EP2472187A1 - Cooking device and method for operating same - Google Patents

Abstract

The cooking device (1) has a cooking chamber (2), which is heated by a heat source and a door (4) for closing the cooking chamber. A blower for rapid cooling of the cooking chamber is provided outside the cooking chamber in order to convey fresh air into the cooking chamber. The blower is formed as a radial blower. An independent claim is also included for a method for operating a cooking device.

Description

The present invention relates to a cooking appliance with a blower arranged outside the cooking chamber and a method for operating such a cooking appliance.

Cooking appliances are subject to a constant process of development in order to meet the ever-increasing requirements for energy efficiency. For this purpose, the cooking chamber of cooking appliances is getting better and better insulated. This has the consequence that the temperature in the cooking chamber sinks only very slowly, even if the radiators are completely switched off.

In some situations, however, just such a temperature stability is not desired or even disturbing. If a cooking appliance has, for example, a pyrolysis-based cleaning function, under certain circumstances it may take a long time for the cooking appliance to be ready for use again, since the temperature of the cooking chamber must fall below a certain temperature until the cooking-chamber door can be reopened. This limits the ease of use.

But even with normal cooking processes, such as the baking of a cake, the slow sinking of the oven temperature may be undesirable. If the dough has reached a desired degree of browning, the radiators automatically turn off, for example, in the case of an automatic program. However, the only slowly decreasing residual heat in the cooking chamber can lead to a further undesirable browning. As a result, it can happen in the worst case that a food is inedible by excessive browning, if the user does not promptly remove the food from the oven or at least the cooking chamber door opens.

Even within a cooking process, it may be advantageous to cool the oven quickly. If you use, for example, an oven for frying a roast, it must first be operated very hot to achieve a crust with a desired browning. Subsequently, however, the cooking space must be lowered quickly to a relatively low temperature in order to continue to cook the roast with a low temperature for several hours in the oven. Even in such a case, the user must actively intervene in the cooking process and, for example, open the door of the cooking chamber to cool the cooking chamber.

Such intervention is annoying for a user. In addition, the intervention in the cooking process, for example opening the door, can also be easily forgotten or in some situations not possible when the user is about to do other things. As a result, the cooking result can be greatly deteriorated.

For automatic cooling of the cooking chamber describes, for example, the DE 10327420 A1 the use of a humidifier. By means of the Beschwadungsvorrichtung liquid is passed to the fan of the blower device of the cooking appliance, whereby small liquid droplets are introduced into the cooking chamber by the rotational movement of the fan wheel. Due to the evaporative cooling of the droplets, the cooking space is cooled. A disadvantage of such a method for cooling the cooking chamber, however, is that the humidity of the cooking chamber is significantly changed. This can possibly lead to a deterioration of the cooking result.

Another method for cooling the cooking chamber shows the DE 102008012681 A1 , Here, using a specific valve, the hot air blower of the cooking chamber is used either for circulating the air in the oven or for the intake of fresh air. It should be generated in the same line an opposite flow of incoming fresh air and outflowing moist cooking chamber air. The disadvantage here, however, is that the fresh air is sucked in from the negative pressure area behind the hot air blower. As a result, only a small air flow can be used for cooling, whereby long periods are required for cooling, in which the cooking process continues.

It is therefore an object of the present invention to provide a cooking appliance available that allows effective and rapid effective cooling of the cooking chamber even with well insulated devices.

This object is achieved by a cooking appliance having the features of claim 1 and by a method for operating a cooking appliance having the features of claim XXXX.

The cooking appliance according to the invention comprises at least one cooking chamber which can be heated by means of at least one heating source. So that the heat is held in the cooking chamber, at least one door closing the cooking chamber is provided in order to close the cooking chamber. In order to allow a rapid cooling of the cooking chamber, at least one fan is further provided. The fan is arranged outside the cooking chamber and adapted and adapted to direct cold fresh air into the cooking chamber.

Such ausgestaltetes cooking appliance offers many advantages. A considerable advantage is that a large amount of cold fresh air can be blown into the cooking chamber through the fan arranged outside the cooking chamber. This allows fast and efficient cooling even with well-insulated garages. Since the blower is preferably not arranged in the vacuum region of the hot air blower, a particularly good flow through the cooking chamber can be achieved.

