DE102012222144A1 - Method for controlling outlet of cooking appliance, involves determining maximum value of temperature difference for measuring core temperature of food, by determining gradient of temperature difference of temperature sensors - Google Patents

Abstract

The method involves determining the course of the temperature difference to determine a maximum value of the temperature difference for measuring core temperature of food, by determining gradient of temperature difference of temperature sensors (11). The temperature difference is compared with threshold value corresponding to desired cooking state. Independent claims are included for the following: (1) cooking appliance; and (2) device for controlling cooking appliance.

Description

The invention relates to a method for controlling a cooking cycle by determining a course of a temperature difference of at least two temperature sensors of a core temperature sensor. The invention further relates to an apparatus for carrying out the method.

Core temperature sensor or Garprozessfühler be used to determine a core temperature of a food or food, especially pieces of meat, when cooking in an oven. Core temperature sensors are known which have a plurality of temperature sensors or measuring points in their sensor tube. These are used to compensate for mishaps in which the temperature sensor is not located exactly in the core of the food.

It is also known to automatically detect a cooking time end by prescribing a desired core temperature corresponding to a desired state of cooking, e.g. for beef about 50 ° C for 'English', about 60 ° C for 'medium' and about 70 ° C for 'cooked through'. When the setpoint core temperature is reached, the cooking process is automatically terminated by an oven connected to the core temperature sensor and this is signaled to the user. However, in this case it is disadvantageous that the desired core temperature often does not correspond to the desired state of cooking.

From the DE 299 23 215 U1 a core temperature sensor for controlling a cooking process is known, which is at least partially plugged into a food and with the at least two temperature values can be detected, on the thermokinetics of the detected temperature values specific Gargut- and / or cooking appliance sizes are determined, and the specific specific Gargut- and / or cooking appliance sizes are used for Garprozesssteuerung. In this case, temperature difference values between sensors arranged spatially separated along the insertion direction of the cooking process sensor can be detected and used for cooking process control. The detected temperature difference values can be used in particular to achieve a set cooking result.

It is the object of the present invention to overcome the disadvantages of the prior art at least partially and in particular to provide a particularly user-friendly option for controlling a cooking cycle of the type mentioned.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims.

The object is achieved by a method for controlling a cooking cycle by determining a curve of a temperature difference of at least two temperature sensors of a core temperature sensor, wherein determining the course of the temperature difference comprises determining a maximum value of the temperature difference.

By considering the maximum value, there is the advantage that a particularly user-friendly and reliable control of the cooking cycle is made possible in a simple manner. An elaborate and often markedly faulty temporal extrapolation or iteration of temperature profiles of the temperature sensors can be dispensed with.

In other words, during operation of such a core temperature sensor in a food to be cooked, a temperature difference is formed between measured values of at least two temperature sensors. The formation of such a temperature difference takes place in particular continuously or at intervals in order to determine a time course of the temperature differences thus formed. The cooking time is then determined depending on a time course of such temperature differences.

In particular, with a core temperature sensor having more than one measuring point, an evaluation of temperature measured values should be carried out so that an optimum cooking result is achieved. The user is freed from the input of a desired core temperature or desired cooking time. It is exploited that the temperature difference between two core temperature sensors initially increases after introduction of food into a cooking chamber, since a further away from the core and thus further outward temperature sensor heats up faster than a near-core temperature sensor. Only when temperatures are approaching again or when the temperature difference is reduced does it indicate that the food in the food is sufficient even near the center of the kernel. To determine the state of the cooking, it is thus advantageous to wait until the maximum value of the temperature difference has been reached.

In the presence of three or more temperature sensors, the temperature difference may in particular correspond to a (maximum) difference between the largest temperature value and the smallest temperature value of the temperature sensors measured at a common time.

The temperature difference may be a temporal instantaneous value, a time-averaged value or a maximum value within a predetermined observation period. The maximum value has the advantage that it is particularly useful for gradual temperature values allows a reliable comparison of the temperature difference.

One embodiment is that the method comprises comparing the temperature difference with at least one predetermined threshold value after exceeding the maximum value. The threshold value may in particular correspond to a desired state of cooking. As a result, it is possible to dispense with an input of a setpoint core temperature, and the desired setpoint cooking state can be determined considerably more reliably. This also happens independently of a size or a weight and / or a shape of the food.

