DE102018207615B4 - Method for operating a household microwave device and household microwave device for carrying out the method - Google Patents

Abstract

Method for operating a domestic microwave appliance (1), having a microwave generator (3, 4) for generating microwaves, a treatment chamber (2) which can be acted upon by the microwaves and at least one sensor (9, 11, 13) for detecting at least one item of sensor information (T1, T2, Uactual), in which methoda) an associated microwave is selected from at least one user setting (Ps, ts), which comprises at least one microwave setpoint power (Ps), for a microwave heating process n total energy (E) is determined,b) based on at least one piece of sensor information (T1, T2, Uactual) and the set microwave target power (Ps), a time profile of a future available microwave power (Pv) that can be called up for the microwave heating process is determined, c) based on the time profile of the microwave power available (Pv), a time profile of the microwave power (Pm) actually to be fed in is determined, which corresponds to the associated microwave power insertion power (Pv) at no time and has the same total microwave energy (E) as the total microwave energy (E) determined from the user settings (Ps, ts), andd) a remaining time (tr) of the microwave heating process is determined from the curve of the microwave power (Pm) actually to be fed in.

Description

The invention relates to a method for operating a household microwave appliance, having a microwave generator for generating microwaves, a treatment chamber that can be subjected to the microwaves, and at least one sensor for detecting at least one item of sensor information. The invention also relates to a domestic microwave oven that is set up to carry out the method. The invention can be applied particularly advantageously to stand-alone microwave devices and cooking devices with an additional microwave function.

Previously common practice in household microwave devices are heating processes in which a user selects or sets one of several desired microwave powers. While the microwave power actually radiated into the treatment room (“actual microwave power”) at the beginning of a microwave heating process corresponds to the target microwave power, at least for a cold household microwave appliance, the actual microwave power is subsequently often due to increasing losses in the power source due to self-heating, through the intervention of protection limitations, in particular thermal protection limitations (e.g. in the case of high-voltage transformers), or by deliberately reducing the power in microwave devices with inverter technology (e.g. in high-voltage switched-mode power supplies for supplying the magnetron). If the domestic microwave oven is still warm at the beginning of the microwave heating process, e.g. because it was used shortly before, the microwave set power may not be available at the beginning of the heating process. If the household microwave appliance has a display device, this always shows the desired microwave power selected by the user, even if the actual microwave power generated falls below the set microwave desired power.

The hitherto customary practice has the disadvantage that it is comparatively difficult for a user to set the correct operating time for the domestic microwave appliance for heating food placed in it, since the appliance does not inform him of an incipient reduction in performance. In particular, repeated preparation of dishes of the same type or dishes with the same quantity leads to unequal heating results with the same set time ("running time") and the same set microwave power, since subsequent dishes may only be heated with reduced microwave power compared to previous dishes became. In particular, it can happen that a user has to heat food again using microwaves after the set run time has elapsed in order to obtain a desired degree of heating.

EP 1 594 345 B1 discloses a microwave appliance or a combination cooking appliance with microwave operation, comprising: a) at least one cooking compartment, b) at least one device for generating microwaves, c) one or more temperature sensors, in particular for detecting the cooking compartment temperature and/or for detecting the temperature of the device for generating of microwaves, with each of the temperature sensors generating a measurement signal, and d) at least one evaluation device with which the load status of the cooking chamber, in particular an idle operation of the microwave device, can be determined on the basis of the development over time of the measurement signal of at least one of the temperature sensors during microwave operation.

DE 10 2014 217 637 A1 discloses a method for heating a cooking chamber (2) of a household cooking appliance, the cooking chamber (2) being heated during an initial cooking phase (GP) with an unregulated input heating power (P1, P2) and then during a regulating phase (RP ). the second section (A2) at least one property of the introduced heating power (P1, P2) is changed. A household cooking appliance (1) has a cooking chamber, at least one heating device (5, 6, 9) for heating the cooking chamber (2), a temperature detection device (12) and a control device connected to the at least one heating device and to the temperature detection device (12). (14), the control device (14) being set up to run the method (GP, RP) on the cooking appliance (2).

DE 10 2013 201 070 A1 discloses that in a method for controlling a cooking appliance, for example a hob, a cooking process is selected by an operator on a controller of the cooking appliance, with different parameters for this cooking process being present in the controller. Depending on the cooking process and the respective item to be cooked, the controller determines a maximum operating time for the cooking appliance and after this maximum operating time has elapsed, it switches off the cooking appliance or a functional unit for preparing the item to be cooked. A safety function against forgetting to switch off the cooking appliance can thus be created.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide a possibility for household microwave devices, to facilitate their use and to increase user satisfaction.

This object is solved according to the features of the independent claims. Advantageous embodiments are the subject matter of the dependent claims, the description and the drawings.

