EP2130016A2

EP2130016A2 - Temperature probe for an oven, oven and method for operating an oven

Info

Publication number: EP2130016A2
Application number: EP08716396A
Authority: EP
Inventors: Martin Baier
Original assignee: EGO Elektro Geratebau GmbH
Current assignee: EGO Elektro Geratebau GmbH
Priority date: 2007-03-30
Filing date: 2008-03-10
Publication date: 2009-12-09
Also published as: DE102007018245A1; US8188409B2; US20100012645A1; WO2008119440A3; WO2008119440A2

Abstract

The invention relates to a temperature probe (11) for an oven (35), comprising a longitudinal housing (12) in the form of a spit. A temperature sensor (24) and an electronic unit (25) are arranged in a tip (13) and are connected at the other end (22) to emitting means (21). The temperature probe (11) comprises a thermogenerator (31) for producing energy (19). The thermogenerator (31) uses a temperature difference between a higher temperature inside the oven (35) and a lower core temperature in a roast (15), in which the temperature probe (11) is inserted, for producing energy (19) for operating the emitting means (21).

Description

description

Temperature probe for a stove. Oven and method of operating a

furnace

Field of application and state of the art

The invention relates to a temperature probe for a furnace, which can be inserted into food, and a furnace with such a temperature probe and a method for controlling such a furnace.

From EP 687 666 A an oven with a temperature probe is known as a so-called spit. During the cooking process or the operation of the oven with a food such as a roast, the elongated, spit-like temperature probe is inserted into the food and can detect the temperature of the food with a temperature sensor in the top. Via a cable, the temperature probe is connected to the furnace and transmits with a transmitter the temperature information of the temperature sensor to a furnace control. Thus, the temperature in the interior or core of the food can be detected for an automatic program or a kind of automatic procedure. The disadvantage here, however, is that such a temperature probe is wired. This reference also describes a temperature probe with a transmitter, for example a radio transmitter. To power a battery is provided. The use of energy storage devices such as batteries or the like. for a transmitting device is in the oven, however, difficult because they would be destroyed at the temperatures occurring above 200 ⁰ C.

From EP 1 624 724 A, another oven with a temperature probe is known as a spit. Among other things, a thermogenerator is mentioned for supplying energy to the temperature probe. However, that is this possibility is shown in a way that makes the actual operation of a thermal generator technically absolutely impossible, and also from the entire disclosure can not be found how a power supply could be realized with a thermal generator.

Task and solution

The invention has for its object to provide a temperature probe mentioned above, a furnace mentioned above and an aforementioned method with which disadvantages of the prior art can be avoided and in particular a lighter and more manageable temperature probe can be created.

This object is achieved by a temperature probe with the features of claim 1, a furnace having the features of claim 10 and a method having the features of claim 15. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. Although some features of the invention will be explained only once. However, they should be independently applicable to all aspects of the invention of temperature probe, oven or process. The wording of the claims is incorporated herein by express reference. Furthermore, the wording of the priority applications DE 102007016452.3 of 30 March 2007 and DE 102007018245.9 of 12 April 2007 of the same Applicant are incorporated by express reference into the content of the present description.

According to the invention, the temperature probe for generating energy for the transmitting means, wherein the power generation is designed such that it draws or generates the energy from their environment in the oven during the operation of the furnace. So can sensitive energy storage as batteries or accumulators are dispensed with and yet electrical energy to operate the transmission means are generated. At the same time, there are certain energy sources already present in the furnace, as will be explained in more detail below. So it's mainly about the new way of generating energy. Thus, with the invention, a wireless temperature probe can be created, which is versatile and whose temperature information is transmitted wirelessly to a furnace control. Elaborate or expensive and possibly prone technical solutions such as transponders, transmission devices with surface wave technology or the like. can be avoided.

According to a basic embodiment of the invention, the temperature probe on an elongated housing and is adapted to be inserted into a food. This is suitable, for example, for a food such as a roast. Thus, the temperature can be detected in Gargutinneren, which is an important parameter for operation, especially an automatic operation. The housing may have a tip that may be hollow to accommodate components therein, especially the temperature sensor.