It is a development that an action is triggered when reaching or falling below the threshold, e.g. a cooking process is terminated and / or an audible and / or visual indication signal is output to a user. For example, may be switched from a cooking program to a keep-warm program.

An embodiment of this is that a threshold value can be selected from a group of different threshold values and the different threshold values correspond to different selectable setpoint cooking states. This allows a flexible setting of the target cooking state. For example, beef can be cooked to different levels according to the user. Consequently, e.g. a first threshold value corresponds to the set cooking state 'English', a second, lower threshold value corresponds to the set cooking state 'medium' and a third, even lower threshold value corresponds to the set cooking state 'cooked through'.

It is also an embodiment that a remaining cooking time of the cooking cycle is determined based on a period of time until reaching the maximum value. This allows a particularly simple determination of the remaining cooking time. On an elaborate extrapolation, iteration or similar can be dispensed with. In particular, the remainder of the time may be displayed to a user, particularly as support for his time management, so that he may schedule the time for a meal or timely initiation of preparation of other, less time consuming items such as side dishes or salads.

It is an embodiment of the fact that the maximum determinable remaining cooking time (or its length) corresponds to the time duration until reaching the maximum value, namely from reaching the maximum value. It is exploited that the maximum value occurs approximately at half the total duration. Thus, the remaining cooking time starts to count at the time of determining the (e.g., first or last) maximum value of the temperature difference, and is counted down therefrom.

The achievement of the maximum value or the corresponding time may, for example, be placed on the time center of the plateau or on its beginning or its end in the presence of a plateau (in which the maximum value is assumed for a predetermined period of time and / or several times). Practically best results have resulted in setting the maximum value to a time which is the last time the maximum value was reached.

However, the remaining cooking time may also be determined from another multiple of the time to reach the maximum value (e.g., 0.7 or 1.3 times the time to reach the maximum value), e.g. depending on a quantity of food or a type of food.

In particular, the food may be meat (e.g., loin, knuckle, neck, neck, etc.) or vegetables (e.g., a potato).

The object is also achieved by a household appliance, which is set up for controlling a cooking process, wherein the household appliance is adapted to carry out the control by means of the method of the preceding claims.

One embodiment is that the household appliance is a core temperature sensor, which has at least two spatially separated or spaced along its insertion direction arranged temperature sensors. The core temperature sensor may have electronics in which at least part of the method described above, in particular an evaluation, can take place. According to a development, the at least two, preferably three or more temperature sensors are arranged in the longitudinal direction of the sensor tube in the sensor tube spaced, in particular arranged equidistantly spaced. As a result, the temperature sensors are located after the insertion of the sensor tube in a food to be cooked at different depths in the food or at a different distance to the food surface. The temperature difference thus particularly reflects a difference between temperature values near a food surface and near a cooking product core.

Another embodiment is that the device is communicatively coupled to the core temperature sensor cooking appliance. The object is thus achieved according to a development also by such a cooking appliance. The coupling can be wireless or wired.

The cooking appliance is therefore in particular configured to run the process on the basis of temperature values received from the core temperature sensor. The Cooking appliance has in particular an evaluation circuit or electronics. The evaluation circuit may be a central control device of the cooking appliance.

According to a development, the method can also be distributed with regard to individual method steps to an electronic unit in the core temperature sensor and an electronic unit in the cooking appliance.

It is still an embodiment that the cooking appliance is adapted to perform at least one action after reaching or falling below the predetermined threshold and / or after reaching the remaining time. The action may include, for example, outputting an optical and / or acoustic alert signal to a user. The action may additionally or alternatively include turning off or switching a program, mode or function, e.g. switching off a cooking mode.

The cooking appliance may for example be an oven or a stove, but also a microwave oven, a steamer or a combination thereof.

In the following figures, the invention will be described schematically with reference to an embodiment schematically. In this case, the same or equivalent elements may be provided with the same reference numerals for clarity.

