the figure:

FIG. 1 is a schematic vertical cross-sectional view of an embodiment of a cooking apparatus;

fig. 2 is a corresponding sectional view as in fig. 1, but in which the cooking appliance is shown in steam operation;

fig. 3 is a schematic view of the inner cross-sections of the air exhaust means and the air supply means of the cooking device in an air supply operation on the one hand and in an air exhaust operation on the other hand; and is

FIG. 4 is a schematic partial view of an embodiment of a cooking apparatus with a hood in the negative pressure region of the ventilator; and is

In the figures, identical or functionally identical elements are provided with the same reference symbols.

Detailed Description

Fig. 1 shows a cooking appliance in a schematic vertical sectional view. The cooking appliance is here a cooking appliance 1. It may also be a cooking appliance that operates without steam.

The cooking apparatus 1 has a housing 2. A muffle 3 is arranged in the housing 2. The muffle 3 defines a cooking chamber 8 with a bottom wall 4, a rear wall 5, a top wall 6 and opposite side walls (of which only the side wall 7 can be seen). On the front side, the cooking chamber 8 can be closed by a door 9 of the cooking apparatus 1. The cooking appliance 1 furthermore has a ventilator 10. In the exemplary embodiment, the ventilator 10 is arranged in the height direction (y direction) above the cooking chamber 8 and in particular also above the muffle 3. For this purpose, a receiving space 11 is formed in the housing 2. Furthermore, the cooking apparatus 1 has an air supply device 12. The air supply device 12 has at least one air supply line 13. The air supply line 13 opens with a first line end 14 into an opening 15 in the rear wall 4. Another component of the cooking device 1 can also be guided to this opening 15. This opening 15 is then used in at least a dual function. The second line end 16 leads in the exemplary embodiment into the receiving space 11. The second end 16 can also be guided or guided outward at an opening 23 in the housing 2. Fresh air can thus enter the fresh air line 13.

Furthermore, the cooking apparatus 1 has an air exhaust device 17. The exhaust device 17 has at least one exhaust line 18. The exhaust line 18 opens with a first end 19 to an opening 20 in the rear wall 4. A second line end 21 of the exhaust line 18 opens into a vacuum region 22 of the ventilator 10. The ventilator 10 is in this regard arranged in the channel 24. Channel 24 is defined by wall 25 and wall 26. On the front side, an opening 27 is formed at the housing 2. The exhaust air AL is discharged from the casing 2 through this opening 27. The opening 27 is formed in this respect in an overpressure region 28 of the ventilator 10.

It can be provided that the blowing device 12 has more than one blowing line 13. It can be provided that the exhaust device 17 has more than one exhaust line 18. The cooking appliance 1 furthermore has a control unit 29. This control unit is shown only symbolically in fig. 1 in terms of design and position. The control unit 29 is at least designed in particular to control the ventilator 10.

It can also be provided that the cooking device 1 has sensors 30, only symbolically in terms of position and number. The sensor 30 may be a humidity sensor. Additionally or alternatively, the sensor 30 may be a pressure sensor. It is thus possible to detect the humidity and/or the pressure in the cooking chamber 8. At least one sensor 30 is connected to the control unit 29.

As can be seen in fig. 1, the opening 15 is arranged further down in the embodiment shown than the opening 20, viewed in the height direction. The first opening 15 of the air supply device 12 is thus arranged at a lower level than the second opening 20 of the air exhaust device 17. In particular, the air supply device 13 is provided as an air discharge device for discharging the medium from the cooking chamber 8 during steam operation of the cooking appliance 1. In the air supply operation of the cooking appliance 1, the air supply device 12 is configured to supply fresh air into the cooking chamber 8.

Fig. 1 shows the air supply operation. In particular, in such a blowing mode, it is provided that the ventilator 10 is activated. The exhaust 17 is opened. The blower 12 is turned on. The air outlet device 17 has in particular a minimum air outlet inner cross section a 1. The air supply device 12 has a minimum air supply inner cross section a 2. The exhaust air internal cross section a1 refers to the point of the exhaust air device 17 having this smallest exhaust air internal cross section a 1. The region with the supply air inner cross section a2 is a region of the air supply device 12 at which the air supply device 12 has the smallest supply air inner cross section. These corresponding points can be formed in the

lines

13 or 18. They may also be formed, for example, at the

ends

14 or 19. They may also be formed at the

openings

15 or 20.

With this design and the activated ventilator 10, the medium M is sucked out of the cooking chamber 8. A negative pressure is thereby generated in the cooking chamber 8. Based on the underpressure and the

open lines

13 and 18 and the special inner cross-sectional dimensioning, fresh air F is automatically sucked in by the air supply device 12 and automatically enters the cooking chamber 8.

