Patent Description:
Today there are cooking ovens having different functions, for example a microwave heating function, a steam cooking function and/or a pyrolytic cleaning function. For each function special components are required. Further, most of said components must be cooled down.

Documents <CIT> and <CIT> relate to cooking ovens and evacuation of cooking fumes from the cooking chamber.

For example, a magnetron for the microwave heating function requires an active cooling with a specific flow rate. Therefore, a cooling fan blows an air stream directly or via a duct to the magnetron.

Further, in a cooking oven with pyrolytic cleaning function the housing, the oven door and the electronic circuits are usually kept cool by a double-channel cooling system for safety and functionality reasons. For example, said double-channel cooling system is driven by a double-inlet centrifugal fan. The one inlet is connected to a suction channel extending to the oven door and cavity exhaust, wherein sucked air keeps the oven door cool on the one hand and evacuates moist air from the cavity on the other hand. The other inlet is open, wherein air from the space around the component carrier is sucked for cooling the housing and electronic elements. The outlet of the centrifugal fan is connected to a blowing channel through which the air is blown out of the cooling system.

A cooking oven with microwave heating function and pyrolytic cleaning function comprises usually two cooling fans. The one cooling fan is provided for cooling the magnetron, while the other cooling fan drives the double-channel cooling system for cooling the oven door, the housing and the electronic elements. However, this concept is complex and expensive, since two cooling fans are required.

It is an object of the present invention to provide a cooling system for a cooking oven, which allows the cooling of components for different functions by low complexity and costs.

The object is achieved by the cooling system for a cooking oven according to claim <NUM>.

According to the present invention a cooking oven according to claim <NUM> is provided.

The main idea of the present invention is the subdivided inlet of the cooling fan. The first inlet portion can suck air either from the space above or beside the oven cavity, e.g. for cooling down electronic components and the housing, or from the magnetron air duct, e.g. for cooling down the magnetron. In contrast, the second inlet portion always sucks air from the space above or beside the oven cavity for cooling down the electronic components and the housing. If the magnetron air duct is connected to the first inlet portion, then the space above or beside the oven cavity on the one hand and a magnetron connected to said magnetron air duct on the other hand are simultaneously cooled by only one cooling fan. This results in low complexity of the cooling system. In addition, an inverter power supply for the magnetron can be effectively cooled by arranging the inverter besides the magnetron in a region from where air is effectively sucked by the cooling fan into the magnetron via the magnetron air duct and the top fan inlet. Further, said cooling system is suitable for cooking ovens within and without microwave heating function. In the latter case, the same cooling system without the microwave duct may be used. This increases the usability of the cooling system and makes said cooling system modular.

For example, the cooling system is arranged above the oven cavity of the cooking oven. Alternatively, the cooling system is arranged at a side wall or in another portion of said oven cavity.

Preferably, the cooling fan is a double-inlet centrifugal fan. The one inlet of the fan is a sub-divided one as mentioned above. The further inlet is connected to the suction air channel connected to the cavity for evacuating moist air, i.e. cavity exhaust. Further, the further inlet is connected to air inlet slots in the front of the oven. Said air inlet slots may be opened or closed depending on if door cooling is required or not, respectively. For example, a cooking oven with pyrolytic function usually requires the door cooling. In this case, the air inlet slots in the front of the oven are opened and aligned with the openings in an oven door through which the air is sucked for cooling said oven door. If door ventilation is not required, then the air inlet slots are closed, and the suction air channel works purely for cavity exhaust.

Further, an outlet of the blowing air channel may be arranged at or connected to an outer space of the cooking oven.

For example, the outlet of the blowing air channel is arranged at the front side of the cooking oven.

The outlet of the blowing channel may be formed as a horizontal slot.

Preferably, the outlet of the blowing air channel is arranged above the oven door.

Further, an inlet of the magnetron air duct may be connected or connectable to a magnetron, wherein preferably said magnetron is arranged or arrangeable at the outer side of the oven cavity of the cooking oven.

Moreover, at least one air inlet slot of the suction air channel may be arranged in a front frame of the oven cavity.

Preferably, the at least one air inlet slot is aligned with a door outlet slot of the oven door in a closed state of said oven door.

According to the preferred embodiment, the inlet of the cooling fan subdivided into the first inlet portion and the second inlet portion is a top fan inlet arranged on the top of said cooling fan, while the further inlet of the cooling fan connected to the suction air channel is a bottom fan inlet arranged at the bottom of said cooling fan.

