Abstract
An assembly (10) for detecting operating parameters within an oven cavity (22) comprises: *(a) a housing (12); *(b) a sensor (14, 64) disposed within the housing (12); *(c) an air inlet (16) for feeding air into the housing (12); and *(d) an air outlet (18, 38) through which air can leave the housing (12).
Claims
1. Assembly for detecting operating parameters within an oven cavity, the assembly comprising: (a) a housing; (b) a sensor arranged within the housing; (c) an air inlet for feeding air into the housing; and (d) an air outlet through which air can leave the housing.
2. The assembly of claim 1, further comprising: a heatsink disposed within the housing in contact with the sensor.
3. The assembly of claim 2, further comprising: a thermal interface material disposed between the heatsink and the sensor.
4. The assembly of claim 1, wherein the sensor comprises at least one of an optical sensor, an imaging system, a humidity sensor, a temperature sensor, a gas sensor, a sound sensor, and a chemical sensor.
5. The assembly of claim 1, further comprising a cover which covers a receptive region of the sensor but which is permeable for a physical or chemical parameter to be detected by the sensor.
6. The assembly of claim 5, wherein the sensor is a humidity sensor and the cover comprises a membrane which is permeable for water vapor.
7. The assembly of claim 5, wherein the sensor is an optical sensor and the cover comprises a transparent element.
8. The assembly of claim 7, wherein the transparent element is designed as an optical filter and/or lens.
9. The assembly of claim 1, wherein the housing or parts thereof are made from a material having a thermal conductivity at standard conditions of less than 10 W/m.Math.K.
10. The assembly of claim 1, further comprising a housing support (52) for mounting the housing to a wall of the oven cavity.
11. The assembly of claim 10, wherein the housing support is made of a material having a lower thermal conductivity than the housing.
12. Oven with an oven cavity and the assembly of claim 1, the oven comprising means for generating a forced air flow which is directed to the air inlet, and wherein the assembly is located within the oven cavity.
13. Oven with an oven cavity and the assembly of claim 1, wherein the assembly is mounted to an exterior side of a wall of the oven cavity and communicates with an interior of the oven cavity through a region provided with the wall of the oven cavity which is permeable for a physical or chemical parameter to be detected by the sensor.
14. Oven of claim 12, wherein the housing is formed in part by a deep drawn region in a wall of the oven cavity.
15. Oven of claim 12, wherein the air outlet is located to expel air into the oven cavity.
16. Oven of claim 15, having an assembly as defined in claim 5, wherein the air outlet comprises one or more outlet openings located in a perimeter of the cover.
17. Oven of claim 12, wherein the air outlet is connected to a conduit to remove air from the assembly.
18. Oven of claim 12, wherein the air outlet is located in a wall of the housing so as to expel air to an exterior side of the housing.
19. Oven of claim 12, wherein said means for generating a forced air flow comprise a fan for feeding ambient air to the air inlet 16.
20. Oven of claim 12, further comprising an insulation layer at a wall of the housing facing towards the oven cavity.
21. An oven comprising an oven cavity for cooking food therein, and a sensor assembly, the sensor assembly being attached to or formed in part with a wall of the oven cavity and comprising a sensor housing and a sensor disposed within the sensor housing, said sensor being adapted to detect an operating parameter during a cooking operation within the oven cavity, at least a portion of said sensor housing and/or said oven cavity between said sensor and an interior of said cavity being transparent or permeable to the operating parameter to be detected by the sensor, said sensor housing further comprising an air inlet and an air outlet, means to generate a forced flow of air into said inlet and over said sensor so as to cool said sensor prior to being expelled from the sensor housing via said air outlet, the air outlet configured to discharge said flow of air in turbulent flow, said sensor housing being made of a material having a thermal conductivity less than 1 W/m-K at standard conditions of temperature and pressure, a heatsink in thermal communication with said sensor within the sensor housing and being effective to enhance thermal energy transfer from said sensor into said stream of cooling air passed through said sensor housing, and a layer of insulation at a wall of said housing facing toward the oven cavity.