1. a) aus mindestens einer Nutzereinstellung, die zumindest eine Mikrowellen-Sollleistung umfasst, für einen Mikrowellen-Heizvorgang eine zugehörige Mikrowellen-Gesamtenergie bestimmt oder berechnet wird,
2. b) beruhend auf mindestens einer Sensorinformation und der eingestellten Mikrowellen-Sollleistung ein zeitlicher Verlauf einer für den Mikrowellen-Heizvorgang zukünftigen abrufbaren Mikrowellen-Verfügungsleistung bestimmt wird,
3. c) beruhend auf dem zeitlichen Verlauf der Mikrowellen-Verfügungsleistung ein zukünftiger zeitlicher Verlauf der tatsächlich einzuspeisenden Mikrowellenleistung (auch als „Mikrowellen-Istleistung“ bezeichnet) bestimmt wird, der die zugehörige Mikrowellen-Verfügungsleistung zu keinem Zeitpunkt überschreitet und die gleiche Mikrowellen-Gesamtenergie wie die aus den Nutzereinstellungen bestimmte Mikrowellen-Gesamtenergie aufweist, und
4. d) aus dem Verlauf der tatsächlich einzuspeisenden Mikrowellenleistung eine Restlaufdauer des Mikrowellen-Heizvorgangs bestimmt wird.

The object is achieved by a method for operating a household microwave appliance, having a microwave generator for generating microwaves, a treatment chamber that can be acted upon by the microwaves, and at least one sensor for detecting at least one item of sensor information, in which method

1. a) an associated total microwave energy for a microwave heating process is determined or calculated from at least one user setting, which includes at least one microwave target power,
2. b) based on at least one item of sensor information and the set microwave target power, a time profile of a future available microwave power that can be called up for the microwave heating process is determined,
3. c) based on the time profile of the available microwave power, a future time profile of the microwave power actually to be fed in (also referred to as "actual microwave power") is determined, which at no time exceeds the associated available microwave power and has the same total microwave energy as the has total microwave energy determined from user settings, and
4. d) a remaining duration of the microwave heating process is determined from the course of the microwave power actually to be fed in.

One advantage of the method is that the remaining running time can be calculated particularly precisely on the basis of the at least one piece of sensor information. This in turn makes it easier for a user to use the household microwave device and increases user satisfaction.

In addition, due to the use of the sensor information to calculate the available microwave power, no large thermal safety margins need to be maintained, which enables a particularly high available microwave power, and it is nevertheless prevented in a particularly reliable manner that the household microwave appliance reaches or exceeds safety-relevant thermal limit values . This is in particular in contrast to the case in which the available microwave power is only determined based on a setting variable such as the set microwave target power and thus its progression without taking into account changes in operation (such as a change in temperature of components or the ambient air drawn in), environmental variables, etc .

The available microwave power represents, in particular for a point in time, a maximum available upper limit for the microwave power actually to be fed in at that point in time. The course of the available microwave power over time corresponds analogously to a curve which, for each point in time, represents an upper limit of the microwave power actually to be fed in at that point in time is equivalent to. The available microwave power is calculated in advance and not built up from historical data.

In the present method, in particular the at least one piece of sensor information and the set microwave target power can be determined several times in succession (e.g. in predetermined fixed or variable time steps, e.g. every 0.1 s, every 1 s, etc.) and the time profile of the microwave Disposal performance are recalculated in each case. In this way, for example, reductions in the microwave power that is actually to be fed in can be limited to situations in which this reduction is actually necessary. For example, if a microwave available power (e.g. recalculated) that is below the actually fed-in microwave power, the actual microwave power can be automatically reduced to the level of this microwave available power, or to an even lower level. It is also possible to react to situations in which the available microwave power increases, which can shorten the remaining service life. In both situations it is assumed that the microwave power actually fed in is set on the device side in such a way that it practically does not exceed the available microwave power (possibly also newly calculated) at a given point in time. The term "practically not exceeding" means in particular that the actual microwave power is only adjusted to a reduced available microwave power after a short adjustment period of the microwave generator, with this adjustment period being so short that it affects the operation of the household microwave oven and the treatment result has no practical impact.

The setting of the target microwave power can be a setting of explicit power values (e.g. in steps of 600 W, 700 W, 800 W, 900 W, etc. or practically continuously) or corresponding settings ("low", "medium", "high", etc.).

The fact that in step c) a future time profile of the microwave power actually to be fed in is determined "based" on the time profile of the available microwave power can also be expressed in such a way that the time profile of the microwave power actually to be fed in is "taking into account" the time profile of the microwaves -Availability is determined. This includes that in a further development, the time profile of the actual microwave power to be fed in can also be determined or set using further information or specifications in addition to the available microwave power, which can lead, for example, to the fact that it can at least temporarily be lower than the time Course of the maximum available microwave power.

Alternatively or additionally, the time profile of the available microwave power can also be calculated using further information or specifications in addition to the sensor information, setting information and status information.

In general, however, the household microwave appliance can also be operated in a development such that the predicted time profile of the microwave power to be fed in or the actual microwave power corresponds to the predicted microwave power available, in particular over the entire duration of a microwave heating process. In other words, the household microwave appliance can be set up to set the actual microwave power currently being fed in only in accordance with the predicted time profile of the available microwave power.

The fact that in step c) the time profile of the actual microwave power is determined in such a way that it has the same (integral) total microwave energy as the total microwave energy determined from the user settings includes in particular that the time profile of the actual microwave power is determined in this way that the microwave heating process is interrupted or ended (e.g. the progression of the actual microwave power is reduced to zero) when the total microwave energy predetermined in step a) has been fed into the treatment room.

