Patent Description:
In a conventional induction cooking hob the outlet holes for an air stream are arranged at the front side of said induction cooking hob. Said air stream is provided for cooling purposes, in particular for cooling the circuitry. The air stream exiting the induction cooking hob through the outlet holes has a relative high temperature and reaches an area in front of said induction cooking hob. Usually, the user stands in front of the induction cooking hob and is exposed to the hot air stream. A protection shield is often attached in front of the induction cooking hob in order to avoid the hot air stream reaches the user.

<CIT> discloses an induction cooking hob comprising an induction module comprising a module casing and a fan and a cooling element arranged within an inner space of the module casing. <CIT> also discloses means for directing an air stream within the module casing and from the cooling element to a laterally arranged exhaust port.

<CIT> discloses another induction cooking hob being provided with means for creating a flow of air towards and to induction coils and out of the induction cooking hob through a lateral exhaust port.

It is an object of the present invention to provide an induction cooking hob, which avoids that the air stream provided for cooling purposes reaches the user.

The object is achieved by the induction cooking hob according to claim <NUM>.

According to the present invention an induction cooking hob with a cooling system is provided, wherein:.

The present invention allows that the air stream leaves the induction cooking hob through the lateral outlet holes and avoids that the hot air stream reaches the user standing in front of said induction cooking hob. A protection shield at the induction cooking hob is not required.

Furthermore, according to the present invention,.

Moreover, according to the present invention, each induction module is spaced from the front wall, so that the front channel is formed between the induction modules and the front wall.

Additionally, the induction cooking hob comprises two induction modules arranged side-by-side. A first air guide is arranged in front of the cooling element of the induction module on a first side, while a second air guide is arranged in front of the cooling element of the induction module on a second side, and wherein the first air guide deflects the air stream to the at least one lateral outlet hole of the lateral wall on the first side, while the second air guide deflects the air stream to the at least one lateral outlet hole of the lateral wall on the second side.

Further, the circuitry and the cooling element may be arranged side-by-side in a front portion of the induction module, wherein at least some components of the circuitry are arranged on the cooling element, and wherein preferably at least one rectifier and/or at least one power unit are arranged on said cooling element.

According to embodiments, the induction cooking hob can comprise one cooling element, at least one cooling element, two cooling elements or at least two cooling elements. The or each cooling element can be formed as a single-piece or by multiple pieces. A cooling element which is formed as a single-piece can provide a good cooling performance. On the other hand, a cooling element which is made from multiple pieces can be advantageous, as it can increase the flexibility for inserting the cooling element with respect to the degrees of freedom of the arrangement as well as the flexibility regarding the space requirement. In an embodiment, the induction cooking hob comprises two or more induction modules, whereas the cooling system comprises two or more cooling elements which are arranged within or adjacent to the two or more induction modules.

Moreover, the cooling fan may be arranged in a rear portion of the induction module and behind the cooling element.

In particular, the cooling element includes a structure that an air stream generated by the cooling fan penetrates or passes said cooling element and reaches the front channel.

Preferably, at least one of the lateral walls includes a plurality of lateral outlet holes arranged in the front portion of said lateral wall.

Further, the air guide may be formed as a vertical sheet element, wherein preferably said air guide is made of metal and/or plastics.

For example, the air guide is formed as a plane sheet element arranged diagonally inside the front channel and in front of the cooling element.

Moreover, the bottom plate may include at least one lower outlet hole arranged in an outer portion of the front channel, wherein said outer portion is beside the corresponding lateral wall, and wherein preferably a plurality of lower outlet holes is arranged in said outer portion of the front channel.

Additionally, the induction module may be spaced from the closest lateral wall, so that a lateral channel is formed between the induction module and the closest lateral wall. Since the induction module is spaced from the lateral outlet hole, it is not possible that the user touches the circuitry through said lateral outlet holes.

In particular, the bottom plate includes at least one lower outlet hole arranged in a front portion of the lateral channel, wherein preferably a plurality of lower outlet holes is arranged in said front portion of the lateral channel.

Further, the cooling element may include a plurality of cooling fins arranged plane-parallel to each other, wherein a plurality of elongated cooling channels is arranged between said cooling fins, and wherein said elongated cooling channels extend parallel to a connecting line between the cooling fan and the air guide, and wherein preferably the cooling fins extend vertically downwards, so that the elongated cooling channels are formed between the cooling fins and the bottom plate of the casing.

For example, the cooling fan is a radial cooling fan and blows the air stream from the rear to the front, wherein preferably the cooling fan sucks the air at the rear side of the induction cooking hob.