According to a preferred embodiment, the cooling system is arranged or arrangeable above the oven cavity of the cooking oven. Alternatively, the cooling system may be arranged or arrangeable besides or beneath the oven cavity of the cooking oven.

Further, the present invention relates to a cooking oven with a microwave heating function, a steam cooking function and/or a pyrolytic cleaning function, wherein said cooking oven comprises the cooling system mentioned above.

At last, the cooking oven includes the microwave heating function, wherein the magnetron and the magnetron duct are detachably arranged at said cooking oven. Two different embodiments of the cooking oven may be manufactured by low complexity and costs.

The present invention will be described in further detail with reference to the drawing, in which.

<FIG> illustrates a schematic perspective top view of a cooking oven <NUM> with a cooling system according to a preferred embodiment of the present invention.

The cooking oven <NUM> comprises an oven cavity <NUM>, an oven door <NUM>, a magnetron <NUM>, a transformer <NUM> and the cooling system. The magnetron <NUM>, the transformer <NUM> and the cooling system are arranged on the top of the oven cavity <NUM>. The transformer <NUM> is provided for supplying the magnetron <NUM>. The cooling system includes a blowing air channel <NUM>, a suction air channel <NUM>, a magnetron air duct <NUM>, a motor <NUM> and a cooling fan <NUM>. The cooling fan <NUM> is arranged within the blowing channel <NUM>, wherein a top fan inlet <NUM> of said cooling fan <NUM> is formed in the top side of the blowing channel <NUM>. The motor <NUM> is provided for driving the cooling fan <NUM>. The suction air channel <NUM> is arranged beneath the blowing air channel <NUM>.

In this example, the outlet of the blowing channel <NUM> is formed as a flat and wide horizontal slot. Thus, the height of the blowing channel <NUM> decreases from the top fan inlet <NUM> to the outlet, while the width of said blowing channel <NUM> increases from the top fan inlet <NUM> to the outlet. The magnetron duct <NUM> extends from the magnetron <NUM> to the top fan inlet <NUM>.

<FIG> illustrates two perspective views of the magnetron air duct <NUM> of the cooling system according to the preferred embodiment of the present invention.

The magnetron air duct <NUM> is formed as a hollow part. The magnetron air duct <NUM> connects the top fan inlet <NUM> of the cooling fan <NUM> to the magnetron <NUM>. Air is sucked through the magnetron <NUM> via the magnetron air duct <NUM> in order to cool down said magnetron <NUM>.

For example, the magnetron air duct <NUM> is elongated, wherein an inlet <NUM> and an outlet <NUM> are arranged at its both ends, respectively. In this example, the inlet <NUM> and the outlet <NUM> are directed perpendicular to the longitudinal axis of the magnetron air duct <NUM>, wherein the inlet <NUM> and the outlet <NUM> are directed perpendicular to each other.

<FIG> illustrates a schematic perspective view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention.

The cooking oven <NUM> comprises the oven cavity <NUM> and the oven door <NUM>. The magnetron <NUM>, the transformer <NUM> and the cooling system are arranged on the top of the oven cavity <NUM>. The blowing air channel <NUM> extends from the top fan inlet <NUM> to a front side of the cooking oven <NUM>. The magnetron air duct <NUM> extends from the magnetron <NUM> to the top fan inlet <NUM>.

Air from the magnetron <NUM> is sucked through the magnetron air duct <NUM> to the top fan inlet <NUM> by the cooling fan <NUM>. Further, air from the space above the oven cavity <NUM> is sucked through the top fan inlet <NUM> and into the blowing channel <NUM> and blown through said blowing channel <NUM> to the area in front of the cooking oven <NUM> by the cooling fan <NUM>. Thus, electronic elements and other components arranged above the oven cavity <NUM> are cooled by the cooling fan <NUM>.

<FIG> illustrates a schematic top view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention. For reasons of clarity, the magnetron duct <NUM> is not shown in <FIG>.

The top fan inlet <NUM> of the cooling fan <NUM> is subdivided into a first inlet portion <NUM> and a second inlet portion <NUM>. The first inlet portion <NUM> is connected to the outlet <NUM> of the magnetron air duct <NUM>, while the second inlet portion <NUM> remains open. The air from the magnetron <NUM> is sucked through the magnetron air duct <NUM> and through the first inlet portion <NUM> into the blowing channel <NUM> by the cooling fan <NUM>. The air from the space above the oven cavity <NUM> is sucked through the second inlet portion <NUM> into the blowing air channel <NUM> by the cooling fan <NUM> and then blown out through said blowing channel <NUM> to the area in front of the cooking oven <NUM>.