The fact that in step d) a remaining period of time "remaining duration" of the microwave heating process is determined from the course of the microwave power actually to be fed in, includes in particular the concrete determination or calculation of the point in time or the period of time at which the microwave heating process is interrupted or ended, because the predetermined total microwave energy has been reached. Since the course of the microwave power actually to be fed in is calculated in advance, the remaining service life can also be calculated in advance with a high level of accuracy.

A microwave heating process can be understood in particular as a user-initiated heating process for heating food or the like accommodated in a treatment space of the microwave device. The microwave heating process can be started, for example, by pressing a start button or by closing a door of the treatment room, etc.

Sensor information can be understood in particular as a measured value from a sensor or a value derived therefrom.

It is a further development that the at least one user setting additionally includes a setting of a user-desired runtime of the microwave heating process. The running time can be stated directly (e.g. as an indication in seconds and/or minutes) or indirectly (e.g. as "short", "medium", "long" etc. or in the form of other relative indications such as an indication of a specific number of time slots from a group with a predetermined maximum possible number of time slots). The user does not need to know the length of time associated with a time slot. These time slots can, for example, be referred to as “energy points” or something similar. A user can thus indirectly set a desired runtime of the microwave heating process—and without precise knowledge of the total time associated therewith—by setting, for example, 14 energy points from a maximum of 20 possible energy points.

It is also possible for a user not to set a running time, but rather to specify a specific cooking program that specifies the running time for the microwave heating process without taking into account the available microwave power. The precise calculation of the remaining running time by the present method can be used advantageously when using a cooking program, for example - optionally also without displaying a remaining running time - to inform a user about the imminent end of the microwave heating process before the remaining running time has expired, for example by means of an optical message and/or acoustic notification. In one development, a user can set the desired microwave power in the cooking program indicate, if necessary indirectly by information such as "strong", "medium", "gentle" etc.

The fact that the total microwave energy is determined or calculated on the basis of user settings in step a) can in particular include the total microwave energy being calculated from the microwave setpoint power and a preset or predetermined runtime for the microwave heating process. The total microwave energy thereby corresponds to an amount of energy or an "energy equivalent" that a user would like to achieve by adjusting the user settings. The total microwave energy can then be calculated, for example, by simply multiplying the set microwave target power by the preset transit time.

The household microwave oven can be a stand-alone microwave oven or a combination microwave oven (such as an oven/microwave combination oven, etc.).

The microwave generator may be a magnetron, e.g., driven by an inverter, or a semiconductor microwave generator. The microwaves generated by the microwave generator can be radiated or fed into the treatment room, directly or via a microwave guide.

The treatment room can be set up or provided for serving food and can also be referred to as a food treatment room or cooking room.

In one configuration, the remaining running time is displayed in a display device. As a result, the end of the microwave heating process can be communicated to a user in a particularly easy-to-understand and user-friendly manner with particularly high accuracy. The remaining running time comprises in particular an initial remaining running time before or at the beginning of the microwave heating process as well as a remaining remaining running time counted down during operation. The remaining running time corresponds in particular to the difference between the initial remaining running time and the time that has already elapsed for the microwave heating process.

The display device can be, for example, a screen, a touch-sensitive screen (“touch screen”), a segment display, etc.

In one development, a continuous microwave power represents a lower limit for the available microwave power. The microwave continuous power can be understood to mean a microwave power which is dimensioned in such a way that it can be permanently maintained without one or more appliance components of the household microwave appliance overheating.

In one embodiment, the at least one user setting includes a predetermined runtime of the microwave heating process (i.e., a runtime that has been set by a user) and that if the calculated remaining runtime exceeds the predetermined runtime, a query is made as to whether the calculated remaining running time is to be set as the new specified running time. In this way, the advantage is achieved that a user has the option of either sticking with his predefined runtime or alternatively setting the calculated remaining runtime as the runtime of the microwave heating process. This embodiment thus includes in particular that a user can confirm that he accepts the determined or calculated remaining running time as the new or changed running time of the microwave heating process (for example by pressing a corresponding button to start the microwave heating process without rejecting a takeover) or alternatively the accepting the remaining running time as the new running time or rejecting it (e.g. by pressing a corresponding button or by starting the microwave heating process without confirming acceptance). If the calculated remaining time is accepted as the new time for the microwave heating process, the microwave heating process ends when the remaining time is reached. If the transfer is rejected, the microwave heating process ends when the originally set runtime is reached.

In one configuration, the at least one user setting includes a specified runtime of the microwave heating process and then, if the calculated remaining runtime exceeds the specified runtime, the remaining runtime automatically, i. i.e. it is set as the new runtime without any further user queries. In this way, a particularly convenient option is advantageously achieved for setting a correct remaining running time for achieving a desired cooking result, since the user no longer has to worry about comparing the remaining running time with the running time originally specified by him.

It is a development that the user can choose between a query to accept the remaining term as the new term and an automatic transfer. It is a further development that the user can optionally activate and deactivate or switch on and off the query for taking over the remaining term as the new term as well as the automatic acceptance.

In one embodiment, when at least one user setting is changed and/or at least one piece of sensor information changes, the remaining running time is redetermined and adjusted automatically, ie without further user query. This embodiment includes, in particular, that both the initial remaining running time and a remaining running time during the microwave heating process are automatically adjusted. The automatic adjustment can in particular include the newly determined or calculated remaining term being automatically set as the new remaining term or term and in particular also being displayed if it differs from the currently set remaining term.