In this case, the induction module on the first side may be spaced from the lateral wall on the first side, while the induction module on the second side may be spaced from the lateral wall on the second side, so that a first and a second lateral channel are formed between the corresponding induction modules and lateral walls.

Additionally, at least one central induction module may be arranged between two lateral induction modules. In this case, the induction cooking hob comprises three or more induction modules arranged side-by-side.

Furthermore, the induction cooking hob comprises a panel, in particular a glass ceramic panel, covering an open top side of the casing.

Moreover, the induction cooking hob comprises at least one induction coil, in particular a plurality of induction coils, electrically connected to the corresponding circuitry.

At last, the at least one induction coil may be arranged between the at least one induction module and the panel.

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

<FIG> illustrates a schematic perspective view of an induction cooking hob according to a preferred embodiment of the present invention.

The induction cooking hob comprises a casing <NUM>. Said casing <NUM> includes a bottom plate <NUM>, a front wall <NUM>, a rear wall <NUM> and two lateral walls <NUM>. The terms "bottom", "front", "rear", "lateral" further prepositions relate to the built-in state of the induction cooking hob. The casing <NUM> includes an open top side covered by a panel, in particular by a glass ceramic panel. Said panel is not shown in <FIG>.

Further, the induction cooking hob comprises two induction modules <NUM>. Said induction modules <NUM> are arranged side-by-side within the casing <NUM>. The induction modules <NUM> are arranged close to the rear wall <NUM>, but spaced from the front wall <NUM> and the corresponding lateral wall <NUM>. Thus, a front channel is formed between the induction modules <NUM> and the front wall <NUM>, while two lateral channels are formed between the induction modules <NUM> and the corresponding lateral wall <NUM>.

Each induction module <NUM> includes a circuitry <NUM>, one or at least one cooling element <NUM> and a cooling fan <NUM>. Each cooling element <NUM> can be made from one piece or from several pieces.

In the embodiment, the induction cooking hob comprises two or at least two cooling elements <NUM>. If one or each cooling element <NUM> is made from a single piece, the cooling performance is increased, as the heat conductance is improved. On the other hand, if a or each cooling element <NUM> is made from several or multiple pieces, the flexibility of arranging the cooling element is increased and the arrangement within the available space can be optimised.

The circuitry <NUM> and the cooling element <NUM> are arranged side-by-side in a front portion of the induction module <NUM>, while the cooling fan <NUM> is arranged behind the cooling element <NUM>. On the output side the circuitry <NUM> is electrically connected to one or more induction coils. The induction coils are arranged above the induction modules <NUM> and beneath the panel. The induction coils are not shown in <FIG>. The circuitry <NUM> is mechanically and thermally coupled to the cooling element <NUM>, so that heat is conducted from the circuitry <NUM> to the cooling element <NUM>. The cooling element <NUM> includes a plurality of cooling fins arranged plane-parallel to each other. A plurality of cooling channels is arranged between the cooling fins. In this example, the cooling fins extend vertically downwards, i.e. the open ends of said cooling fins form the bottom of the cooling element <NUM>. The cooling elements <NUM> are elongated and extend from the cooling fan <NUM> to the front channel.

The circuitry <NUM> comprises a rectifier <NUM>, one or more power units, filter coils <NUM> and further electric and/or electronic components. In this example, each power unit is formed by a pair of insulated-gate bipolar transistors (IGBT) <NUM>. Alternatively, other power units may be used instead of the IGBT <NUM>.

As shown in <FIG>, the rectifier <NUM> and four pairs of the insulated-gate bipolar transistors <NUM> are directly connected to the cooling element <NUM>. However, a separation layer is usually arranged between the rectifier <NUM> and the insulated-gate bipolar transistors <NUM>, respectively, on the one hand and the cooling element <NUM> on the other hand in order to prevent a direct contact between the components. In this example, the rectifier <NUM> and the four pairs of the insulated-gate bipolar transistors <NUM> are connected to the cooling element <NUM> by screws. The rectifier <NUM> and the insulated-gate bipolar transistors <NUM> require cooling. The rectifier <NUM> is provided for converting an input alternating current voltage into a pulsed direct current voltage. The pair of insulated-gate bipolar transistors <NUM> acts as inverted rectifier and converts said pulsed direct current voltage into an alternating voltage for a corresponding induction coil. Usually, the input alternating current voltage has a frequency between <NUM> and <NUM>. In contrast, the frequency of the alternating voltage for the induction coils is between about <NUM> and <NUM>.

