EP0609762A1 - Cooking apparatus having browning- and microwave generating devices and method for controlling the cooking in such an apparatus - Google Patents

Abstract

The invention relates to a cooking apparatus (1) which includes a browning device (3), a device (4) for generating microwave energy, means for selecting heating sequences and means for controlling the electrical power supply circuit of the browning device and/or of the device for generating microwave energy. When one heating sequence is initiated, after a user has selected the type and the weight of a foodstuff to be treated, the control means of the cooking apparatus determine an optimum heating time T which depends, on the one hand, on a threshold weight value P0 and, on the other hand, on the selected heating sequence. <IMAGE>

Description

The present invention relates to a cooking appliance comprising a cooking cavity comprising a device for browning food with electrical resistance placed inside said cavity and a device for generating microwave energy placed outside of the cavity and capable of supplying said cavity with microwave energy, a supply circuit for supplying the browning device and / or the microwave energy generation device, selection means making it possible to trigger a sequence of heating, said heating sequence involving the browning device and / or the microwave energy generation device, entering the nature and the weight of the food, and control means which activate the supply circuit electrical as a function of the information from the selection means, said control means comprising a storage memory receiving the information from the mo selection yen and a microprocessor supplying signals applied to the supply circuit according to the information contained in said storage memory.

In known cooking appliances of this kind, when a food is placed inside the cooking cavity, a user begins a heating sequence by selecting a determined heating function, a family of foods and its weight. and, then by pressing a button, it initiates said heating sequence. The control means determine the heating sequence (browning device and / or microwave energy generation device) thus calculating the heating time of the cooking appliance so that the food undergoes the best possible treatment.

However, a food family generally includes several types of food. The VOLAILLES family includes, for example, chickens, ducks, guinea fowl, quail, pheasants ... The control means, after analysis of the selected family, determines a heating sequence which is adapted to the average population of the family. foods and not to each type of food. Furthermore, for foods of low weight and whose heating sequence involves at least the browning device, the heating sequence calculated by the control means makes it possible to obtain either a food that is too golden but not cooked enough, or a food overcooked but not browned enough. The calculated heating sequence therefore never exactly meets the wishes of the user, namely obtaining a sufficiently cooked and golden food whatever the type and weight of the food to be treated.

The object of the invention is to remedy the aforementioned drawbacks by using a cooking appliance which, taking into account the type and weight of the food to be treated, determines the optimal heating sequence selected by the user to obtain a sufficiently cooked and golden food.

• des valeurs i correspondant à des séquences de chauffage ;
• des numéros de codes α_i correspondant chacun à un type d'aliment particulier pour une valeur i déterminée, et délimités, pour chaque valeur i, entre une valeur inférieure m_i et une valeur supérieure M_i ;
• des tableaux de valeurs correspondant à des coefficients de pentes km_i et kM_i de courbes d'optimisation de chauffage d'un aliment qui sont prédéterminées en fonction des valeurs i, et qui représentent le temps de chauffage de l'appareil de cuisson en fonction du poids de l'aliment, lesdits coefficients correspondant respectivement à des valeurs de pentes minimum et maximum desdites courbes.

According to a first characteristic of the invention, the storage memory contains:

• i values corresponding to heating sequences;
• code numbers α _i each corresponding to a particular type of food for a determined value i, and delimited, for each value i, between a lower value m _i and a higher value M _i ;
• tables of values corresponding to slope coefficients km _i and kM _i of optimization curves for heating a food which are predetermined in as a function of the values i, and which represent the heating time of the cooking appliance as a function of the weight of the food, said coefficients corresponding respectively to minimum and maximum slope values of said curves.

According to another advantageous characteristic of the invention, the storage memory contains a table of values of coefficients a _i for each value i and a threshold value P₀ corresponding to a determined value of abscissa of the optimization curves below which , for a heating sequence involving at least the browning device, the control means calculating the heating time take into account a weighting coefficient whose value is determined by the product of the coefficient a _i by the value P₀.

Thanks to the heating appliance according to the invention, the plurality of selectable codes favor the refinement of the heating optimization curves, thus making it possible to calculate, with greater precision, the heating time of the cooking appliance. On the other hand, for heating sequences involving the browning device, it is essential to take into account the weight of the food. This is why, with the control of the weight of the food relative to a determined threshold weight, one acts on the heating time of the cooking appliance which, if the weight of the food is less than the weight of threshold P₀, varies non-linearly according to the weight of the food, and, if the weight of the food is greater than the weight of threshold P₀, varies linearly depending on the weight of the food.