In particular, amounts of air of 250-500 l / min, preferably 500-1000 l / min and particularly preferably 1000-2000 l / min for the flow through the cooking chamber are advantageous in order to achieve effective cooling in a suitable time. In particular, air quantities of at least 800 l / min are preferred, whereby about 1000 l / min are also very suitable. Depending on the application but also smaller or larger amounts of air may be appropriate.

In preferred embodiments, the fan is designed as a radial fan. As a result, in contrast to a design as an axial fan, a substantially higher pressure can be achieved with the same amount of transported air. This allows a particularly effective and rapid cooling of the cooking chamber can be achieved.

Particularly preferably, the fan is designed to be infinitely variable. In particular, a DC fan is suitable for this purpose. By such an embodiment, the air flow conducted into the cooking chamber can be well adapted to the required amount of air but also to a particularly suitable inflow pressure.

For this purpose, in preferred embodiments, at least one control device can be provided. About such a control device, the speed of the fan can then be adjusted well. In this case, in particular, one or more sensors can be provided, via which the control device can evaluate which air quantity or which flow rate are advantageous.

Since the blower is arranged outside the cooking chamber, the air must be blown through a designated opening in the cooking chamber. Therefore, in preferred embodiments, a seal between the fan and the cooking chamber is provided. This can be achieved that warm air can not escape from the oven when the fan is not in operation.

In this case, as a seal, a flap device is preferred, which is suitable and oriented to be opened by the air flow generated by the blower. If the blower is not switched on, the flap device can be replaced by a spring, for example held in a closed position. When the blower is switched on, the air flow against the spring force can open the flap and thereby release the access to the cooking chamber. When the blower is switched off again, the flap closes automatically again, whereby the access to the cooking chamber is closed again. Preferably, the flap device is further configured so that the insulation of the cooking chamber is not affected.

In addition to a flap device just described, in other particularly preferred embodiments, inter alia, an electronically controllable flap device is provided as a seal. As a result, the flap could be opened as needed, closed, or else brought into another intermediate position. In particular, the control device could be used for this purpose.

By the blower can preferably be dehumidified and the cooking chamber. This can be removed from the cooking chamber, for example, during cooking moisture. In this case, the fan according to the invention can in particular replace a Garraumentfeuchtung. The air flow generated by the blower could, for example, even be passed through an existing hole pattern for a Garraumentfeuchtung in the cooking chamber. For effective cooling, it may be necessary to extend the hole pattern to a required size. In particular, an entrance surface for the air flow of about 11 cm ^{2 is} preferred.

Depending on the arrangement of the fan, a connecting channel between the fan is provided in particularly preferred embodiments. This connection serves to effectively direct the airflow from the fan into the cooking chamber. In particular, the channel should not be too long and should not contain unnecessarily many sheets. Channel lengths of less than 50 cm and in particular less than 30 cm are to be preferred. Furthermore, it is advantageous not to provide more than one arc, that is to say an angling for the connecting channel. This can be achieved that the pressure losses are not unnecessarily large.

In particularly preferred embodiments, at least one opening is provided, can be derived by the hot air from the cooking chamber. As a result, a particularly effective rapid cooling of the cooking chamber can be achieved. In this case, cold fresh air is blown by the blower in the cooking chamber, which cools the cooking chamber and pushes the hot air through the opening of the cooking chamber. In this case, such an opening can be made available inter alia by the cooking chamber opening. But other openings may be advantageous, which may be arranged in particular laterally or rearwardly of the cooking chamber. This would better avoid contact of a user with warm or hot air.

Particularly preferably, the opening in the lower region of the cooking chamber door is arranged. It is conceivable that a flap is integrated into the door, which dissipates the air from the cooking chamber downwards, especially in the open state. The opening could be opened separately.

A manual opening is conceivable. In particular, however, an automatic opening is useful and preferred. In this case, the opening can be closed automatically by a closure device. An automatic opening is preferred.

In particularly preferred embodiments, the closure device comprises the cooking chamber door. This is suitable and is designed to be automatically opened at least a gap. As a result, the air guided by the blower into the cooking chamber could easily escape from the cooking chamber through a gap between the cooking chamber door and the cooking chamber opening, as a result of which the rapid cooling is effectively supported. Then the oven door can then be automatically closed again.

The inventive method is particularly suitable for operating a cooking appliance with at least one thermally heated cooking chamber. At least one door closing the cooking space is provided on the cooking appliance in order to close the cooking space. Outside the cooking chamber at least one fan is arranged, which blows cold fresh air into the cooking chamber to cool it quickly.