It is also a further development that if the remaining running time changes while the microwave heating process is running (e.g. if at least one user setting is changed and/or at least one piece of sensor information changes) and the specified running time is exceeded or not reached, a query is made as to whether the remaining term is to be set as the new term. This opens up a further possibility for a user to set the duration of the microwave heating process in a targeted manner. In other words, the acceptance of a changed remaining running time as the new (remaining) running time can also be queried during a microwave heating process. If the changed remaining term is not accepted as the new term, the old term will be retained.

In one configuration, a user can selectively activate or deactivate the display of the calculated remaining running time. This allows a user to decide whether or not to use the sensor-based, automatically calculated remaining running time display. This can be advantageous if a user wants to make a particularly simple entry on the household microwave appliance. In a further development, the user can also optionally activate or deactivate the calculation of the remaining running time as such. A user can activate and deactivate e.g. in the basic settings of a user menu. The calculation of the time profile of the microwave power actually to be set as described above, taking into account the available microwave power, remains in place or is active as a further development in order to be able to utilize the thermal reserves of the household microwave appliance particularly effectively.

In one embodiment, the time profile of the available microwave power is determined based on a calculation model (hereinafter referred to as “thermal equivalent model” without loss of generality) for the household microwave appliance. The thermal equivalent model has the advantage that the available microwave power can be brought up to the thermal limit temperatures of the system components of the household microwave appliance or to individual components thereof with particularly high accuracy, without exceeding their limit temperatures. In particular, the thermal equivalent model depicts all the essential heat capacities and heat transfer resistances of appliance components of the household microwave appliance. In this way, a heat capacity of the device components and their cooling ability can be calculated using theoretical considerations (e.g. including masses and heat transfer resistances). The theoretical considerations can be verified by laboratory measurements. In this way, the equivalent thermal model is prepared device-specifically in such a way that only at least one piece of sensor information from the ongoing operation of the household microwave device is required to precisely predict the thermal reserve that is still available (the thermal capacity that can still be used) of the device components for a specific microwave target power. Such considered device components can include, for example, a switched-mode power supply (inverter) for operating a microwave generator, power supply lines, fuses and switching devices (relays) as well as mains filter devices for mains interference suppression. The device components can in turn consist of individual components that heat up differently, which often also have different thermal loads, for example different operating limit temperatures. The thermal equivalent model can take into account both the device components and, if necessary, the associated components individually. The device components are mainly cooled by heat convection using cooling air and by heat conduction to reduce heat.

In one development, the at least one item of sensor information includes at least one item of temperature information. This is particularly advantageous since temperature information can give a particularly reliable indication of thermal reserves that are still present and thus of a microwave power available. However, the sensor information can also include information about other physical variables such as humidity, speed, and so on.

• - Luftansaugtemperatur von angesaugter Umgebungsluft;
• - Luftausblastemperatur;
• - Temperatur des Behandlungsraums;
• - Temperatur mindestens eines Gerätezwischenraums;
• - Temperatur mindestens einer Gerätekomponente, z.B. eines Inverters;
• - Feuchtigkeit in dem Behandlungsraum;
• - Feuchtigkeit der Umgebungsluft;
• - Ist-Drehzahl eines (Kühl-)Lüfters;

umfasst.In one configuration, the at least one item of sensor information is at least one item of sensor information from the group

• - Air intake temperature of intake ambient air;
• - air discharge temperature;
• - temperature of the treatment room;
• - Temperature of at least one space between the devices;
• - Temperature of at least one device component, eg an inverter;
• - humidity in the treatment room;
• - humidity of the ambient air;
• - Actual speed of a (cooling) fan;

includes.

This sensor information can give a particularly reliable indication of thermal reserves that are still present and thus open up the possibility of determining the remaining service life particularly precisely. An air intake temperature can be understood in particular as the temperature of the ambient air or of ambient air or cooling air sucked into the microwave device. Their temperature level has a particularly strong influence on the heat dissipation of the device components. An air blow-out temperature can be understood to mean the temperature of air which is blown out from the microwave device into the environment. The temperature of the treatment room can also be referred to as cooking room temperature or treatment temperature. The device component can be an inverter, for example. A space between the devices can be understood to mean a space between the treatment space and an outer housing of the microwave device. The space between the devices can be, for example, a control room or electronics room, in which the electrics or electronics of the microwave device, possibly including a magnetron and/or a switched-mode power supply unit (for example an inverter circuit) are accommodated. The sensor information can be measured, for example, by corresponding temperature sensors, humidity sensors, speed sensors, etc. and can also be referred to as temperature, humidity, speed readings, etc. or temperature, humidity, speed data, etc.

In one development, the fan is a cooling fan, an electronics fan, a magnetron fan and/or an inverter fan.

In one configuration, the available microwave power is additionally determined on the basis of at least one piece of setting information that is automatically set on the device side.

In this way, the time course of the thermal reserve and thus the available microwave power and the remaining service life can be determined even more precisely. Setting information can be understood in particular as a set value from a group of multiple automatically settable values of at least one device parameter and/or at least one settable device component. An adjustable value can also be zero.