Description
[0026] Preferred embodiments of the present invention will be described by reference to the drawings in which:
[0027] FIG. 1 shows a sectional view of a first embodiment of a sensor assembly in accordance with the present invention;
[0028] FIG. 2 shows a sectional view of a second embodiment of a sensor assembly in accordance with the present invention;
[0029] FIG. 3 shows a sectional view of a third embodiment of a sensor assembly in accordance with the present invention;
[0030] FIG. 4 is a perspective view of the sensor assembly illustrated in FIG. 2;
[0031] FIG. 5 illustrates an exploded view of a sensor assembly in accordance with the present invention, wherein the sensor is an optical sensor; and
[0032] FIG. 6 illustrates an exploded view of a sensor assembly in accordance with the present invention, wherein the sensor is a humidity sensor.
[0033] FIG. 1 illustrates a sensor assembly made in accordance with the present invention. Sensor assembly 10 comprises a housing 12 in which there is located a sensor element 14, which in the embodiment shown in FIG. 1 comprises an imaging system having a camera. Housing 12 comprises an air inlet 16 for feeding air into the housing 12 and an air outlet 18 through which air can leave the housing 12 upon having passed over and along the sensor element 14 for cooling thereof, as is depicted in FIG. 1 by arrows. To further facilitate heat being withdrawn from sensor element 14, the sensor assembly 10 comprises a heat sink 20 which is mounted on the side of the sensor element 14 facing away from an oven cavity 22, which is formed by an oven muffle of which in FIG. 1 there only is shown a portion of an upper wall 24.
[0034] As shown in FIG. 1, sensor assembly 10 comprises an annular portion 26 protruding from a bottom wall 28 of housing 12, which is mounted within an opening 30 of the upper wall 24 of the oven muffle. To prevent oven fumes from entering the annular portion 26, there is provided a transparent element 32 which enables the sensor element 14 to monitor the interior of the oven cavity 22.
[0035] FIG. 2 shows a sensor assembly which differs from the one illustrated in FIG. 1 in that the air that is passed into the housing 12 via air inlet 16 is expelled into the oven cavity 22. To this end housing 12 comprises a wall 34 that closes the end of the housing 12 opposite air inlet 16, and further comprises an air outlet 36 at the bottom of annular portion 26. As is shown in further detail in the perspective view of FIG. 4, annular portion 26 can be designed as an annular channel, into which air leaving housing 12 enters via a plurality of openings 37 and from which the air is passed into the oven cavity 22 in an annular flow around transparent element 32 via a plurality of outlet openings 38.
[0036] In the embodiment illustrated in FIGS. 2 and 4, the sensor assembly 10 further is designed for use in an oven that in addition to a heating capability, such as by heating elements, hot air or steam, further provides for a microwave function. While the sensor assembly 10 is protected from oven fumes by the transparent element 32, in order to protect the sensor element 14 from microwaves there additionally is provided a metallic wall 39 having an aperture 40 in close proximity to the optical sensor element 14.
[0037] As can be best seen in FIG. 4, the heat sink 20 is provided with a plurality of fins 42 which provide for a large surface area of the heat sink 20 to thus improve the heat exchange with cooling air that is passed through the housing 12.
[0038] In FIG. 3 there is shown a variant of a sensor assembly 10 that is similar to the ones shown in FIGS. 1 and 2, but in which the air leaving housing 12 is expelled laterally from the annular portion 26, so as to be fed into the space between upper wall 24 of the oven muffle and bottom wall 28 of housing 12, so as to provide for additional cooling of housing 12 and further to provide for an insulating air layer between the upper wall 24 of the oven muffle and the bottom wall 28 of the assembly housing 12.
[0039] While in the embodiments shown in FIGS. 1 and 3 the air flow after cooling the sensor is used to provide for further cooling, either of another sensor as in the FIG. 1 embodiment, or another part of the same sensor assembly as in the FIG. 3 embodiment, the air leaving the sensor assembly also can be used to provide a dynamic air barrier, preferably by providing for a turbulent swirling flow, which prevents oven fumes or other dirt particles from reaching the active sensor area.
[0040] Whereas in the embodiments illustrated in FIGS. 1 to 4 at least a portion of the sensor assembly 10 is located behind a wall of the oven muffle, it is to be understood that similarly as is shown for the annular portion 26, also the entire bottom wall 28 could be in direct contact with the interior of the oven cavity 22, such as by arranging assembly 10 in an opening in a wall of the oven muffle (similarly as opening 30), the size of which corresponds to the size of the bottom wall 28. Furthermore, due to the cooling capacity of the sensor assembly also the entire sensor assembly 10 could be arranged within the interior 22 of the oven cavity, such as within a depression of a wall of the oven muffle, which depression may be formed as a deep drawn region of the oven muffle.
