Microwave oven with internal ventilation

0001The present invention relates to the internal ventilation of a Recessed microwave oven comprising an outer housing to be inserted in a recess located in a cabinet kitchen room.

0002More specifically, the invention proposes to achieve internal ventilation the enclosure, in areas ventilate this chamber being of two types: the areas to be cooled on the one hand and the areas to be drained on the other. Areas cooling are all electrical or electronic components, by Joule effect, generate heat. The areas are dry those present inside the cooking cavity, ie, en particulier, la porte et les parois de cette cavité sur lesquelles the water vapor emitted during the heating of food by microwaves, tends to condense.

0003It is necessary to provide an air flow within the oven and, of course, input and output ports of the air.

0004known microwave ovens have, for many of them, at least one of these orifices located on a face other than the face before. This requires to make a recess forming a space natural air circulation and to reduce input and air outlets in the front plan before the oven or to provide a fireplace on the back of the housing unit. The patent application US4332993 in turn discloses a device which positioned on the inlet and air outlet arranged on the top of the oven and which, by the presence of a turbine, provides the entry and the output of the air in the enclosure of said oven.

0005Such systems all have the following constraint: it must provide a recessed niche in higher dimensions overall dimensions of the device.

0006A common constraint of these devices, particularly if we want a niche to the smallest possible dimensions, is the necessary presence of a vent stack in furniture kitchen room.

0007The object of the invention is to provide a microwave oven Built imposing no constraint on the niche for to receive, it simply presenting the standard dimensions offered by the kitchen furniture manufacturers. The invention and facilitates integration of said furnace in a kitchen. The invention proposes, moreover, to do so economically.

0008According to the invention, the air circuit inside the oven microwave is as follows: air enters through the air inlet located upper region of the front of the oven, above the door, passes through a first technical area being drawn in by the fan, before being divided into two streams at the outlet of fan. The first flows through a second technique and area will dry the door, then the inside of the cooking cavity, before joining a fourth technical area. The second stream passes through a third technical area before joining the fourth zone technical. The two streams are expelled through the air outlet located in lower region of the oven, beneath the door.

0009And ventilating the entire interior of the furnace is ensured.

0010We distinguish a first technical area, which is placed the control electronics and ideally electronics power. According to the invention, this zone comprised between the inlet air and fan, a slight depression and bathed by air Arriving fresh ambience of the room.

0011The magnetron placed, according to a preferred feature of the invention, in the second technical area, cools heating the flux which passes through it before being introduced into the cooking cavity, allowing the heated air to increase its water removal capacity of the cooking cavity and to heat the door and walls of said cavity to prevent condensation.

0012Finally, the magnetron power, ideally placed in a third technical area and preferentially in the part Lowest this zone, is cooled by the third stream, while advantageously being positioned in the lower part of the furnace. This positioning the lower part facilitates the design of the apparatus, said power supply being a high body mass and therefore binding structure.

0013In addition, an interesting consequence of this device is it allows use of a fan comprising an economic one motor driving two turbines.

0014According to a particularly advantageous characteristic of the invention, the steam which escapes from the heated food and which has a natural tendency to rise once it is no longer imposed in a circuit, leaves the lower part of the oven. thus it has time to become diluted in the air before risking deposit on the wall of the unit immediately above the furnace. this allows to preserve the aesthetic and functional qualities of said cabinet.

0015In a preferred embodiment of the invention, the output of first stream which has passed through the cooking cavity takes place in the upper part thereof. This stream then descends by a fifth technical area between the side walls of the enclosure and the cavity before finding the second stream in the fourth zone technical. This gives him time to cool before expelled outside the furnace.

0016Other features and advantages of the invention apparent from the description which follows, given as an example non-limiting, with reference to the accompanying drawings in which:<ul><li>Figure 1 is a perspective view of a microwave oven according to the invention; </li><li>Figure 2 is a similar view to that of Figure 1 and illustrates more specifically the area 4a and how the air flows in said zone;</li><li>Figure 3 is a view similar to that of Figure 1 and illustrates more specifically the area and 4b how the air flows in said zone;</li><li>Figure 4 is a view similar to that of Figure 1 and illustrates more specifically the area 4c and how the air flows in said zone;</li><li>Figure 5 is a view similar to that of Figure 1 and illustrates more particularly the zone 4d and how the air flows in said zone; and</li><li>Figure 6 is a view similar to that of Figure 1 and illustrates more specifically the fourth area and how the air flows in said area.</li></ul>

0017In Figure 1 there is shown a perspective view of an oven microwave oven according to the invention. From this view, in particular, visualize the components that will occur in the following description. Of course, many components such those participating in the training tray from the oven or at its lighting are not shown or described here as they do different not well known devices of skill in the art and present on existing furnaces.

0018Figures 1 and 2 illustrate the air flow in the technical area 4a.

0019According to the invention, thanks to the suction fan 11, air enters the zone 4a through the openings 5 ​​located in front of the oven, between the front door 3 and the control panel 8. It cools electronic components 7 which are located behind the headband control and / or at other locations within said area 4a. Then it enters one of the two turbines 11b or 11c of the fan, said turbines are both driven in rotation by the motor 11a.

0020Thus, according to the invention, the technical area 4a is depressed through the suction provided by the blower 11.

0021The fact that the fan 11 is formed of a motor 11a and two turbines 11b and 11c is very advantageous from an economic standpoint. However it can be envisaged to replace it with two fans to a single turbine without departing from the scope of the invention.