An advantage of such a configured method is that can achieve a very effective flushing of the cooking chamber with cold fresh air by the arrangement of the fan outside the cooking chamber. In particular, when using a radial blower considerable amounts of fresh air can be used in a short time to lower the oven temperature to the desired temperature.

Preferably, an opening is automatically opened at least a gap to support the rapid cooling. As a result, air can escape quickly from the cooking chamber, whereby the cooling is accelerated.

Particularly preferably, the fan is started at least for a short time before each opening of the cooking chamber door. As a result, jerky escape of hot vapor can be better prevented. The fan can be started by hand or especially automatically.

Figur 1

eine schematische perspektivische Ansicht eines erfindungsgemäßen Gargerätes, das als Backofen ausgeführt ist; und

Figur 2

eine schematische Darstellung eines Gargerätes in einer geschnittenen Ansicht mit einem außerhalb des Garraumes angeordneten Gebläse zur Schnellabkühlung des Garraumes.

Further advantages and features of the present invention will become apparent from the embodiment, which will be explained below with reference to the accompanying figures. Showing:

FIG. 1

a schematic perspective view of a cooking appliance according to the invention, which is designed as a baking oven; and

FIG. 2

a schematic representation of a cooking appliance in a sectional view with a fan arranged outside the cooking chamber for rapid cooling of the cooking chamber.

FIG. 1 shows a cooking appliance 1 according to the invention that is designed here as oven 30 for installation in a furniture body. The oven 30 comprises a housing 24 in which a cooking chamber 2 which can be closed with a door 4 is arranged, in which food can be prepared using different operating profiles. Among other things, it is possible to select between different operating modes via a control panel 23 shown here only schematically. In this case, different heat sources 3 can be used to prepare the food. For example, a recirculating air mode, top and bottom heat, and a grill function can be used. The temperature can also be adjusted. The control panel 23 may be designed as a touch panel or include controls not shown in detail.

Due to ever increasing requirements regarding the energy efficiency of household appliances, the cooking appliance 1 and in particular the cooking chamber 2 are very well insulated, whereby the heated cooking chamber 2 loses the introduced heat even after switching off the heat source 3 only very slowly. Although this is a great advantage for the energy balance of a cooking appliance 1, but also brings disadvantages in some situations.

For example, a user must immediately remove food from the cooking chamber once it is cooked to prevent browning or even burning of the food. Optionally, the cooking chamber door must be opened by hand to release the hot air from the oven.

Even if initially a very high temperature is used, which subsequently has to be reduced rapidly, the intervention of the user has hitherto been necessary. This is not very practical for a user. In addition, for example, the opening of the door at the end of a cooking process can also be easily forgotten. Especially with the use of automatic programs, it would be very convenient for a user if he no longer had to intervene in the cooking process after starting the program.

Also in the pyrolysis operation can comfort comfort arise for the user. If the device is finished with the pyrolysis operation, it may take a very long time until the cooking appliance is ready for use again. For safety reasons, the door can only be opened again after a certain temperature, which can take a long time to cool down up to 500 ° C.

In order to allow rapid cooling of the cooking appliance 1, which cools the cooking chamber 2 on the one hand fast, but on the other hand also reliable, is in FIG. 2 outside the cooking chamber 2, a fan 20 is arranged. This is suitable and is designed to conduct cold fresh air 9 in the cooking chamber 20. By the cold air 9 of the cooking chamber 2 is effectively cooled.

In the embodiment shown here, the blower 20 is designed as a radial fan 12, whereby a very effective air delivery is ensured. In particular, air quantities of more than 800 l / min are preferred. The blower shown here can deliver about 1000 l / min. Even larger or smaller amounts of air can be advantageous depending on the application. Depending on the requirements, it is advantageous to adapt the fan 20 in accordance with the required power. Due to the large capacity of a radial fan 12, the cooling of the cooking chamber 2 can be achieved quickly and reliably.

In preferred embodiments, the fan 20 is further designed as a DC fan 14, whereby a stepless control is possible. In this case, the control device 5 control the fan 20, wherein a sensor 11 is provided, which can determine the state of the blower 20 in the example shown here. About an actuator 6, the fan can be started at any time by hand as needed.