• - Soll-Lüfterdrehzahl;
• - Winkelstellung mindestens einer Klappe, z.B. Lüftungsklappe, z.B. Wrasenklappe; umfasst.

In one configuration, the at least one item of setting information is at least one item of setting information from the group

• - Desired fan speed;
• - Angular position of at least one flap, eg ventilation flap, eg vapor flap; includes.

The setting information makes it possible to calculate the thermal reserves that are still available and thus the course of the microwave power available and the remaining service life even more precisely. In particular, the fan speed gives an indication of the strength of a heat dissipation and thus of the temporal behavior of the thermal reserves. The fan speed is particularly variable and can itself be dependent on a temperature measurement.

In one development, the fan speed includes a target fan speed of a device fan, a fan speed of an electronics fan, a fan speed of a magnetron fan and/or a fan speed of an inverter fan.

In one configuration, the available microwave power is additionally determined on the basis of at least one item of status information, in particular an activity status. This can also advantageously provide a reliable indication of thermal reserves that are still present.

In a further development, the activity status includes at least the statuses “on”/“off”, “open”/closed” or “in operation”/“paused” (“pause” status). If, for example, a microwave heating process is paused it has hitherto been practically impossible for a user to take into account the heat dissipation of device components that occurs during a pause, while in the present case this heat dissipation can be precisely taken into account for determining the thermal reserve. Other status information can include, for example, an open or closed status of a flap, door, valve, etc.

The sensor information, setting information, status information and possibly further specifications or information can also be referred to together as device information.

The available microwave power, in particular its progression over time, can be calculated in a particularly reliable and precise manner based at least on at least one item of temperature information and the desired microwave power.

In one configuration, only those desired microwave powers can be selected for a microwave heating process which do not exceed the current available microwave power. This reliably prevents the domestic microwave oven from overheating or a safety shutdown or safety limit from occurring. For example, if a user wants to set a target microwave power (e.g. 900 W) that is not available according to the calculation of the available microwave power (but only a maximum of 800 W, for example), he cannot select it. This can be implemented, for example, by the fact that the desired microwave target power is not even offered for setting.

In a further development, in step c) the curve of the microwave power actually to be fed in is additionally determined or set such that it (not based on the equivalent thermal model) has specified power changes, in particular power reductions or drops in power. This achieves the advantage that a cooking result can be improved. A specified power change can, for example, include a point in time from the onset and possibly the end of the power change and a size of the power change. The magnitude of the change in performance may include a change by a specific magnitude or a change to a predetermined level of performance. The power change can be specified by the household microwave oven, e.g. from a cooking program.

In one embodiment, in step c) the profile of the microwave power actually to be fed in is additionally determined or adjusted in such a way that it automatically exhibits a defined power drop from a predetermined point in time of the microwave heating process. In this way, for example, the probability can be reduced that foodstuffs exposed to microwaves will splatter hot water, overcook, etc. The defined drop in power can in principle also be applied without calculating the available microwave power and represents an independent inventive idea.

Alternatively or additionally, the specified power change can also be specified when calculating the time profile of the available microwave power in step b), the time profile of the available microwave power can also be calculated using predefined power changes that do not result from the equivalent thermal model . In this case in particular, it can be advantageous for the time profile of the microwave power actually to be fed in until the end of a microwave heating process to follow the time profile of the available microwave power, which has already been adapted to the predefined power change(s). .

The object is also achieved by a household microwave device that is set up to carry out a method as described above. The household microwave device can be designed analogously to the method and has the same advantages.

• - einen Behandlungsraum;
• - einen Mikrowellengenerator zum Erzeugen von Mikrowellen;
• - mindestens einen Sensor zum Erfassen mindestens einer Sensorinformation aufweist;
• - eine Eingabeeinheit zum Eingeben zumindest der Mikrowellen-Sollleistung; und
• - mindestens eine Anzeigeeinrichtung zum Anzeigen zumindest der Restlaufdauer aufweist.

It is an embodiment that the household microwave device at least:

• - a treatment room;
• - a microwave generator for generating microwaves;
• - Has at least one sensor for detecting at least one piece of sensor information;
• - an input unit for inputting at least the desired microwave power; and
• - Has at least one display device for displaying at least the remaining running time.

• - eine mit einem Datenspeicher gekoppelte Datenverarbeitungseinrichtung, wobei in dem Datenspeicher Software (z.B. umfassend Daten und/oder Instruktionen) gespeichert ist, welche die Datenverarbeitungseinrichtung dazu einrichtet, den zeitlichen Verlauf der Mikrowellen-Verfügungsleistung, den zeitlichen Verlauf der einzuspeisenden Mikrowellen-Istleistung und die Restlaufdauer zumindest aus der mindestens einen Sensorinformation und der Mikrowellen-Sollleistung als Eingangsgrößen zu bestimmen und
• - eine Steuereinrichtung zum Betreiben des Mikrowellengenerators anhand des bestimmten zeitlichen Verlaufs der Mikrowellen-Istleistung bis zum Erreichen der Restlaufdauer.