<FIG> illustrates a schematic perspective view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention. <FIG> clarifies that the first inlet portion <NUM> is covered by the magnetron air duct <NUM>, while the second inlet portion <NUM> remains open. The first inlet portion <NUM> is connected to the outlet <NUM> of the magnetron air duct <NUM>.

Preferably, the cooling system in <FIG> is suitable for a cooking oven with microwave heating function, steam cooking function and pyrolytic cleaning function.

<FIG> illustrates a schematic sectional side view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention. <FIG> clarifies the arrangements of the blowing channel <NUM> and the magnetron air duct <NUM>. The blowing channel <NUM> encloses the cooling fan <NUM>, while the outlet <NUM> of the magnetron air duct <NUM> is arranged above the first inlet portion <NUM>.

The air stream from the magnetron <NUM> flows horizontally through the magnetron air duct <NUM>. Then, said air stream is sucked downwards through the outlet <NUM> of the magnetron air duct <NUM> and through the first inlet portion <NUM> by the cooling fan <NUM>.

<FIG> illustrates a schematic partial sectional side view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention.

<FIG> clarifies the arrangement of the blowing air channel <NUM> and the suction air channel <NUM>. The suction air channel <NUM> is arranged beneath the blowing air channel <NUM>. The blowing air channel <NUM> is interconnected between the cooling fan <NUM> and the air outlet slot <NUM> arranged above the oven door <NUM>. The suction air channel <NUM> is connected between the cooling fan <NUM> and the air inlet slot <NUM>. The air inlet slot <NUM> is aligned with a door outlet slot <NUM> of the oven door <NUM> in a closed state of said oven door <NUM>. By this way, the suction air channel <NUM> is connected to the interior of the oven door <NUM> in order to cool down said oven door <NUM>. In this example, the interior of the oven door <NUM> is subdivided into three vertical channels arranged between an outer panel, an inner panel and two intermediate panels. Further, the suction air channel <NUM> is connected to the oven cavity <NUM> in order to evacuate moist air, i.e. cavity exhaust.

<FIG> illustrates a schematic partial perspective view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention.

<FIG> clarifies the arrangement of the air outlet slot <NUM> and the air inlet slot <NUM>. The air outlet slot <NUM> is arranged above the oven door <NUM> and above the front opening of the oven cavity <NUM>. The air inlet slot <NUM> is arranged in a front frame enclosing said front opening of the oven cavity <NUM>. In this example, the air inlet slot <NUM> is subdivided into three serial slots. The suction air channel <NUM> is connected to the air inlet slot <NUM>. The air inlet slot <NUM> may be opened or closed depending on if door cooling is needed or not, respectively.

<FIG> illustrates a schematic perspective view of the oven door <NUM> for the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention.

The door outlet slot <NUM> is arranged horizontally in the upper portion of the oven door <NUM>. In this example, the door outlet slot <NUM> is subdivided into three serial slots. In contrast, the door inlet slot <NUM> is arranged horizontally in the lower portion of the oven door <NUM>. The three cooling channels extend from the door inlet slot <NUM> to the door outlet slot <NUM>. Said cooling channels extend between the outer door panel, the inner door panel and the both intermediate door panels arranged between said outer and inner door panels.

For example, a cooking oven with pyrolytic function usually requires a door cooling. In this case, the air inlet slots in the front of the oven are opened and aligned with the openings in the door through which the air is sucked to cool the door. If the door ventilation is not required, then the air inlet slots <NUM> are closed and the air suction channel works purely for cavity exhaust.

<FIG> illustrates a schematic partial sectional perspective view of the cooking oven <NUM> with the cooling system according to the preferred embodiment of the present invention.

In this example, the cooling fan <NUM> is a double-inlet centrifugal fan. The cooling fan <NUM> comprises the top fan inlet <NUM> and the bottom fan inlet <NUM>. The top fan inlet <NUM> is sub-divided into the first inlet portion <NUM> and the second inlet portion <NUM>. The first inlet portion <NUM> is connected to the magnetron air duct <NUM>, while the second inlet portion <NUM> is open. The bottom fan inlet <NUM> is connected to the suction air channel <NUM>. The suction air channel <NUM> is connected to the oven cavity <NUM> for evacuating moist air, i.e. cavity exhaust, on the one hand. On the other hand, the suction air channel <NUM> is connected to the interior of the oven door <NUM>. In the closed state of the oven door <NUM>, the door outlet slot <NUM> of said oven door <NUM> is aligned with the air inlet slot <NUM> of the suction air channel <NUM>.