0022Figures 1 and 3 illustrate the air flow in the technical area 4b.

0023According to the invention, the technical area 4b is formed of a first air guide 12, the magnetron 9 and a second air guide 13. This technical zone 4b is bathed by the stream b from turbine 11b. The first air guide 12 directs the flow to the overpressure magnetron 9. indication, inside the air guide 12, air is at a temperature in the range of 35 to 55 ° C and preferably equal to 45 ° C. Said magnetron 9 is traversed and thereby cooled by the stream b. The flow is then directed to b the front of the furnace through the air guide 13 which communicates with the cavity cooking 2 via inlet openings (not shown) in the sheet forming the top wall of the cooking cavity 2, said inlet openings being located right above the door 3. The b flow is being heated by passing through the magnetron 9, he won about 40 ° C, then being in a temperature range between 75 and 95 ° C, it has, interestingly, increased its minimum heating and drying from inside of the door 3 and the cooking cavity elements 2 in order to avoid condensation.

0024Figures 1 and 4 illustrate the air flow 4c in the technical area.

0025According to the invention, the turbine 11c breath flow directly c on the power supply 10 of the magnetron 9, which is one of the elements present in the technical area 4c to cool, in compliance with standards, while ensuring a good ability to function. Other components may be present in this technical area 4c, but they are not directly affected by this invention and have therefore not been shown.

0026According to a preferred feature of the invention, supply 10 of magnetron 9 is in the lower part of the Technical area 4c and thus in the lower part of the furnace. This position is particularly advantageous for economic reasons. In Indeed, in this position, power 10 of the magnetron 9 directly attached to the bottom of the furnace and it is not necessary to providing a reinforced area to greet and this could be required if the said 10 of the magnetron power was 9 placed in height.

0027The technical area is separated 4c technical areas 4d and 4e by a perforated wall 14 whose main role is to maintain cavity 2 in position. The number and position of openings 15 present in this wall may be varied without departing from the scope of the invention, as long as it is provided at least one opening 15 allowing the flow c joining the technical area 4^e, is directly or through the technical area 4d.

0028Figures 1 and 5 illustrate the air flow in the zone 4d.

0029In a preferred embodiment of the invention, the stream b spring of the cooking cavity 2 through outlet openings (not shown) located in the upper part of the cavity cook 2, said outlet openings may be on the top wall of the cooking cavity 2, or in the part upper vertical walls of the cooking cavity 2.

0030Once out of the cooking cavity 2, the flow is guided b 4d to the technical area which is located on one side of the furnace, or preferably, on both sides thereof.

0031According to the invention, the stream b then joined below the furnace to the fourth technical area.

0032Figures 1 and 6 illustrate the air flow in the fourth area.

0033According to the invention, flows b and c converge in the area Technical 4th before exiting the furnace through openings positioned 6 in the lower part of the front of the furnace, below the 3 door.

0034It is possible, within the scope of the invention in the number and disposition of the openings 15 and pressure ratios of flows b and c, that the mixture of stream b and c begins in the border areas between technical areas 4c and 4d. This does not affect the effectiveness of the ventilation realized. Indeed, once in the 4d technical area, flow b is more utility and its temperature may be arbitrary. As for the flow c it is blown directly on the magnetron 10 supply 9 and creates a movement of air to the immediate vicinity of the feed 10 of magnetron 9, preventing the parasites flow arrival the temperature could be greater than that of said stream c. The conditions for good operation are not affected by possible uncontrolled of the mixing zone flows b and c.

0035It is equally possible, without exceeding the scope of the invention, the flows b and c are fully channeled into outlet openings 6 dedicated to each flow, and that thereby they do not mix within the chamber 1 of the furnace.

0036According to one embodiment of the invention, the power supply 10 magnetron 9 is a high voltage transformer. Equally possible whether a switching power supply or "inverter".

0037Similarly, it is also possible in another mode embodiment of the invention that the air inlet 5 is always the upper part of the oven front, but above the headband 8 control or it is separated into several openings located around the control panel 8.

0038An interesting result is that a furnace according to the invention This preserves the furniture around said oven. Indeed, moist exhaust air at the air outlet 6 will not go directly touch the furniture located above the niche Recessed oven. He will have time to become diluted and therefore posing a lower moisture content prior to contact with colder surfaces and likely to fear moisture.

0039Another interesting consequence of the invention is that the fan 11 located relatively far from the air outlet 6, the speed of the air exiting the furnace is not very high and this that limits the risk of discomfort for the user standing before the oven. The user feels less strong air current that if the ventilator was in the immediate vicinity of the outlet. Of Moreover, again thanks to the relatively large distance traveled the flow inside the chamber 1, the air outlet is at a temperature substantially lower than that found in general the output of this type. The air expelled from the oven according the invention has a temperature within a range between 35 and 55 ° C and ideally close to 45 ° C.

0040The features described above are those of an oven Microwave cooking only use this means, but the invention can also be applied to a furnace having, in addition to the mode cooking by microwave, other cooking modes operable alone or in combination, such as a grill mode (direct heating through an armored resistance, quartz or halogen) or a heat method rotating (injection into the cavity through a fan, air heated by an armored resistance).

0041The invention meets the need to achieve an internal ventilation a built-in microwave oven, a simple, efficient and Economic and allowing installation in any recess integrated kitchen with standard dimensions without him impose in said niche specific areas to ensure the air circulation and this in the best respect of the furniture surrounding and comfort of the user.