It is an embodiment that the household microwave oven also has:

• - A data processing device coupled to a data storage device, with software (e.g. comprising data and/or instructions) stored in the data storage device, which the data processing device sets up to record the time profile of the available microwave power, the time profile of the actual microwave power to be fed in and the remaining running time to be determined at least from the at least one piece of sensor information and the desired microwave power as input variables, and
• - A control device for operating the microwave generator based on the determined time profile of the actual microwave power until the remaining running time is reached.

The data memory can be in the household microwave device or an external data memory that can be coupled to the household microwave device in terms of data technology.

The data processing device can include a microprocessor, ASIC, FPGA, etc. The data storage device can be integrated into the data processing device or can be linked to the data processing device as a separate data storage device.

The control device can be a device that is different from the data processing device, or the data processing device can be integrated into the control device. The control device is set up in particular to generate the microwaves by carrying out the method described above, e.g. by means of suitable control software, e.g. to control the microwave generator, e.g. an inverter thereof.

• 1 zeigt als teilweise Schnittdarstellung in Frontansicht ein erfindungsgemäßes Haushalts-Mikrowellengerät;
• 2 zeigt eine Auftragung von mit dem Verfahren zusammenhängenden Mikrowellenleistungen für einen ersten Mikrowellen-Heizvorgang;
• 3 zeigt eine Auftragung von mit dem Verfahren zusammenhängenden Mikrowellenleistungen für einen zweiten Mikrowellen-Heizvorgang;
• 4 zeigt eine Auftragung von mit dem Verfahren zusammenhängenden Mikrowellenleistungen für einen dritten Mikrowellen-Heizvorgang; und
• 5 zeigt eine Auftragung von mit dem Verfahren zusammenhängenden Mikrowellenleistungen für einen vierten Mikrowellen-Heizvorgang.

The characteristics, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a household microwave appliance according to the invention as a partially sectional representation in front view;
• 2 Figure 12 shows a plot of process-related microwave powers for a first microwave heating operation;
• 3 Figure 12 shows a plot of process-related microwave powers for a second microwave heating process;
• 4 Figure 12 shows a plot of process-related microwave powers for a third microwave heating event; and
• 5 Figure 12 shows a plot of process-related microwave powers for a fourth microwave heating event.

1 shows a partially sectional front view of a household microwave appliance 1 according to the invention with a treatment chamber 2, a microwave generator 3, 4 with an inverter 3 and a magnetron 4 that can be operated by the inverter 3 for generating microwaves, a wave guide 5 for conducting the microwaves from the magnetron 4 in the treatment room 2 and a control device 6 for controlling the inverter 3. Purely by way of example, a continuous microwave power of 600 W and a maximum achievable microwave power of 900 W available.

The household microwave appliance 1 also has a user interface 7 , 8 which has a display device 7 and one or more input fields 8 . A user can use the at least one input field 8 to set, for example, a desired desired microwave power Ps and a desired runtime ts for a microwave heating process. The display device 7 and the at least one input field 8 can be integrated in a touch-sensitive screen (“touch screen”). The user interface 7, 8 is coupled to the control device 6.

The household microwave appliance 1 also has at least one sensor, e.g on the inverter 3 or an electronics compartment containing the inverter 3 (not illustrated) and a speed sensor 13 for sensing a speed Uactual of the cooling fan 10. The speed Uactual can deviate from a target speed Usoll automatically set on the device. The temperature sensors 9 and 11, the speed sensor 13 and the cooling fan 10 are also coupled to the control device 6 .

Software that sets up the control device 6 to carry out the method described above can run on the control device 6 . The software can be stored in a data memory 12 integrated into the control device 6, for example. The software can set up the control device 6, for example, to calculate the total microwave energy from the microwave setpoint power Ps and the transit time ts. The software can also set up the control device 6 to generate a time profile of a microwave available power Pv at least from the sensor information T1, T2, Uactual, the setting information Usoll, possibly status information and/or other information, as well as from the set microwave setpoint power Ps to determine or to calculate and from this to determine or to calculate the time profile of the actual microwave power Pm to be actually fed in as well as the remaining running time tr. A function of a data processing device for determining the time profile of the available microwave power Pv, the time profile of the actual microwave power Pm and the remaining running time tr is integrated into the control device 6 .

2 shows a plot of the microwave power P associated with the method in watts [W] versus time t in seconds [s], namely the microwave target power Ps set by the user, the for this microwave target power Ps calculated, maximum achievable time profile of the available microwave power Pv and a calculated and generated profile of the microwave power Pm actually to be fed in for a first microwave heating process. The microwave setpoint power Ps is a user setting and is entered via the user interface 7, 8, here for example as Ps=900 W. The user can also use the user interface 7, 8 to specify a user setting in the form of the runtime ts, here for example 60 s .

The control device 6 calculates the total microwave energy E=Ps·ts=54 kW s desired by the user from the desired microwave power Ps and the transit time ts by simple multiplication. However, other calculation rules can also be used.

The control device 6 also uses the thermal equivalent model and at least the above-described device information T1, T2, Uactual, Usoll and the microwave target power Ps as input parameters to calculate the time profile of the available microwave power Pv for the desired microwave target power Ps. It exceeds the microwaves -The available power Pv does not exceed the target microwave power Ps. In particular, the control device 6 only uses the set speed Usoll of the cooling fan 10 as an input variable for the thermal equivalent model if no measured speed Uactual is available.