The fan 20, which is arranged here in a housing 13, blows the cold fresh air 9 via a connecting channel 19 in the cooking chamber 2. Thus, the air flow 17 is not attenuated too much, preferably at most one sheet 28 is provided in the connecting channel 19. As a result, the air flow 17 is influenced as little as possible by a deflection. Of course, depending on the structure of the cooking appliance or depending on the space also several sheets 28 may be provided or necessary. But then it may be appropriate to use a correspondingly stronger blower 20 in order to achieve a suitable air flow rate again.

It should also be ensured that the connecting channel 19 is not laid out too long. In order not to impair the performance of the blower 20, a length of less than 30 cm is preferred. Also shorter or longer connecting channels 19 are conceivable depending on the cooking appliance 1, but possibly the fan 20 would have to be tuned to ensure adequate cooling.

The connecting channel 19 has in the in FIG. 2 embodiment shown, a seal 15 between the blower 20 and the cooking chamber 2. The seal 15 may for example be designed as a valve, which is advantageously controllable. In the cooking appliance 1 according to the invention FIG. 2 However, a flap device 16 is provided which closes the access 29 to the cooking chamber 2. The flapper device 16 is designed to be held in a closed position by, for example, a spring when the fan 20 is not turned on. The closed position of the flapper 16 may be possible in many ways not discussed further herein. It is important only that the flap device is at least closed when the fan 20 is not turned on.

If the blower 20 is turned on, the air flow 17 of the blower 20 can then press the flap device 16 and thus release the access 29 to the cooking chamber 2. By such a flap device 16 prevents hot air from the cooking chamber in the area between cooking chamber 2 and housing 24 can escape.

In other embodiments, an electronically controlled flap device 18 may be provided. This could, for example, be connected to the control device 5 and be opened and closed as required.

For example, some cooking devices 1 have an opening in the upper region of the cooking chamber, via which the dehumidifying of the cooking chamber 2 takes place during a cooking process. This opening can be designed as a hole pattern. Since the fan 20 can replace the function of Garraumentfeuchtung, it is also possible in particular to use the space provided for Garraumentfeuchtung hole pattern as access 29 for the air flow 17. Eventually, the hole pattern must be adjusted in size so that a sufficient amount of cold fresh air 9 can be pressed into the cooking chamber 2. In the embodiment shown here, an access of about 11 cm ^{2 is} provided, which corresponds here to a hole pattern of 5.2 cm diameter with about 28 holes. It is thereby also possible to retrofit cooking appliances with a fan 20 for cooling the cooking chamber 2.

In order to achieve a particularly effective and rapid cooling of the cooking chamber 2, is in the in FIG. 2 shown embodiment, an opening 21 in the cooking chamber 2 is provided, which can be closed by a closure device 22. In this case, the opening 21 of the cooking chamber opening 25 and the closure device 22 of the cooking chamber door 4 corresponds to the cooking appliance 1 shown here. However, other arrangements of the opening 21 are also advantageous. For example, a lateral opening 21 or an opening 21 at the rear end of the cooking appliance makes sense.

An opening 21 in the lower region of the door 4 is an advantageous embodiment. In this case, the opening 21 is covered by a closure device 22, which is designed as a flap. This can then be opened so that the hot air is deflected downwards.

In particular, an automatic opening of the opening 21 is possible. For this purpose, an opening device 10 is provided in the embodiment shown here, which is suitable and designed to open the closure device 22 at least one gap 7 far. Intervention by the user is then not necessary since the opening device 10 can automatically open the closure device 22 designed as a cooking chamber door 4 in the example shown here.

The opening device 10 can have a wide variety of configurations. For example, the opening device 10 may be operated by a motor which, for example, displaces a rod and thus urges the door 4 a gap 7 far. Also, a hydraulic, pneumatic and / or magnetic mechanism is advantageous for the formation of the opening device 10.

Other suitable mechanisms, such as a motorized rotation axis on the door, may be provided for opening and closing the cooking chamber door. In any type of opening device 10 is also preferred that the opening device is arranged as inconspicuous for design reasons. For this purpose, opening devices 10 such as toothed racks or pressure cylinders can be arranged in the bars of the cooking appliance housing 24. As a result, the opening devices 10 would be housed substantially hidden.

In the in FIG. 2 illustrated embodiment, the opening via a controllable pressure cylinder 26 which opens by means of a rod 27, the door 4 a bit wide. In this case, different opening widths 7 can be adjusted by the opening device 10. A particularly preferred gap width 7 is between 0.5 cm and 5 cm, wherein in FIG. 2 a gap 7 of 1.9 cm is set. Even larger and smaller opening widths 7 may be advantageous.