According to an alternative basic embodiment of the invention, the housing or the temperature probe can be flat, in particular disk-like. Thus, the temperature probe can detect the temperature on a food such as a pizza, which is not suitable for insertion of an aforementioned elongated temperature probe, and attached thereto, for example by laying directly on it. Alternatively, such a flat temperature probe or the like on a storage form or a baking sheet. be mounted for the food, especially on the underside. Even so, a thermally conductive connection or a thermal contact with the food to be cooked is possible to detect its temperature. At the same time, as with the application of a flat temperature probe to the food to be cooked, one possibility is the temperature probe in the oven interior. - A -

that it is accessible to energy production or that it can be supplied with energy. This will be explained in more detail below.

To generate energy from the environment in the oven, there are several possibilities. According to a first basic possibility, a power generation can be designed to obtain the energy from a heat or temperature difference between a warmer area and a colder area. As a warmer area, the interior of the oven can serve. As a colder area can serve the surface or the interior of the food, in which the temperature probe is inserted or with which it is in heat-conducting connection. Energy can be drawn from this temperature difference between the warmer region and the colder region, for which purpose a heat generator based on the Seebeck effect can advantageously be used. The energy generated thereby may not be very large. However, if the transmitters do not require a lot of energy, it is enough.

For such a thermogenerator, a first slice of good heat-conducting material may be provided on the temperature probe, in particular on a region remote from the food or the temperature sensor, for example copper. This first disc is associated with a second disc, on the side to the food or temperature sensor out. The two disks are provided at a small distance and advantageously parallel to each other at the temperature probe.

The two discs are interconnected, but advantageously thermally insulated from each other. A mechanical connection can also be made via the thermogenerator. A possibly provided between the two discs seal can take over the task of thermal insulation. The second disc is in heat-conducting connection with the region of the temperature probe, which has the temperature sensor or is inserted into the food or contacted this. By this thermally conductive connection, the second disc is cooled due to the lower temperature Garguts and, as a result, the contacting portion of the temperature probe. Such a heat-conducting connection can, for example, generally have a type of heat-conducting rod or a thermal bridge of the highest possible thermal conductivity, such as, for example, copper or metal. The thermally conductive connection can preferably form a substantial part of the cross section of the temperature probe, for example also be the housing or a part of the housing, in particular a housing jacket.

The thermal generator is arranged between the first disc and the second disc. Advantageously, a gap between the two disks around the thermogenerator is sealed to the outside against dirt. Inside the housing of the temperature probe, the thermogenerator can then be connected as an energy source with the aforementioned electronics or the transmitting means. Since thermal generators are in some cases relatively small, for example, have a size of about 10 mm × 10 mm, a plurality of thermal generators can also be arranged next to one another between the panes.

It is regarded as advantageous if the first disk or the thermal generator has a certain distance from the free end of the temperature probe, for example a few centimeters. As a result, a transmitting device or an antenna of the transmitting means can transmit the temperature information unhindered and also with a lower necessary transmitting power. Alternatively, a disk or housing part may be used as the antenna.

According to another basic possibility for energy production, a photovoltaic effect can be used to generate electricity. energy from light in the furnace. Ambient light may be added to this light in the oven through a translucent oven door. For the photovoltaic effect can advantageously be used a solar cell. Such a solar cell is, as described previously for the thermogenerator, advantageously arranged away from the plugged into the food end. It is considered advantageous if the solar cell is tuned by its electrical properties to the light prevailing in the oven or its wavelength. Furthermore, the orientation of the solar cell can be changed or aligned in such a way that it is as perpendicular as possible to a light source in the furnace for the best possible incidence of light or the highest possible energy yield. For this purpose, alternatively, an area of the solar cell can be inclined to the longitudinal axis of the temperature probe which is advantageously straight. Thus, by rotating the temperature probe about its longitudinal axis, which is easily possible when inserted into the food to be cooked, an alignment can be made without mechanically movable joints or the like. to need.

A solar cell may alternatively or additionally be designed to generate electrical energy from radiation in the non-visible wavelength range, in particular from heat radiation in an oven from a radiant heating of the furnace. For this example, GaAs solar cells are suitable. It is also possible to use stack cells for a plurality of wavelength ranges.