• la figure 1 est une vue en plan en coupe d'un appareil de cuisson selon l'invention,
• la figure 2 est une représentation graphique de courbes d'optimisation de chauffage qui montrent, compte tenu d'une séquence de chauffage déterminée, le temps de chauffage de l'appareil de cuisson en fonction du poids de l'aliment sélectionné,
• la figure 3 est un schéma fonctionnel représentant le procédé de commande de cuisson de l'appareil de cuisson selon l'invention.

The characteristics and advantages of the invention will become apparent from the description which follows, taken by way of nonlimiting example, with reference to the drawings in which:

• FIG. 1 is a plan view in section of a cooking appliance according to the invention,
• FIG. 2 is a graphical representation of heating optimization curves which show, taking into account a determined heating sequence, the heating time of the cooking appliance as a function of the weight of the selected food,
• Figure 3 is a block diagram showing the cooking control method of the cooking appliance according to the invention.

According to FIG. 1, a cooking appliance 1 such as an oven comprises a cooking cavity 2 comprising a browning device 3 placed inside the cooking cavity 2 and a microwave energy generation device 4 placed outside the cooking cavity 2. An electrical supply circuit not shown and capable of supplying the browning device 3 and / or the microwave energy generation device 4. The cooking cavity 2 is delimited by a door 5 shown in dotted lines and placed on the front face 6 of the cooking appliance. This partially shown front face 6 includes selection means not shown which make it possible to trigger a heating sequence to be carried out on a food 7, to capture the nature 7 as well as the weight of the food 7.

The cooking appliance 1 comprises control means, not shown, which comprise, on the one hand, a storage memory receiving information from the selection means and, on the other hand, a microprocessor supplying signals applied to the circuit according to the information contained in the storage memory.

, où K représente la pente de la courbe.According to FIG. 2, an optimization curve 8 of a heating sequence of a food involving only the microwave energy generation device represents the heating time T defined for example as ordered as a function of the weight P food defined for example as abscissa. Such a curve is generally linear in shape and is defined by the relation $\text{T = KP}$

, where K represents the slope of the curve.

For a heating sequence involving at least the browning device, experiments on food placed in a cooking appliance have made it possible to define, as a function of the nature and weight of the food, an optimization curve 9 of said sequence of heating. This curve 9 shows that, for light weight food, browning by the grill is not proportional to the heating time. During a heating sequence involving the browning device and the microwave energy generation device, and for foods whose weight is P₁, the foods are either well roasted but overcooked, point A of the curve 9; well cooked but not roasted enough, point B of curve 8.

• des valeurs i correspondant à des séquences de chauffage,
• des numéros de codes α_i correspondant chacun à un type d'aliment particulier pour une séquence de chauffage déterminée et délimités, pour chaque séquence de chauffage, entre une valeur inférieure m_i et une valeur supérieure M_i,
• des tableaux de valeurs correspondant à des coefficients de pentes km_i et kM_i de courbes d'optimisation de chauffage d'un aliment, prédéterminées en fonction de la valeur i, représentant le temps de chauffage de l'appareil de cuisson, défini comme ordonnée, en fonction du poids de l'aliment, défini comme abscisse, lesdits coefficients correspondant respectivement à des valeurs de pentes minimum et maximum desdites courbes.

To take account of the type of food to be processed, the storage memory of the control means contains:

• i values corresponding to heating sequences,
• code numbers α _i each corresponding to a particular type of food for a determined heating sequence and delimited, for each heating sequence, between a lower value m _i and a higher value M _i ,
• tables of values corresponding to slope coefficients km _i and kM _i of optimization curves for heating a food, predetermined as a function of the value i, representing the heating time of the cooking appliance, defined as ordinate, as a function of the weight of the food, defined as the abscissa, said coefficients corresponding respectively to minimum and maximum slope values of said curves.

Thanks to said information contained in the storage memory, the control means comprising first calculation means determine a slope value K _i of the optimization curve of the heating sequence to be calculated by the relation:

On the other hand, to take account of the effect produced by the gilding device, the storage memory contains a table of values of coefficients a _i for each value i and a threshold value P₀ corresponding to a determined value of abscissa of the optimization curves below which, for a heating sequence involving at least the browning device, the control means calculating the heating time take into account a weighting coefficient whose value is determined by the product of the coefficient a _i by the value P₀. As illustrated by curve 9 in FIG. 2, the abscissa P₀ corresponds to the inflection point of the optimization curves for cooking of different types of food, the section of curve of coordinate less than P₀ corresponding to a heating sequence with at least the gilding device.