By thus a gap 7 wide open door 4 can then escape the hot air 8 effectively from the cooking chamber 2, whereby a particularly rapid cooling of the cooking chamber 2 takes place. When the desired temperature is reached, the rod 27 can again move back into the cylinder 26, whereby the door 4 is closed again. The force required to close the door 4 can come either from the door 4 itself, but it is also conceivable that a pulling device, not shown here, such as a spring is provided, which uses the door 4 back to the cooking chamber 25.

If the desired oven temperature is reached, of course, makes sense to turn off the fan 20 again.

In order to be able to set different opening widths 7 of the opening device 10, the control device 5 can also control the opening of the door 4. In this case, the control device 5 controls the particular automatic opening of the door 4 and can integrate the automatic opening of the door 4 in various operating profiles.

The manual opening of the cooking chamber door 4 is possible because the opening device 10 can be triggered via the actuating device 6. This can be done either directly or via the control device 5.

Furthermore, the sensor 11 is also in communication with the opening device 10. The sensor 11 may for example determine the position of the door 4, the temperature of the cooking chamber 2 and other parameters. Taking into account the values determined by the sensor 11, the control device 5 can also suppress, for example, the opening of the door 4 or else it can be carried out stepwise if, for example, the temperature in the cooking chamber 2 is above a critical value. Then the door 4 would first open a small gap 7, so that the jerky escape of too hot vapor is avoided. After a first cooling, the door 4 can then be opened either directly to the desired opening width 7 or even gradually to cool the cooking chamber 2 as quickly as possible.

To cool the cooking chamber 2 even better, for example, the hot air blower 31 or another fan of the cooking appliance 1 can support the cooling.

It is within the skill of one skilled in the art to modify the described embodiments in a manner not shown in order to achieve the effects described, without departing from the scope of the invention.

Claims (16)

Cooking appliance (1) with at least one cooking chamber (2), which can be heated via at least one heating source (3), and with at least one door (4) closing the cooking chamber (2),
characterized,
that outside the cooking chamber (2) at least one fan (20) for rapid cooling of the cooking chamber (2) is provided, which is adapted and adapted to direct fresh air (9) in the cooking chamber (2). Cooking appliance (1) according to claim 1,
characterized,
that the fan (20) is designed as a radial blower (12). Cooking appliance (1) according to one of the preceding claims,
characterized,
that the fan (20) is infinitely variable and in particular designed as a DC fan (14). Cooking appliance according to one of the preceding claims,
characterized,
that a control device (5) is provided. Cooking appliance (1) according to one of the preceding claims,
characterized,
that a seal (15) between the blower (20) and the cooking chamber (2) is provided. Cooking appliance (1) according to claim 5,
characterized,
in that the seal (15) is designed as a flap device (16) which is particularly suitable and oriented to be opened by the air flow (17) of the blower (20). Cooking appliance (1) according to claim 5,
characterized,
that the seal (15) as an electronically controllable valve device (18) is executed. Cooking appliance (1) according to one of the preceding claims,
characterized,
in that the fan (20) is suitable and designed to be used as garland dehumidification. Cooking appliance (1) according to one of the preceding claims,
characterized,
in that at least one connecting channel (19) is provided between the blower (20) and the cooking chamber (2). Cooking appliance according to one of the preceding claims,
characterized,
that an opening (21) is provided which is adapted and designed to derive air (8) from the cooking chamber (2). Cooking appliance (1) according to claim 10,
characterized,
that the opening (21) in the lower region of the cooking chamber (4) is arranged. Cooking appliance (1) according to claim 10,
characterized,
that the opening with a closure device (22) is automatically closed. Cooking appliance (1) according to claim 11,
characterized,
that the closure device (22) includes the cooking chamber (4), which is adapted and designed to be automatically opened at least one gap (7). Method for operating a cooking appliance (1) with at least one thermally heated cooking chamber (2), with at least one door (4) closing the cooking chamber (2) and with at least one fan (20) arranged outside the cooking chamber,
characterized,
that the fan (20) fresh air (9) into the cooking chamber (2) blows to quickly cool it. Method for operating a cooking appliance according to claim 13,
characterized,
that the opening (21) to support the cooling automatically at least one gap (7) is opened wide. Method according to claim 13,
characterized,
that the fan (20) is started at least for a short time before each opening of the cooking chamber door (4) in order to prevent the jerky escape of hot steam.

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