As mentioned, the temperature probe can have electronics for evaluating the temperature or the temperature sensor. Since such electronics may be sensitive to heat, they should be located in an end region to be inserted into the food or close to this end region or the temperature sensor arranged therein. Furthermore, it is possible to design the electronics as high-temperature electronics. The SOI technology is ideal for this. Usable thermogenerators are produced, for example, by Mikropelt GmbH, Freiburg. Their performance can be at a temperature difference of 10 ° C to 20 ⁰ C at slightly more than one mW, which may be sufficient for appropriately trained transmitting means. Important in a selection of a corresponding photovoltaic or solar cell is also the temperature resistance to, for example, 250 ⁰ C. Here, solar cells are used, as used in space.

Advantageously, it can be provided for a measurement of the temperature as possible in the middle or in the core of the food that the temperature sensor is located far to the front of the temperature probe end. For this purpose, it may advantageously have a kind of tip. In a further embodiment of the invention, it is also possible to provide a plurality of temperature sensors along the housing. These are then all evaluated by the electronics so as to obtain a kind of temperature profile of the food from the outside to the core or even through it or to measure a kind of averaged temperature. In any case, the core temperature can be determined relatively accurately as well as the lowest temperature in the food, regardless of the depth of insertion of the temperature probe. The evaluation of several temperature sensors by the electronics is not a big problem.

As previously mentioned, electronics may be located either as close as possible to a tip of a housing, and thus probably far inside the food. So it can be as far as possible within the food and thus in a relation to the other oven cooler area. Alternatively, an electronics can be arranged on the cooler disc, since this also has a temperature well below the temperature of the furnace interior. This is particularly the case with a disk-type temperature probe. An inventive furnace, which can be operated with an aforementioned temperature probe or forms a functional unit with this, has receiving means to receive the temperature information sent by the transmitting means. Thus, the oven or a furnace control can receive and use the temperature information from the temperature sensor in the temperature probe or in the food to be cooked, for example, further processing, as is known from the prior art. The operating frequency for the transmitting means and receiving means is favorably chosen for the transmission of such temperature information. The range does not need to be particularly large, since in particular the receiving means in the interior of the oven or a furnace muffle or the like. can be arranged. The operating frequency can be chosen in a substantially arbitrary range. Since the transmission power of the transmitting means is usually very low, hardly occur radio waves from the oven to the outside.

In an embodiment of the invention, at least one storage area for the temperature probe can be provided on the oven, advantageously in its interior. Such a storage area is at least partially shielded from the interior of the oven and has an opening to insert the temperature probe therein. By shielding against the interior of the furnace is achieved that in the storage area a cooler temperature than in the other furnace interior prevails and here the temperature probe, if it is not required for the operation of the furnace, is stored as if it were introduced into a food, which is also cooler than the other interior of the oven. For example, such a storage area may be formed as a kind of pocket on an inner wall of the interior of the furnace. Alternatively, an elongate storage area may extend away from the oven interior into the housing of the oven, where it is also cooler than in the oven or oven muffle. Advantageously, the storage area is thermally insulated from the oven muffle. He should also be in operation of the furnace be cooler than 100 ⁰ C ₁ at high temperatures so that sensitive parts or electronics of the temperature probe are protected and not destroyed. Even short-term overshoots in the temperature up to 120 ⁰ C may occur.

In a further embodiment of the invention, the oven may have a detection device on the storage area. As a result, it can be detected in the oven operation whether the temperature probe is located therein or inserted therein, at least one front area of the temperature probe with electronics or temperature sensor. This detection means may be connected to an oven controller and in the oven operating procedure, prevent the oven from being heated to higher temperatures when the temperature probe is not in the storage area.

Furthermore, a detection device can be designed so that it detects when no temperature signals are sent from the temperature sensor or come from the temperature probe. There can be three cases here. As a first possible case, the temperature probe is in the storage area, which can be detected by the detection means, and then any operation of the oven is possible. As a second possible case, the temperature probe can be plugged into a food, and due to the temperature difference send the sending means temperature information. A third possible case is that neither the first nor the second case exist. This is usually a so-called error case, for example, when the temperature probe is located next to a food in the oven interior. Due to the lack of temperature difference, it can not send any temperature information as it can not generate electrical energy. In this respect, an operator should be informed that the temperature probe is not functional. Furthermore, there is the problem here that the tempera probe is fully exposed to the temperature of the oven interior and can overheat, which can result in damage or destruction. Here too, the temperature probe is to be protected by, for example, issuing a warning signal and advantageously also the furnace can not reach temperatures which are too high, for example not more than 100 ^° C.