The rectifier <NUM> is usually formed as a bridge rectifier circuit and formed by diodes. The rectifier <NUM> and the insulated-gate bipolar transistors <NUM> are so-called power switches. The total electric power is delivered to the rectifier <NUM> and insulated-gate bipolar transistors <NUM>. The total electric power of each induction module <NUM> passes the rectifier <NUM>. Each pair of insulated-gate bipolar transistors <NUM> is provided with a part of said total electric power. For example, up to about <NUM> % of the total electric power is delivered to one pair of insulated-gate bipolar transistors <NUM>. Thus, the rectifier <NUM> and the insulated-gate bipolar transistors <NUM> generate a lot of heat.

In this example, the cooling element <NUM> is elongated, wherein the rectifier <NUM> and the insulated-gate bipolar transistors <NUM> are arranged in series along a longitudinal axis of said cooling element <NUM>. The rectifier <NUM> and the insulated-gate bipolar transistors <NUM> are attached on a sloped cooling surface of the cooling element <NUM>, wherein said sloped cooling surface forms a transition between a top surface and a lateral surface of the cooling element <NUM>. The cooling fins extend along the longitudinal axis of the cooling element <NUM>. An air stream <NUM> generated by the cooling fan <NUM> passes the cooling element <NUM> along its longitudinal axis. The air stream <NUM> passes successively the rectifier <NUM> and each of the insulated-gate bipolar transistors <NUM>. The rectifier <NUM> or one insulated-gate bipolar transistor <NUM> may also use the sloped cooling surface beneath the neighboured insulated-gate bipolar transistors <NUM>, which is advantageous, since the insulated-gate bipolar transistors <NUM> are usually stressed by different powers.

In this example, the cooling element <NUM> is formed as a single-piece part. Alternatively, the cooling element <NUM> may be multipart. The cooling element <NUM> formed as single-piece part allows an efficient heat transfer. The cooling fins provide an extended surface within the cooling element <NUM>, which contributes to the efficient heat transfer. Further, the cooling element <NUM> is relatively flat. The elongated and flat cooling element <NUM> requires only little space within the casing <NUM> of the induction cooking hob.

Moreover, the casing <NUM> includes two air guides <NUM>. The air guides <NUM> are formed as vertical sheet elements and arranged in the front channel. The air guides <NUM> are made of metal or plastics. Each air guide <NUM> corresponds with one of the induction modules <NUM>. The air guides <NUM> are arranged diagonally respective to the cooling fins of the cooling element <NUM> and to the front channel. Each air guide <NUM> is arranged in front of the corresponding cooling element <NUM>.

Furthermore, each lateral wall <NUM> of the casing <NUM> includes a plurality of lateral outlet holes <NUM>. Said lateral outlet holes <NUM> are arranged in the front portions of the lateral walls <NUM>. A plurality of lower outlet holes <NUM> is formed in the bottom plate <NUM> of the casing <NUM>. Said lower outlet holes <NUM> are arranged in the front portions of the lateral channel between the induction module <NUM> and the adjacent lateral wall <NUM>. The lower outlet holes <NUM> are arranged beneath and beside the lateral outlet holes <NUM>.

<FIG> illustrates a schematic top view of the induction cooking hob according to the preferred embodiment of the present invention.

The induction cooking hob comprises the casing <NUM> including the bottom plate <NUM>, the front wall <NUM>, the rear wall <NUM> and the both lateral walls <NUM>. The open top side of the casing <NUM> is covered by the panel, which is not shown in <FIG>. The both induction modules <NUM> are arranged side-by-side within the casing <NUM>. The induction modules <NUM> are arranged close to the rear wall <NUM> of the casing <NUM>. The induction modules <NUM> are spaced from the front wall <NUM> and the corresponding lateral wall <NUM> of the casing <NUM>. The front channel is formed between the induction modules <NUM> and the front wall <NUM> of the casing <NUM>. The both lateral channels are formed between the induction modules <NUM> and the corresponding lateral wall <NUM> of the casing <NUM>.

The induction modules <NUM> include the circuitry <NUM>, the cooling element <NUM> and the cooling fan <NUM> in each case. The circuitry <NUM> and the cooling element <NUM> are arranged side-by-side in the front portion of the induction module <NUM>. The cooling fan <NUM> is arranged behind the cooling element <NUM>. On the output side the circuitry <NUM> is electrically connected to the at least one induction coil. The induction coils are arranged above the induction modules <NUM> and beneath the panel. The induction coils are not shown in <FIG>. The circuitry <NUM> and the cooling element <NUM> are mechanically and thermally coupled to each other. Thus, heat is conducted from the circuitry <NUM> to the cooling element <NUM>. The cooling element <NUM> is elongated and extends from the cooling fan <NUM> to the front channel.