1 shows a multipoint core temperature sensor with temperature sensors in a cooking appliance;

2 shows, as a plot of a temperature measured values of the temperature sensors over the time of a usual Garablaufs;

3 shows a time course of the temperature difference and a threshold for determining a cooking time end; and

4 shows the time course of the temperature difference 2 and a method for determining a remaining time for cooking.

1 shows a multipoint core temperature probe 11 , The core temperature probe 11 is designed to measure a core temperature of food to be cooked G (eg a piece of meat or a potato), which is in a cooking chamber 13 a cooking appliance 12 for heat treatment is located. In the cooking appliance 12 it is for example an oven and the cooking chamber 13 around a stove room.

The core temperature probe 11 has a handle 14 on. From the handle protrudes a sensor tube 15 , which is also known as a spit. The sensor tube 15 is formed substantially as a hollow tube and is closed at its free end for piercing the food to be cooked G and tapered. In the sensor tube 15 are exemplary three temperature sensors 16 . 17 . 18 along its longitudinal direction between the tip and the handle 14 arranged. By means of temperature sensors 16 . 17 . 18 corresponding temperatures T1, T2 and T3 are sensed or measured, for example in steps of 1 K.

A first of the temperature sensors 16 is preferably arranged near the top. Dashed electrical lines lead from the temperature sensors 16 . 17 . 18 in the grip 14 and via a connection cable 22 on to a control device 21 of the cooking appliance 12 , The control device 21 is among other things set up, the functions of the cooking appliance 12 to control.

The control device 21 is further adapted to continuously determine a maximum TMAX (T1, T2, T3) and a minimum TMIN (T1, T2, T3) of the n (here: n = 3) measured temperatures T1 to T3 and from this a (largest) temperature difference D = TMAX - TMIN. The determination of the temperatures T1 to T3 happens, for example, every minute. The control device 21 may additionally or alternatively determine corresponding temperature profiles, in particular the course of the temperature difference D = D (t) over the time t.

Investigations have shown that certain foods have a typical behavior of temperatures T1, T2, T3 or temperature difference D = D (t), as in 2 exemplary of a piece of meat, especially pork neck, shown. Shown is the time course of the temperatures T1, T2, T3 of the three temperature sensors 16 . 17 . 18 by way of example in degrees Celsius over time t in minutes.

In a first region B1 extending from 0 to about 10 minutes of the total duration, all three temperatures T1, T2, T3 are approximately equal, although two of the temperature sensors 16 and 17 rather close to the core or are plugged as a rather outside of the food G arranged temperature sensor 18 ,

A second area B2 extends from about 10 to 60 minutes. There, in particular, the greatest temperature difference D (t) of the measured temperatures T1 = TMAX and T3 = TMIN increases between the warmest measuring point or temperature sensor 18 and the coldest measuring point or temperature sensor, eg 16, first (up to approx. t = 25 min) and then at least approximately the same. The measured temperature T2 of the temperature sensor 17 between the two other temperatures T1 and T3 is relatively close to the temperature T3 of the coldest temperature sensor 16 ,

A third area B3 extends from about 60 to 110 minutes. In this region B3, the temperature difference, in particular D (t) = TMAX - TMIN, of the measured temperatures T1 to T3 between the temperature sensors decreases 16 to 18 again. When an ideal cooking time is reached at approx. T = 120 (not shown), the temperature difference D (t) of the temperatures T1 to T3 is virtually zero. At this time, a core temperature of, for example, 85 ° C is reached.

3 shows a so determined or calculated time course of the temperature difference D (t) for pork neck. The temperature difference D (t) first increases until about t = 25 min and then, taking into account usual fluctuations, reaches a plateau between t = 25 min and t = 60 min, in which the temperature difference D (t) in a period of observation (time window ) reaches its maximum value DMAX = 8 K or 8 ° C at least once from about five to ten minutes.

From about t = 60 min, the temperature difference D (t) decreases again. The last time TDMAX, at which the maximum temperature difference DMAX = 8 K has been reached, now serves as a reference for two determinations, namely firstly for a determination of a desired cooking state and secondly for a determination of a remaining time TREST of the cooking process until complete cooking.