The detection device can either have a kind of mechanical switch. This can be actuated by inserting the temperature probe in the storage area or when inserting or removing the temperature probe change its switching state. Alternatively, the detection device may comprise a proximity sensor, which operates in particular without contact. Such a proximity sensor may operate magnetically, for example with a Hall sensor for detecting a magnet provided specifically for the temperature probe or inductively or capacitively, such proximity sensors being known to the person skilled in the art.

In order to save energy, the transmission of the temperature information by means of the transmission means can be done either continuously or at certain time intervals, in particular periodically. Furthermore, it is possible that a short-term energy storage takes place in the temperature probe, for example via a temperature-resistant capacitor. Thus, for a periodic operation of the transmission means for a longer time energy can be collected and then consumed in a shorter time to send, for example, every one to 30 seconds is sent.

In a further embodiment of the invention, a furnace may be designed so that it can be operated in multiple temperature probes. To distinguish the respective temperature information, depending on the different food or previous dwell time of this food In the oven inside so different temperatures can measure, they can have an individual coding. This coding can always be sent along with the temperature information about the transmitting means and be recognized and distinguished by the receiving means. Thus, for example, it is also possible to input at a furnace control which food to be cooked or which has been finished by a respective temperature probe equipped with an identification and thus can be removed. It can also be provided that a furnace can be operated both with a spit-like temperature probe and a flat, disk-like temperature probe. Thus, depending on the food of the optimal temperature sensor can be used, so for example a spit-like temperature sensor for frying and a disk-like temperature probe for a pizza or the like. By different frequency coding can recognize a furnace control, which temperature probe is currently in use and may be a correction of the sent Make temperature values. Another way to encode may be to transmit at different frequencies.

An encryption of the temperature information can be done instead of a signal containing the exact temperature information, also by varying transmission intervals. AII as five to ten seconds, for example, be sent a short signal, which then means a temperature of 50 ⁰ C, a temperature of 70 ⁰ C can be sent by a brief radio signal every seven seconds, etc ..

These and other features will become apparent from the claims and from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in one embodiment of the invention and in other areas be realized and advantageous and protectable - ge represent versions for which protection is claimed here. The subdivision of the application into individual sections and subheadings does not limit the statements made thereunder in their generality.

Brief description of the drawings

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

1 shows a section through a temperature probe according to the invention with thermogenerator, which is plugged into a food,

2 is a schematic sectional view of a furnace according to the invention with a storage area for the temperature probe,

3 shows a modification of the temperature probe from FIG. 1 with an upper disk of the power generation, which is bent over into the plane of the lower disk, FIG.

Fig. 4 similar to a modification of the furnace according to the invention

Fig. 2 with disc-like temperature probes and

Fig. 5 is an enlarged view of a disk-shaped temperature probe similar to FIG. 4 in section.

Detailed description of the embodiments

In Fig. 1, a temperature probe 11 according to the invention is shown, which is constructed in the manner of a so-called Bratenspießes. The temperature probe 11 has an elongated, tubular housing 12, which opens forward in a tip 13. This is plugged into a roast 15 as a food. In this case, the housing has a housing jacket 17 made of a material suitable for operating conditions of a roasting spit, for example made of copper for improved heat conduction. It may also be coated or provided with a thin stainless steel casing for food hygiene. To the housing 12, a disk-shaped power generation 19 connects. This in turn carries an end cap 22, in the transmission means 21 in the manner of an antenna or the like. are arranged to protect them.

In the tip 13 of the temperature probe 11, a temperature sensor 24 is arranged, which is connected to an electronics 25. The electronics 25 is designed to evaluate the temperature sensor 24 and to transmit temperature information via the connection to the transmitting means 21 or to send to corresponding receiving means. Although the electronics 25 is characterized by the fact that it also sits far ahead of the top 13, protected from excessively high temperatures when it is plugged into the roast 15. However, it is advantageously provided to carry out in the aforementioned SOI technology so that it can withstand high temperatures. In the course between peak 13 and power generation, other temperature sensors could be provided, as previously mentioned.