The air guides <NUM> are formed as vertical sheet elements and arranged in the front channel between the induction modules <NUM> and the front walls <NUM>. One of the air guides <NUM> corresponds with one of the induction modules <NUM>. The air guides <NUM> are arranged diagonally relative to the cooling fins of the cooling element <NUM> and to the front channel. The air guide <NUM> is arranged in front of the corresponding cooling element <NUM>.

The lateral outlet holes <NUM> are arranged in the front portions of the lateral walls <NUM>. The lower outlet holes <NUM> are formed in the bottom plate <NUM> of the casing <NUM>, wherein said lower outlet holes <NUM> are arranged in the front portions of the lateral channel between the induction module <NUM> and the adjacent lateral wall <NUM>. Further, the lower outlet holes <NUM> are arranged beneath and beside the lateral outlet holes <NUM>.

The cooling fan <NUM> is a radial cooling fan and generates the air stream <NUM>. The cooling fan <NUM> sucks air in a rear portion of the casing <NUM> and blows the air stream <NUM> horizontally from the rear to the front. Said air stream <NUM> enters the cooling channels formed between the cooling fins of the cooling element <NUM>. Within the cooling element <NUM> the air stream <NUM> flows from the rear to the front. After the air stream <NUM> has left the cooling element <NUM>, the air guide <NUM> deflects the air stream <NUM>. Then, the air stream <NUM> flows along the front channel and against the lateral wall <NUM> of the casing <NUM>. On the left hand side of <FIG>, the air stream <NUM> flows from right to left within the corresponding front channel. In a similar way, the air stream <NUM> flows from left to right within the corresponding front channel on the right hand side of <FIG>. At last, the air stream <NUM> leaves the casing <NUM> through the lateral outlet holes <NUM> and lower outlet holes <NUM>.

The cooling fan <NUM> is an active component, while the cooling element <NUM> is a passive component. The combination of the active cooling fan <NUM> and the passive cooling element <NUM> provides an efficient cooling effect, since the cooling fan <NUM> delivers a big amount of cooling air through the cooling element <NUM>. The cooling air removes permanently heat from the rectifier <NUM> and the insulated-gate bipolar transistors <NUM>.

In this example, the induction cooking hob comprises two induction modules <NUM>. In general, the induction cooking hob according to the present invention comprises two or more induction modules <NUM>. According to a further example, the induction cooking hob may comprise three or more induction modules <NUM> arranged side-by-side. The induction modules <NUM> allow the preparation of different induction cooking hobs.

The induction cooking hob according to the present invention avoids that the air stream provided for cooling purposes reaches the user. A protection shield at the induction cooking hob is not required. Since the induction modules <NUM> are spaced from the lateral outlet holes <NUM>, it is not possible that the user touches the circuitry <NUM> through said lateral outlet holes <NUM>.

Claim 1:
An induction cooking hob with a cooling system, wherein:
- the induction cooking hob comprises a casing (<NUM>) and at least one induction module (<NUM>), and
- the casing (<NUM>) includes at least one air guide (<NUM>) arranged inside a front channel, so that an air stream (<NUM>) from a cooling element (<NUM>) is deflected and guided to at least one lateral outlet hole (<NUM>) of a closest lateral wall (<NUM>),
- the casing (<NUM>) includes a bottom plate (<NUM>), a front wall (<NUM>), a rear wall (<NUM>) and two lateral walls (<NUM>),
- the at least one lateral outlet hole (<NUM>) is arranged in a front portion of the lateral wall (<NUM>), and
- each induction module (<NUM>) is arranged inside the casing (<NUM>),
characterised in that
the induction cooking hop comprises two induction modules (<NUM>) arranged side-by-side;
each induction module (<NUM>) is spaced from the front wall (<NUM>), so that the front channel is formed between the induction module (<NUM>) and the front wall (<NUM>);
wherein each induction module (<NUM>) includes a circuitry (<NUM>), a cooling element (<NUM>) and at least one cooling fan (<NUM>) ;
wherein a first air guide (<NUM>) is arranged in front of the cooling element (<NUM>) of the induction module (<NUM>) on a first side, while a second air guide (<NUM>) is arranged in front of the cooling element (<NUM>) of the induction module (<NUM>) on a second side, and wherein the first air guide (<NUM>) deflects the air stream (<NUM>) to the at least one lateral outlet hole (<NUM>) of the lateral wall (<NUM>) on the first side, while the right air guide (<NUM>) deflects the air stream (<NUM>) to the at least one lateral outlet hole (<NUM>) of the lateral wall (<NUM>) on the second side.