Upon determining TDMAX and thus recognizing that the maximum DMAX of the temperature difference D (t) has been exceeded, a method for determining a desired cooking state is enabled. For this purpose, a threshold value DG is used (here: DG = 1 K), which corresponds to a desired cooking state desired by a user. This threshold value DG = 1 corresponds to a temperature difference D (t) = 1 and therefore to a good, but not completely cooked food G. Other selectable threshold values can be eg DG = 3 for 'medium' or DG = 5 for 'English' and of one User or a cooking program of the cooking appliance 12 be specified. Upon reaching the threshold (at least for a predetermined period of observation) the cooking appliance switches 12 its cooking mode (cooking time end TE) and outputs eg a warning signal.

The determination of a remaining cooking time TREST from the end TDMAX of the plateau of the maximum DMAX of the temperature difference D (t) (ie, the last time DMAX was detected) is set equal to TDMAX, that is TE = 2 × TDMAX. The remaining time TREST can a user as a maximum useful time to compare the food G in the oven 13 are displayed.

The method works especially with certain types of meat, e.g. Loin, Haxe. Neck, neck, and in certain vegetables, e.g. Potatoes.

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

In particular, only two or more than three temperature sensors may be used in the sensor tube instead of the three temperature sensors. The temperature difference D preferably remains the difference value of the highest and lowest two temperatures measured at a time.

Evaluation and control functions can be implemented entirely in the control device of the cooking appliance. However, alternatively, at least parts of the evaluation and control functions can be implemented in an electronics of the temperature sensor.

Evaluation and control functions can in particular be used in combination with an automatic program of the cooking appliance.

LIST OF REFERENCE NUMBERS

11

 Core probe

12

 Cooking appliance

13

 oven

14

 Handle

15

 sensor tube

16

 temperature sensor

17

 temperature sensor

18

 temperature sensor

21

 control device

22

 connection cable

B1

 first temperature range

B2

 second temperature range

B3

 third temperature range

D

 temperature difference

DG

 threshold

DMAX

 Maximum of D

G

 be cooked

t

 Time

T

 temperature

T1

 instantaneous temperature of the first temperature sensor

T2

 instantaneous temperature of the second temperature sensor

T3

 instantaneous temperature of the third temperature sensor

TDmax

 Time of DMAX

TE

 end of cooking time

TREST

 remaining cooking

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 29923215 U1 [0004]

Claims (9)

Method for controlling a cooking cycle by determining a course of a temperature difference (D) of at least two temperature sensors ( 16 . 17 . 18 ) of a core temperature probe ( 11 ), characterized in that determining the course of the temperature difference (D) comprises determining a maximum value (DMAX) of the temperature difference (D). A method according to claim 1, characterized in that the method comprises comparing the temperature difference (D) with a predetermined threshold value (DG) after exceeding the maximum value (DMAX), wherein the threshold value (DG) corresponds to a desired state of cooking. Method according to Claim 2, characterized in that the predetermined threshold value (DG) can be selected from a group of different threshold values (DG = 1, DG = 3, DG = 5) and the different threshold values (DG) correspond to different target cooking states. Method according to one of the preceding claims, characterized in that a remaining cooking time (TREST) of the cooking cycle is determined on the basis of a time duration until the maximum value (DMAX) is reached. A method according to claim 4, characterized in that the maximum determinable residual duration (TREST) of the time duration until reaching the maximum value (TDMAX) corresponds, and continuously from reaching the maximum value (DMAX). Household appliance ( 11 . 12 ), which is set up to control a cooking process, characterized in that the domestic appliance ( 11 . 12 ) is arranged to perform the control by the method of the preceding claims. Domestic appliance according to claim 6, characterized in that the household appliance a core temperature sensor ( 11 ), which has at least two temperature sensors arranged spatially separated along its insertion direction ( 16 - 18 ) having. Household appliance ( 12 ) according to one of claims 6 or 7, characterized in that the household appliance with the core temperature sensor ( 11 ) communicatively connectable cooking appliance ( 12 ). Apparatus according to claim 8, characterized in that the cooking appliance ( 12 ) is arranged to perform at least one action after reaching or falling below the predetermined threshold (DG) and / or after reaching the remaining time (TREST).

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