The cooking chamber 8 is also steam-tight or air-tight, in addition to the

openings

15 and 20.

The ratio between the supply air internal cross section a2 and the discharge air internal cross section a is preferably between 0.6 and 0.95.

Fig. 2 shows a cooking appliance 1 corresponding to that shown in fig. 1. However, fig. 2 shows a steam operation differently from fig. 1. Steam is generated in the cooking chamber 8 by the steam generating means 34 of the cooking apparatus 1. The position and design of the steam generating device 34 is not final but merely indicative. In this steam mode, at least the blower device 12 is also switched on. The blower is therefore not completely switched off. The exhaust device 17 is preferably opened during steam operation. But the exhaust can also be completely closed. The cooking appliance 1 has a throttle unit 31, as is only symbolically shown in fig. 2. The throttle unit 31 may be a valve, in particular only a single valve. The inner cross section of the air exhaust device 17 and/or the air supply device 12 can be changed by means of the throttle unit 31. In the steam mode, it is provided that, in an advantageous embodiment, the smallest supply air inner cross section is set smaller than in the supply air mode. In the steam mode, it is provided that the minimum internal cross-section of the exhaust air is set smaller than in the supply air mode. It can be provided that the inner cross section decreases by the same percentage value. However, it can also be provided that the percentage change of the supply air internal cross section in the steam mode differs from the percentage reduction of the exhaust air internal cross section in the steam mode. The throttle unit 31 is not shown in fig. 1 for the sake of clarity, but is also present there.

During this steam operation, an overpressure is generated in the cooking chamber 8. In order to be able to reduce an undesired overpressure in the cooking chamber 8, the air supply device 12 is used to discharge the medium from the cooking chamber 8 during such a steam operation. The air supply device 12 is an overpressure reduction device for reducing an undesired overpressure in the cooking chamber 8, which overpressure exceeds a desired overpressure, in particular in such steam operation. As shown in fig. 2, the medium M is thus discharged from the cooking chamber 8 to the outside by the air blower 12.

Fig. 3 shows an exemplary cross-sectional view of the air outlet device 17 and the air supply device 12 in the top view. The smallest inner cross-sections a1 and a2 are shown in particular. In the lower view of fig. 3, a reduced cross-sectional configuration of the air supply device 12 and the air exhaust device 17 is shown in comparison with this. It can be seen that the air supply inner cross section of the air supply device 12 is reduced compared to the upper drawing in fig. 3. In the exemplary embodiment, the inner air-discharging cross section of the air-discharging device 17 can also be seen in the lower drawing, which is clearly smaller than in the upper drawing. Provision can be made for the exhaust device 17 to be completely closed when the steam mode is set. The ventilation device 17 can also be slightly open, but has a reduced inner cross section compared to the supply air operation.

Fig. 4 shows a simplified illustration of a partial section of the cooking appliance 1. It may be a cooking apparatus 1 according to fig. 1 to 3. But may be a different cooking apparatus. In various cooking devices, it can be provided that the air supply device 12 is not used to discharge the medium from the cooking chamber 8 during steam operation.

In fig. 4, the cooking appliance 1 has a hood 32. The shroud 32 may also be a spool valve. The enclosure 32 is preferably disposed in the negative pressure region 22 of the ventilator 10. The hood is arranged in particular in the region of the second line end 21 of the exhaust device 17. The hood 32 may be controlled by the control unit 29. The cover can thus be opened or closed. The cover may additionally assume at least one intermediate position in addition to the two discrete positions of fully closed and fully open. The hood 32 is pivotally supported. The cover can however also be supported in such a way that it can only move linearly. If the hood 32 is opened, for example during a blowing operation, the underpressure in the cooking chamber 8 is reduced, in particular can be reduced to a greater extent. The air L is then sucked in through an opening 33 formed in the housing forming the ventilation channel into which the ventilator 10 projects. The medium is therefore sucked off a small amount or less from the cooking chamber 8 by the ventilation device 17. In this embodiment, it can be provided that, when switching between the air supply mode and the steam mode, no reduction of the inner cross section of the air outlet device 18 and/or of the air supply device 12 takes place. The actuation of the cap 32 can be adjusted by means of a motor, a slide valve, an eccentric or a wax actuator as possible examples.