<FIG> illustrates a schematic perspective view of the cooking oven <NUM> with the cooling system according to a first further embodiment of the present invention.

The cooking oven <NUM> in <FIG> is substantially identical with the cooking oven <NUM> in <FIG>. However, the magnetron <NUM>, the magnetron duct <NUM> and the transformer <NUM> lack in <FIG>. The cooking oven <NUM> of the first further embodiment is provided without the microwave heating function. Thus, the present invention allows the provision of at least two different cooking ovens <NUM> by low complexity, wherein the one embodiment includes the microwave heating function, while the first further embodiment lacks the microwave heating function.

Particularly, the cooling system in <FIG> is suitable for a cooking oven with steam cooking function and pyrolytic cleaning function.

<FIG> illustrates a second further embodiment of the present invention in another schematic perspective view of the cooking oven <NUM>.

The cooking oven <NUM> in <FIG> is again substantialy identical with the cooking oven <NUM> in <FIG>. However, in <FIG> the transformer <NUM> is missing. In alternative to the transformer <NUM>, in <FIG> the cooking oven <NUM> is provided with an inverter <NUM> power supply for the magnetron <NUM>, such as is itself known in the prior art. The inverter <NUM> can be favourably adapted to use pulse-width modulation to provide effectively continuous heating, allowing food to be heated more evenly and quickly.

In <FIG> the inverter <NUM> is arranged besides the magnetron <NUM> in a region from where air is effectively sucked by the cooling fan <NUM> into the magnetron <NUM> and via the magnetron air duct <NUM> into the top fan inlet <NUM>. The region where the inverter <NUM> is arranged in <FIG> is also shown in <FIG>, however as an empty region. In <FIG> arrows in the corresponding region indicate the air stream that is sucked into the magnetron <NUM> and that is used for the cooling of the inverter <NUM> in <FIG>.

In the embodiment of the invention shown in <FIG> the arrangement of the inverter <NUM> besides the magnetron <NUM> allows effective cooling of the inverter <NUM> by the air stream that is generated by the cooling fan <NUM>. The air stream that cools the inverter <NUM> enters into the magnetron <NUM> and is led via the inlet <NUM> into the magnetron air duct <NUM> and into the top fan inlet <NUM>. The embodiment shown in <FIG> does not require any air duct that directly connects the inverter <NUM> to the magnetron <NUM> for an effective cooling of the inverter <NUM>. Rather, the inverter <NUM> can be placed without any direct connection to the magnetron <NUM> into the air stream that is sucked into the magnetron <NUM> by the cooling fan <NUM>, wherein the cooling fan <NUM> is connected to the other side of the magnetron <NUM> via the inlet <NUM>, the magnetron air duct <NUM> and the top fan inlet <NUM>.

In a further preferred embodiment also shown in <FIG>, an air guide <NUM> which is formed as a vertical wall can be arranged besides the inverter <NUM>. The air guide <NUM> is oriented essentially in parallel to said air stream shown in <FIG> that enters into the magnetron <NUM>. The air guide <NUM> increases the efficiency of the cooling of the inverter <NUM> by effectively directing the air stream that enters into the magnetron <NUM> over the inverter <NUM>. Thus, the present invention further allows the provision of a cooking oven <NUM> that comprises an inverter <NUM> instead of a transformer <NUM>, wherein the inverter <NUM> is effectively cooled in addition to the magnetron <NUM> with low complexity. The inverter <NUM> is cooled by the air stream that cools already the magnetron <NUM> and that is generated by the cooling fan <NUM> and sucked through the magnetron <NUM> via the magnetron air duct <NUM> into the top fan inlet <NUM>.

Claim 1:
A cooking oven (<NUM>) comprising a cooling system and microwave heating function comprising a magnetron duct, wherein:
- the cooling system is arranged or arrangeable at an outer side of an oven cavity (<NUM>) of the cooking oven (<NUM>),
- the cooling system comprises a cooling fan (<NUM>),
- the cooling system comprises a blowing air channel (<NUM>),
- the cooling system comprises a suction air channel (<NUM>),
- an outlet of the cooling fan (<NUM>) is connected to the blowing air channel (<NUM>),
- an inlet (<NUM>) of the cooling fan (<NUM>) is subdivided into a first inlet portion (<NUM>) and a second inlet portion (<NUM>),
- the first inlet portion (<NUM>) is connected to an outlet (<NUM>) of the magnetron duct (<NUM>), while
- the second inlet portion (<NUM>) is permanently open, and
- a further inlet (<NUM>) of the cooling fan (<NUM>) is connected to the suction air channel (<NUM>).