The arranged on the housing 12 power generation 19 is a total disk-like design. It has a first disk 27 and a plane-parallel second disk 28. The two discs 27 and 28 have a small distance from each other. Both discs are the same shape, in particular as circular discs, and may consist of the same material, advantageously good heat conducting material such as copper, which may be coated or provided with a Edelstahlplattie- tion. The second disc 28 is connected by means of a weld 29 with the rear end of the housing 12, wherein such a weld 29 can not only serve the mechanical attachment, but also produce a very good heat conducting connection between the housing 12 and the second disc 28. In this respect, it is also possible, instead of the weld 29, a kind of wide flange or the like. to provide for the best possible heat-conducting Connection between the two parts. To the rear, the first disc 27 is connected to the end cap 22.

Between the discs 27 and 28, a thermogenerator 31 and a plurality of thermal generators is provided. To the outside of this or between the discs 27 and 28 formed gap is sealed by a suitable for the oven operation seal 32. The thermogenerator 31 is connected at its top as good as possible or thermally conductive with the first disc 27, which forms the hot side. On its underside it is connected to the second disc 28, which forms the cooling side.

The function of the power generation 19 is as follows: During operation of the oven with inserted fry 15, in which the temperature probe 11 is inserted, the temperature sensor 24 detects the temperature inside the roast 15 or the so-called core temperature. While the environment in the furnace increases according to operation, for example, 200 ⁰ C, and thus also heats the protruding part of the temperature probe 11 and especially the first disc 27 as a warm side, the housing 12 is located for the most part in the cooler roast 15th Die shown in solid broad arrows represent the hot side. the core temperature of the roast 15 usually increases even after prolonged roasting time not more than 90 ⁰ C, so that the housing 12 has at least the front of the tip 13 at the same temperature. Due to the heat-conductive design of the housing shell 17 and the best possible heat-conductive connection 29 to the second disc 28 as a cooling side, this is cooled to a certain extent, as shown by the dashed wide arrows, which should represent the cooling side.

Thus, the second disk 28 is slightly cooler than the first disk 27. As a result, a temperature difference is given by the warm side of the thermal generator 21 to the cooling side, which according to the vorge Seebeck effect can be used to generate electrical energy, which is conducted via conductive connections to the electronics 25. Thus, the electronics 25 can be operated and, above all, send out the temperature information of the temperature sensor 24 via the transmission means 21.

Of course, numerous variations of power generation 19 with a thermal generator are possible. A thermogenerator could be at least with its cooling side even closer to the roast 15 in order to obtain an even greater temperature difference. Variations thereof are easily conceivable for the skilled person.

As an alternative to energy generation 19 with a thermogenerator 31, solar cells could be provided on a similarly disk-shaped or planar energy generation, as mentioned above. In particular, they are provided instead of the first disc 27, that is to be able to be well irradiated at the side facing away from the top 13 side up by a furnace lighting. As explained above, in solar cells, the disk-shaped power generation 19, which is then a support for the solar cells, an angle deviating from 90 ° to the longitudinal axis of the housing 12 to 12 by rotating the temperature probe around its longitudinal axis as good as possible alignment to a furnace lighting to have. However, this is easy to realize for the skilled person.

In Fig. 2 is a sectional view through an O fen fen 35 is shown, which has a furnace muffle 36 and is formed as a baking oven. In the oven muffle 36 is an upper heating 38a and a lower heating 38b and a support plate 39, which carries a roast mold 40 with the roast 15. Furthermore, a furnace lighting 41 is provided, as is usual with a corresponding temperature-resistant lamp. Finally, a furnace control 42 is provided, which, inter alia, connected to the heaters 38a and 38b is. Furthermore, the oven control 42 is connected to receiving means 44, which may be arranged, for example, on the inner wall of the oven muffle 36.

On the right in the oven muffle 36, a storage area 46 for a temperature probe 11 is shown with a chamber 47, which extends a bit into the oven muffle 36 and, above all, runs out of it. It is accessible from the oven muffle 36 through a chamber opening 48 for the illustrated insertion of the temperature probe 11a. Furthermore, the chamber 47 is formed both by their structural design, which is not shown here, as well as by their course substantially outside the furnace muffle 36 so that a temperature therein is considerably lower than in the furnace muffle itself, advantageously 120 ⁰ C or even only 100 ⁰ C does not exceed. This will be explained in more detail below. Furthermore, a switch 50 with a switching arm 51 is provided on the chamber 47. Switch 50 and switch arm 51 are designed so that when empty chamber 47 or without temperature probe 11 of the switching arm 51, for example, depends down. By inserting the temperature probe 11 a, it is deflected to the right and actuates the switch 50. The oven control 42 is electrically connected to the switch 50 and thus registers its switching state and thus also when the switch is actuated by deflection of the switching arm 51 to the left or to the right or a temperature probe 11 is inserted into the chamber 47 or not.