In the present exemplary embodiment, the control device 6 has calculated from the equivalent thermal model that an available microwave power of 900 W can be maintained for 70 seconds without thermal overload before it has to be reduced by 100 W to 800 W. Consequently, the desired microwave power Ps set by the user can actually be made available for the entire set runtime ts.

The control device 6 then determines a time profile of the actual microwave power Pm (actual microwave power) to be fed in, which follows the profile of the predicted available microwave power Pv of 900 W until the total microwave energy E of 54 kW s after ts = 60 s has been reached. The microwave heating process is then terminated by reducing the actual microwave power Pm to zero.

In this exemplary embodiment, the remaining running time tr therefore corresponds to the set running time ts, which does not need to be adjusted. Accordingly, the associated microwave heating process can be performed as set.

3 shows a plot of the microwave setpoint power Ps set by the user, the calculated profile of the available microwave power Pv and the calculated and generated or to be generated profile of the microwave power Pm actually to be fed in for a second microwave heating process. The user settings Ps and ts correspond to those of the first microwave heating process 2 .

The case here is that the time profile of the available microwave power Pv shows that the microwave power Pm actually to be fed in can initially be maintained at the set microwave target power Ps of 900 W for 10 s, but then for thermal reasons must be reduced, namely in a period between 10 s and 40 s to a maximum level of 800 W and then for at least 30 s to a level of only 700 W which, from the point in time t=10 s after the start of the microwave heating process, the available microwave power Pv is below the set microwave target power Ps.

The control device 6 uses the curve of the available microwave power Pv to calculate a time curve of the microwave power Pm actually to be fed in, which follows the curve of the predicted available microwave power Pv until the total microwave energy E of 54 kW s has been reached. The microwave heating process is then terminated at the corresponding remaining running time tr. In the present exemplary embodiment, the calculated remaining running time tr is 70 s and thus 10 s more than the running time ts set by the user.

Since the total microwave energy E and the available microwave power Pv and thus also the remaining running time tr are precalculated by the control device 6, the remaining running time tr can be displayed to a user on the display device 7 before the start of the microwave heating process. The user can now be given the opportunity via the user interface 7.8 to accept the calculated remaining term tr as the new term ts, or not. Alternatively, the calculated remaining term tr can be automatically adopted as the new term ts.

If the calculated remaining running time tr is accepted as the new running time ts automatically or after a query, the treatment room 2 is subjected to a microwave power Pm that follows the curve of the available microwave power Pv for tr=70 s and is then switched off. If the calculated remaining term tr is not used as the new run Taken over time ts, the treatment room 2 is subjected to a microwave power Pm which follows the course of the available microwave power Pv for 60 s, ie for the originally set running time ts, and is then switched off. With or without taking over the remaining running time tr as the new running time ts, the course of the microwave power Pm is set in such a way that at any point in time the available microwave power Pv applicable to that point in time is not exceeded. The course of the available microwave power Pv thus represents an upper limit for the microwave power Pm actually fed in for the entire microwave heating process. At the start of the microwave heating process, the remaining running time tr is reduced accordingly.

A user can also select via the user interface 7.8 whether he would like to permanently deactivate or turn off or activate the option of taking over the remaining term tr as the new term ts.

If a user now wants to start another microwave heating process, even though the household microwave appliance 1 has not yet cooled down or cooled down, it can happen that the set microwave power Ps is already above that for the further microwaves from the start -heating process recalculated available microwave power Pv. This can be the case here, for example, if a user wants to start a microwave heating process again with the same user settings of Ps = 900 W and ts = 60 s, for example if he wants to microwave several of the same dishes in quick succession. In a further development, the household microwave appliance 1 can only allow input of a desired microwave power Ps for the further microwave heating process, which does not exceed the currently available microwave power Pv of 700 W here. The desired total microwave power E is then calculated on the basis of a lower target microwave power Ps. Alternatively, the household microwave device can accept the actually unachievable microwave setpoint power Ps and calculate the total microwave energy E on this basis.

4 shows in more detail the case of the further microwave heating process with the same user settings Ps = 900 W and ts = 60 s, which is directly related to the in 3 described microwave heating process connects. Since the household microwave appliance 1 was not able to cool down significantly before the further microwave heating process, the control device 6 has calculated that a maximum microwave power Pv of 700 W can be made available at the beginning of the further microwave heating process. Furthermore, the calculated time profile of the available microwave power Pv shows that it drops again by 100 W after 60 s, to a permanently available microwave power of 600 W.

In order to be able to apply the desired total microwave energy E of 54 kW s to the food in the treatment room 2, the actual microwave power Pm to be fed in must follow the curve of the available microwave power Pv for 80 s. In this case, the remaining running time tr is 80 s. Otherwise, the course can be analogous to 3 expire.

5 shows a plot of the desired microwave power Ps, the calculated time profile of the available microwave power Pv and the calculated and generated profile of the microwave power Pm actually to be fed in. The user settings Ps = 900 W and ts = 60 s correspond to those of the second microwave heating process, purely as an example 3 .