List of reference numerals

1 cooking appliance

2 casing

3 muffle furnace

4 bottom wall

5 rear wall

6 roof

7 side wall

8 cooking chamber

9 door

10 ventilator

11 accommodation chamber

12 air supply device

13 blast pipeline

14 first pipe end

15 opening

16 second pipe end

17 air exhausting device

18 exhaust pipeline

19 first end

20 opening

21 second pipe end

22 negative pressure region

23 opening

24 channel

25 wall

26 wall

27 opening

28 overpressure zone

29 control unit

30 sensor

31 throttling unit

32 cover

33 opening

34 steam generating device

y height direction

F fresh air

L air

M medium

AL exhaust

A1 inner cross section of air exhaust

A2 air supply inner cross section

Claims

1. Cooking apparatus (1) with: a housing (2) in which a cooking chamber (8) is formed, wherein the cooking chamber (8) is defined by walls (4, 5, 6, 7) of a muffle (3) of the cooking device (1); and having an air supply device (12) with which fresh air can be introduced into the cooking chamber (8) during an air supply operation of the cooking appliance (1); and having an air-discharge device (17) separate from the air-supply device (12), with which the medium can be discharged from the cooking chamber (8); and having a ventilator (10) with which an air flow (L) can be generated, wherein the ventilator (10) is connected to an air exhaust device (17), characterized in that the air supply device (10) serves as a further air exhaust device for discharging the medium (M) from the cooking chamber (8) during steam operation of the cooking appliance (1).

2. Cooking device (1) according to claim 1, characterized in that the air supply means (12) have at least one air supply duct (13) ending with a first duct end (14) at a first opening (15) of the wall (4) of the muffle (3) and/or the air exhaust means (17) have at least one air exhaust duct (18) ending with a first duct end (19) at a second opening (20) of the wall (4) of the muffle (3).

3. Cooking device (1) according to claim 2, characterized in that the first opening (15) of the air supply means (12) is arranged at a lower level than the second opening (20) of the air exhaust means (17) seen in the height direction (y) of the cooking device (1).

4. Cooking device (1) according to one of the preceding claims, characterized in that in a blowing operation the blowing means (12) have at least at one point a smallest blowing inner cross section (a 2) which is smaller than the smallest blowing inner cross section (a 1) of the blowing means (17).

5. Cooking device (1) according to claim 4, characterized in that the ratio between the supply air internal cross-section (A2) and 25 mm and/or the minimum exhaust air internal cross-section (A1) is between 16.7 mm and 41.7 mm and/or between the supply air internal cross-section (A2) and the minimum exhaust air internal cross-section (A1) is between 0.6 and 0.95.

6. A cooking appliance (1) as claimed in any one of the preceding claims, characterized in that the ventilator (10) is activated at least temporarily during the blowing operation and an underpressure is generated in the cooking chamber (8) by the resulting suction of the medium (M) out of the cooking chamber (8) via the air exhaust device (17).

7. Cooking device (1) according to one of the preceding claims, characterized in that in steam operation the smallest exhaust air internal cross section of the exhaust air means (17) is set smaller by the throttle unit (31) of the cooking device (1) than the smallest exhaust air internal cross section of the exhaust air means (17) in air supply operation, and in steam operation the smallest supply air internal cross section of the air supply means (12) is set smaller by the throttle unit (31) of the cooking device (1) than the smallest supply air internal cross section of the air supply means (12) in air supply operation, wherein at least the air supply means (12) is opened in steam operation.

8. Cooking appliance (1) according to claim 7, characterized in that the smallest air-exhaust internal cross-section of the air-exhaust means (17) is reduced by at least 50% in the steam mode of operation compared to the air supply mode and/or the smallest air-supply internal cross-section of the air-supply means (12) is reduced by at least 50% in the steam mode of operation compared to the air supply mode.

9. Cooking device (1) according to any of the preceding claims, characterized in that the air supply means (12) is switched on in steam operation and that the air supply means (12) is an overpressure reducing means for reducing the overpressure in the cooking chamber (8) in steam operation when it is used as an air exhaust means for exhausting medium from the cooking chamber (8).

10. Cooking device (1) according to one of the preceding claims, characterized in that the air supply means (12) have a length of between 250 mm and 500 mm and a minimum air supply inner cross section of between 10 mm and 25 mm at least temporarily during steam operation.

11. Cooking device (1) according to one of the preceding claims, characterized in that a hood (32) is arranged in the negative pressure region (22) of the ventilator (10) and adjacent to the end of the air exhaust means (17) facing away from the cooking chamber (8), wherein the negative pressure generation in the cooking chamber (8) can be set depending on the position of the hood (32).

12. Cooking device (1) according to any of the preceding claims, characterized in that the cooking device (1) has a manipulator for the hood (32).

13. Cooking device (1) according to any of the preceding claims, characterized in that at least one further functional component of the cooking device (1), in particular a grill thermometer, is introduced into an opening (15) in the wall (4) where the air supply means (12) end.