Thus, Fig. 2 shows with the temperature probe 11a the first case mentioned above, namely that the temperature probe 11a is inserted in the chamber 47 as a storage area 46, because it is not needed. At the same time, it is achieved that the temperature probe 11a or an electronics 25 contained therein is protected from overtemperature by the lower temperature in the chamber 47 and thus is not damaged. The oven controller 42 recognizes this first case about the operating state of the switch 50. The aforementioned second case with the temperature probe 11b inserted in the roast 15 results in electrical energy being generated by the thermo generator 31 and the temperature probe 11b generating temperature information about the transmitting means 21 to the receiving means 44 on the basis of the temperature difference described for FIG sends. The furnace controller 42 receives this temperature information from the receiving means 44 and evaluates it, for example, for an automatic program for cooking the roast 15. By inserting the temperature probe 11b in the roast 15 here the electronics 25 remains below a critical temperature.

The aforementioned third case is illustrated by the temperature probe 11c. Here, the temperature probe 11c has been forgotten, so to speak, or lies on the baking sheet 39. As a result, it is fully exposed to the temperature in the oven muffle 36 and they or the electronics 25 could be damaged during operation by overheating. This third case, can be recognized by the fact that even after a few minutes, a temperature difference at the temperature probe is missing and thus the thermogenerator can not generate energy to send temperature information. Thus, if no temperature information is received at the receiving means 44 and also the switch 50 has not registered the insertion of the temperature probe 11 in the storage area 46, this is recognized by the oven controller 42 as this third case. The third case is defined, so to speak, when neither the first nor the second case exists. The oven controller 42 prevents the oven from being heated to a temperature detrimental to the electronics 25. At the same time, a kind of warning signal can be displayed to an operator.

Since the third case with the temperature probe 11c can not be realized in the same way in a photovoltaic power generation, since this does not depend on a temperature difference, here an alternative is necessary. Advantageously, a temperature at the temperature sensor is already measured by the energy production at the photovoltaic power generation. Exceeds its temperature a predetermined value of, for example, 70 ⁰ C or 80 ⁰ C, the furnace control switches off as in normal operation. At the same time, a corresponding warning signal can be generated by the fact that the temperature rises even further and this is in sign that the temperature probe can not stick in a roast.

Such a temperature sensor at the back of the temperature probe would also have the advantage that it can generally be used as a temperature sensor for the interior of the oven muffle 36 in a relatively central location where normally no temperature sensor is present. In this respect, its temperature information in general for the operation of the oven 35, in particular with an automatic program, could be helpful and useful.

In Fig. 3, a part of a modification of a temperature probe 111 is shown similar to that of Fig. 1. However, here, as a difference, a first disk 127 is closed as a warm side on its upper side, thus has no passage for an antenna at a rear end. At the outer edge of the first disc 127 is bent or flared inwardly by 180 ° and extends a piece inwards. By means of a seal 132, which should thermally isolate as well as possible, she holds a second disc 128 and forms with her, similar to that shown in Fig. 1, a housing for power generation 119. The second disc 128 forms the cold side.

Between the discs 127 and 128, thermal generators 131 are provided, distributed around a lower opening in the second disc 128, which, similar to FIG. 1, is connected to a tubular housing shell 117 via the weld 129. Furthermore For example, the electronics 125 are attached to the second disk 128, which is cooler than the first one and, as a rule, sufficiently cool to not damage the electronics 125.

The area of the first disk 127 is greatly increased in relation to FIG. 1, and almost doubled. This allows a better and faster heating of the first disk 127 to a furnace temperature. The second disc 128 is reduced in size, which in turn reduces the influence of the furnace temperature on it as a cold side and thus this remains even cooler. Thus, by the formation of the two disks 127 and 128, an achievable temperature difference for the thermal generators 131 is greater and thus the energy yield better.

In the second basic embodiment of the invention according to FIG. 4, a disk-like temperature probe 211 is provided in an oven 235. Above a lower heating 238b, a baking tray 240 carries a pizza 215 as food to be cooked. Both by the lower heater 238b and by an upper heater, not shown, of the oven 235, the interior 236 is heated as usual in the preparation of pizza.