[0041] The sensor assembly suggested herein is capable of sufficiently cooling sensors for use within a baking oven, which further to having resistance heating elements may incorporate at least one other heating technology, such as steam generation or microwave generation, and which further may be provided with a pyrolytic cleaning capacity.
[0042] In FIG. 5 there is shown an exploded view of a further embodiment of a sensor assembly 10 in accordance with the present invention.
[0043] The sensor assembly 10 shown in FIG. 5 comprises a generally box shaped housing 12 which at one end comprises an integrally formed air inlet 16. Housing 12 which is open at its upper side comprises a bottom wall 28 in which there are provided a plurality of outlet openings 43 which are located to form a circle around a central opening 44. Within housing 12 there is located a sensor element 14, which in the embodiment depicted in Fig, 5 is designed as an optical sensor having a camera element 46 which in the assembled state is located above central opening 44. Above sensor element 14 there is shown a heat sink 20 which in the assembled state contacts sensor element 14 so as to withdraw heat from the sensor element. Similarly as the heat sink 20 shown in FIG. 4, also in the embodiment shown in FIG. 5 the heat sink 20 comprises a plurality of lamellas 42 so as to increase the surface area of heat sink 20 about a channel 48 through which air is passed during use of the sensor assembly. The opening at the upper side of housing 12 is closed by a lid 50, which further also could be formed as an integral part with the heat sink 20.
[0044] While so far the sensor assembly 10 shown in FIG. 5 is similar to the one shown in FIGS. 2 and 4, in the FIG. 5 embodiment there is provided a housing support 52 for mounting the sensor assembly to a wall of the oven cavity, either at the exterior side or at the interior side thereof. The housing support 52 is made of a temperature resistant material which preferably has a lower thermal conductivity than the housing 12 so as to provide for thermal protection thereof. Housing support 52 comprises at its upper side an annular wall 54 within which there is provided a receptacle (not shown in FIG. 5) for a transparent element 32, and which forms together with an annular element 56 an annular channel for air leaving outlet openings 28. Housing support 52 further comprises supports 58 and 60 for supporting the bottom wall 28 of housing 12. In order to provide for additional thermal insulation of housing 12, an insulation layer 62 is provided at the bottom wall 18 of housing 12.
[0045] In FIG. 6 there is shown a sensor assembly similar as the one shown in FIG. 5, wherein the assembly comprises a housing 12 that is mounted on a housing support 52. However, in the embodiment shown in FIG. 6, the assembly is designed for use with a humidity sensor 64. Furthermore, in contrast to the embodiment shown in FIG. 5, where the air used for cooling the sensor is expelled into the oven cavity, in the embodiment shown in FIG. 6 there is provided an air outlet 18 as is shown also in FIG. 1.
[0046] Correspondingly the bottom wall 18 of housing 12 has no air opening 28 as shown in FIG. 5, but only is provided with an opening 44 that is in alignment with the humidity sensor 64 as shown in FIG. 6. In order to protect humidity sensor 64 from contact with water droplets or other particles contained in the oven fumes, there is provided an annular element 66 which carries a membrane 68 that is permeable to water vapor. Element 70 shown in FIG. 6 is a connection ring for mounting humidity sensor 64 within housing 12.
REFERENCE SIGNS
[0047] 10 sensor assembly
[0048] 12 housing
[0049] 14 sensor element
[0050] 16 air inlet
[0051] 18 air outlet
[0052] 20 heat sink
[0053] 22 oven cavity
[0054] 24 upper wall of oven muffle
[0055] 26 annular portion
[0056] 28 bottom wall of 12
[0057] 30 opening in 24
[0058] 32 transparent element
[0059] 34 wall of 12
[0060] 16 air outlet
[0061] 37 openings
[0062] 38 outlet openings
[0063] 39 metallic wall
[0064] 40 aperture
[0065] 42 fins
[0066] 43 outlet openings
[0067] 44 central opening
[0068] 46 camera element
[0069] 48 channel
[0070] 50 lid
[0071] 52 housing support
[0072] 54 annular wall
[0073] 56 annular element
[0074] 58 support
[0075] 60 support
[0076] 62 insulation layer
[0077] 64 humidity sensor
[0078] 66 annular element
[0079] 68 membrane
[0080] 70 connection ring