In contrast to 3 the course of the microwave power Pm actually to be fed in now deviates from the course over time of the maximum achievable available microwave power Pv, namely in that the microwave power Pm has been subjected to a defined drop in power to 600 W from t=60 s. To achieve the desired total microwave energy E of 54 kW s, this results in a remaining running time tr at the start of the microwave heating process of approximately 72 s. Such a reduction can be made, for example, to improve the cooking result.

In a further development, this defined drop in power can be carried out independently of the calculation of the time profile of the available microwave power Pv. Since the remaining running time tr is calculated from the calculated time profile of the microwave power Pm that is actually to be fed in, the defined drop in power is taken into account in its calculation.

Alternatively, the defined drop in power can already be taken into account when calculating the time profile of the available microwave power Pv (not shown). The time profile of the microwave power Pm actually to be fed in up to the end of the microwave heating process can then follow the time profile of the available microwave power Pv, which has already been adapted to the predefined power change(s). The calculation of the remaining service life tr also takes into account the defined drop in performance.

Of course, the present invention is not limited to the embodiment shown.

If at least one user setting is changed and/or at least one piece of sensor information changes, the remaining running time can be generally redetermined and e.g. automatically adjusted.

In general, "a", "an" etc. can be understood as a singular or a plural number, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly a" etc.

A numerical specification can also include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

Reference List

1

household microwave oven

2

treatment room

3

inverters

4

magnetron

5

waveguide

6

control device

7

display device

8th

input box

9

temperature sensor

10

cooling fan

11

temperature sensor

12

data storage

13

speed sensor

E

Total Microwave Energy

P

microwave power

pm

Actual Microwave Power

p.s

Set microwave target power

pv

Microwave power available

t

Time

tr

remaining term

ts

Set runtime

T1

Ambient air temperature

T2

Inverter temperature

A

ambient air

usol

Set speed of the cooling fan

Uist

Measured speed of the cooling fan

Claims (14)

Method for operating a household microwave appliance (1), having a microwave generator (3, 4) for generating microwaves, a treatment chamber (2) which can be acted upon by the microwaves and at least one sensor (9, 11, 13) for detecting at least one item of sensor information ( T1, T2, Uactual), with which method a) an associated microwave total energy (E) for a microwave heating process is determined from at least one user setting (Ps, ts), which includes at least one microwave setpoint power (Ps), b) based on at least one piece of sensor information (T1, T2, Uactual) and the set microwave target power (Ps), a time profile of a microwave available power (Pv) that can be called up in the future for the microwave heating process is determined, c) based on the time profile of the available microwave power (Pv), a time profile of the microwave power (Pm) actually to be fed in is determined, which at no time exceeds the associated available microwave power (Pv) and has the same total microwave energy (E) as has the total microwave energy (E) determined from the user settings (Ps, ts), and d) a remaining duration (tr) of the microwave heating process is determined from the course of the microwave power (Pm) actually to be fed in. procedure after claim 1 , in which the remaining running time (tr) is displayed in a display device (7). procedure after claim 2 , in which the at least one user setting (Ps, ts) also includes a user-set runtime (ts) of the microwave heating process and then, if the specific remaining runtime (tr) exceeds this runtime (ts), it is queried whether the remaining runtime (tr ) is to be set as a new default runtime (ts). procedure after claim 2 , in which the at least one user setting (Ps, ts) includes a predetermined runtime (ts) of the microwave heating process and then, if the determined remaining runtime (tr) exceeds the predetermined runtime (ts), the remaining runtime (tr) automatically as the predetermined one Running time (ts) is set. Procedure according to one of claims 2 until 4 , in which the display of the remaining running time (tr) and/or the determination of the remaining term (tr) can be switched off by the user. procedure after claim 3 , in which the query as to whether the remaining term (tr) should be set as the term (ts) can be switched off by the user. Method according to one of the preceding claims, in which the at least one piece of sensor information is at least one piece of sensor information (T1, T2, Uactual) from the group - air discharge temperature; - Temperature in the treatment room (2); - Temperature of a device space, in particular switch room and / or electronics room; - Temperature (T2) of at least one device component (3); - Actual speed (Uist) of a cooling fan (10); includes. Method according to one of the preceding claims, in which the available microwave power (Pv) is additionally determined on the basis of at least one item of setting information (Usoll) that is automatically set on the device side. procedure after claim 8 , in which the at least one item of setting information (Usoll) is at least one piece of setting information from the group - fan speed, in particular target fan speed (Usoll) of a cooling fan (10), an electronic fan, a magnetron fan and/or an inverter fan; - Angular position of at least one flap includes. Method according to one of the preceding claims, in which the available microwave power (Pv) is additionally determined on the basis of at least one item of status information, in particular an activity status. Method according to one of the preceding claims, in which if at least one user setting (Ps, ts) is changed and/or at least one piece of sensor information (T1, T2, Uist) changes, the remaining running time (tr) is redetermined and automatically adjusted or it is queried whether the remaining running time (tr) should be set as the new running time (ts). Method according to one of the preceding claims, in which only those desired microwave powers (Ps) can be selected for a microwave heating process which do not exceed a current available microwave power (Pv). Method according to one of the preceding claims, in which in step c) the profile of the microwave power (Pm) actually to be fed in is additionally determined such that it has a defined power drop from a predetermined point in time of the microwave heating process. Household microwave oven (1), which is set up to carry out a method according to one of the preceding claims.

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