Since a spit-like temperature probe similar to FIG. 1 could not be inserted in the case of a food item such as, for example, pizza 215, the above-described disc-type temperature probes 211a or 211b are provided here. The temperature probe 211a is placed with its bottom, which corresponds to a cold side, directly on the pizza. The temperature probe 211b, which is fastened to the baking tray 240 from below, is arranged with its cold side upwards, that is to say towards the pizza 215. An arrangement of a temperature probe 211b on the underside of the baking sheet 240 can be effected either by a mechanical closure in any desired form or by a magnetic holder. Alternatively, a temperature probe can also be firmly integrated or installed in a baking tray. From Fig. 5, the exact structure of such a disk-like temperature probe 211 can be seen. A first disc 227 forms the warm side. It is, similar as in Fig. 1, connected via seals 232 with a second disc 228, which forms a cold side. Disposed between the disks are two or more thermal generators 231 which are connected to electronics 225 for powering. Furthermore, the electronics 225 also includes a transmitting device and is connected to the first disc 227 as an antenna.

In Fig. 5, similar to in Fig. 1, shown by solid and dashed arrows heat to the hot side of the first disc 227 and a cooling of the cold side of the second disc 228 by placing on the pizza 215. Although it can be assumed here that a temperature difference may be lower than with a einzusteckenden, pike-like temperature probe. However, cooling is still provided by the two-dimensional placement of the temperature probe 211 on the pizza 215.

As a result of the fact that the electronics 225 are arranged on the second disk 228 as in FIG. 3 and have some distance from the first disk 227, they remain cool. Under certain circumstances, it may be necessary to use a named temperature-resistant electronics. By attaching the temperature sensor 224 to the second disk 228, which is thermally coupled to the pizza directly or via the sheet 240, it can detect its temperature relatively accurately. Under certain circumstances, correction factors can also be used here in the electronics 225 or a furnace control.

It can also be seen from FIG. 4 that, at least when a temperature probe 211a is arranged on top of the pizza 215, energy generation could also take place via a prescribed photovoltaic, in which case the first slice 227 in the temperature probe 211 according to FIG has a corresponding solar cell assignment. Furthermore, sending the temperature information up from the baking tray 240 is not a problem. For a temperature probe 211 b under the baking tray 240 is either a special baking sheet to provide, which does not hinder the transmission of temperature information. Alternatively, another receiver could be provided below the baking tray 240 in the oven 235. In the case of the temperature probe 211b or its arrangement under the baking tray 240, the use of photovoltaic power generation is less advantageous.

Finally, it is possible that various temperature probes can be operated in an oven, ie both spit-like temperature probes 11 according to FIG. 2 for insertion into food to be cooked and flat or disk-like temperature probes 211 according to FIG. By coding their radio signals or temperature information, they can be distinguished and the oven can adjust itself automatically with its oven control.

Claims

claims

A temperature probe (11, 111, 211) for an oven (35, 235) for detecting the temperature of the item to be cooked (15, 215), such as a roast or a pizza, the temperature probe (11, 111, 211) housing ( 12, 112) with a temperature sensor (24, 224) for detecting the temperature of the food (15, 215) by contact of the temperature probe with the food to be cooked, wherein the temperature probe (11, 111, 211) transmitting means (21, 227) for Transmission of temperature information on the temperature detected by the temperature sensor (24, 224) to receiving means (44) in the furnace (35, 235), characterized by energy generation (19, 119, 219) for the transmitting means (21, 227) from energy from the environment in the oven (35, 235) during operation of the oven.

2. Temperature probe according to claim 1, characterized in that the housing (12, 112) is elongated for insertion of the temperature probe with the temperature sensor (24) in the food (15) for detecting the temperature of the food (15) in Gargutinneren, preferably the temperature sensor (24) is arranged at the end or near a tip (13) of the elongated temperature probe (11, 111) to be inserted into the food item (15).

3. Temperature probe according to claim 1, characterized in that the housing (227, 228) is flat for attaching the temperature probe with the temperature sensor (224) on the food (215) such as a pizza, preferably by placing it on the food with direct contact or attaching the temperature probe to a baking sheet (240) or the like, on which the food is to be cooked.

4. Temperature probe according to claim 3, characterized in that the temperature sensor (224) is arranged close to an area to be cooked on the food probe (211), preferably directly to a housing wall or disc (228).

5. Temperature probe according to one of the preceding claims, characterized in that the energy generation (19, 119, 219) is adapted to energy from heat or a temperature difference between the interior of the furnace (35, 235) as a warmer area and with a the food to be cooked (15, 215) in thermally conductive connection area (13, 228) of the temperature probe (11, 111, 211) as a colder area, wherein in particular the energy generation comprises a thermal generator (31, 131, 231).

6. Temperature probe according to claim 5, characterized in that the temperature probe (11, 111, 211), in particular close to one of the temperature sensor (24, 224) remote end (22) at an elongated temperature probe, a first disc (27, 127 , 227) of highly thermally conductive material, preferably made of copper, wherein the first disc (27, 127, 227) is associated with a second disc (28, 128, 228) to the temperature sensor (24, 224) out at a short distance and optionally parallel to the temperature probe (11, 111, 211) is arranged, wherein the second disc (28, 128, 228) in heat-conducting connection with a portion (13) of the temperature probe with the temperature sensor (24, 224) to the food (15, 215) is due to the lower temperature of the region of the temperature probe (11, 111, 211) in or on the food for cooling the second disc.

7. Temperature probe according to claim 6, characterized in that the heat-conducting compound has a Wärmeleitstab of good heat conducting material, preferably of copper, in particular forming a substantial part of the cross section of the temperature probe (11, 111) and preferably a part (17, 117 ) of the housing (12, 112) forms.

8. Temperature probe according to claim 6 or 7, characterized in that the thermal generator (31, 131, 231) between the first disc (27, 127, 227) and the second disc (28, 128, 228) is arranged.

9. Temperature probe according to one of the preceding claims, characterized in that the temperature probe (11, 111, 211) has an electronics (25, 125, 225) for evaluating the temperature to be contacted in a to the food (15, 215) End region (13, 228) or close to the temperature sensor (24, 224) is arranged, wherein preferably the electronics (25, 225) is designed as high-temperature electronics, in particular in the SOI technology.

10. oven with at least one temperature probe according to one of the preceding claims, characterized in that the furnace (35, 235) receiving means (44) to the temperature information of the transmitting means (21, 227) of the temperature probe (11, 111, 211) and of the temperature sensor (24, 224) and to use in a furnace control (42), or possibly weiterzu- process.

11. Oven according to claim 10, characterized in that in the interior of the furnace (35) at least one storage area (46) for the temperature probe (11 a) is provided, wherein a Aufbewah- at least partially shielded from the interior (36) of the oven (35) with an opening (48) for insertion of the temperature probe (11a) therein, in particular also for holding the temperature probe, wherein in particular the storage area (46) is formed is that its internal space (47) shielded from the interior (36) of the furnace (35) is significantly cooler than the interior (36) of the furnace when the furnace (35) is in operation.

12. Oven according to claim 11, characterized in that on the storage area (46) a detection device (50, 51) is provided for detecting whether the temperature probe (11a) or at least a part of the temperature probe (11a) is located therein, in particular a An area (13) having electronics (25), wherein in particular the detection means (50, 51) is connected to a furnace controller (42) for preventing operation of the furnace (35) in the event that the temperature probe (11) is not in the storage area (46) is or sends no temperature signals from the temperature sensor (24).

13. Oven according to claim 12, characterized in that the detection device comprises a mechanical switch (50) which is actuated in the storage area located in the temperature probe (11 a) or has a different switching state than when removed temperature probe (11).

14. Oven according to claim 12, characterized in that the detection device comprises a proximity sensor which detects the presence of the temperature probe (11a) in the storage area, in particular contactless, wherein preferably the detection device operates magnetically or capacitively.

15. A method for operating a temperature probe (11, 111, 211) according to one of claims 1 to 9 in a furnace (35, 235) according to one of claims 10 to 14, characterized in that one of three cases is determined, namely:

as the first possible case, whether the temperature probe (11a) is in the storage area (46)

- As a second possible case, whether the temperature probe (11b) in heat-conducting connection with a food (15) and due to the temperature difference temperature information via the transmitting means (21, 227) sends

- As the third possible case, whether the first or the second case are present, the furnace (35, 235) is operated in the first case and in the second case as desired with any selectable operating temperature and in the third case to a maximum of 120 ⁰ C.