The weight threshold P₀ is substantially equal to 400 g. Said control means thus comprise second calculation means for, on the one hand, comparing the weight of the selected food with the weight threshold P₀ and, on the other hand, determine, as a function of the result of the comparison of the weights, the heating time of the cooking appliance.

If the weight of the selected food is less than or equal to the weight threshold P₀, the heating time T is defined by the relation:

${\text{T = (K}}_{\text{i}}{\text{- at}}_{\text{i}}{\text{) P + a}}_{\text{i}}\text{P₀}$

If the weight of the food is greater than or equal to the weight threshold P₀, the heating time T is defined by the relation:

${\text{T = K}}_{\text{i}}\text{P}$

To prevent the calculated heating times from being harmful to the proper functioning of said cooking appliance, the storage memory contains, for each heating sequence, a maximum heating time not to be exceeded and the control means include third means of calculation which, on the one hand, compares the heating time calculated by the second calculation means with the maximum heating time for a determined heating sequence and, on the other hand, as a function of the result from the third calculation means, trigger either an error message if the calculated time is greater than the maximum time, or the heating sequence determined by the control means.

In order to illustrate the operation of the oven, there is shown in Figure 3 a flowchart corresponding to the method of controlling the cooking of a food.

During a first operation, after the user has placed a food to be treated in the cooking cavity, the user selects a heating sequence, the weight of the food and a code number α _i corresponding to the particular food to be treated. Then he presses a start button to start the operation of the cooking appliance. During a second operation, the information entered by the user is transmitted to the control means which, taking into account the information stored in the storage memory, determine the slope value K _i of the sequence optimization curve selected heating system.

Then, during a third operation, the control means carry out a test on the weight of the food to be treated with respect to the weight threshold P₀. In a first case, if the selected heating sequence involves at least the browning device and if the weight of the food to be treated is less than the weight threshold P₀, the control means determine the heating time T by the relation :

${\text{T = (K}}_{\text{i}}{\text{- at}}_{\text{i}}{\text{) P + a}}_{\text{i}}\text{P₀}$

In a second case, if the selected heating sequence involves the browning device and / or the microwave energy generation device and if the weight of the food to be treated is greater than the weight threshold P₀, the means controls determine the heating time T by the relation:

${\text{T = K}}_{\text{i}}\text{P}$

In each of the two cases, the control means first compare the calculated heating time corresponding to an optimal heating time value with the maximum heating time contained in the storage memory and then trigger or not the activation of the circuit. powering the browning device and / or the microwave energy generation device.

Thus, the method according to the invention offers the advantage of obtaining an automatic cooking of the food thanks to the precision concerning the nature of the food. In addition, taking into account the selected heating sequence and the weight of the food, the optimization curve is refined by approaching an ideal optimization curve, said curve obtained making it possible to meet the expectations of each user.

Claims (10)

Cooking appliance (1) comprising a cooking cavity (2) comprising a device for browning (3) of electric resistance food placed inside said cavity (2) and a device for generating microwave energy ( 4) placed outside the cooking cavity (2) and capable of supplying said cavity with microwave energy, an electrical supply circuit for supplying the browning device (3) and / or the generation device of microwave energy (4), selection means making it possible to trigger a heating sequence to be carried out on a food, said sequence involving the browning device and / or the microwave energy generation device, enter the nature and the weight of the food and of the control means which activate the electrical supply circuit as a function of the information coming from the selection means, said control means comprising a storage memory receiving the inf orations from the selection means, and a microprocessor supplying signals applied to the power supply circuit as a function of the information contained in the storage memory,
characterized in that the storage memory contains: - i values corresponding to heating sequences; - code numbers α _i each corresponding to a particular type of food for a determined value i, and delimited, for each value i, between a lower value m _i and a higher value M _i ; - tables of values corresponding to slope coefficients km _i and kM _i of heating optimization curves for a food which are predetermined as a function of the values i, and which represent the heating time of the cooking appliance in depending on the weight of the food, said coefficients corresponding respectively to minimum and maximum slope values said curves. Cooking appliance according to claim 1,
characterized in that the storage memory contains a table of values of coefficients a _i for each value i and a threshold value P₀ corresponding to a determined value of abscissa of the optimization curves below which, for a heating sequence involving at least the gilding device, the control means calculating the heating time take into consideration a weighting coefficient whose value is determined by the product of the coefficient a _i by the value P₀. Cooking appliance according to claim 2,
characterized in that the heating optimization curves of a food representing on the abscissa the weight of the food and on the ordinate the heating time correspond beyond the abscissa value P₀ to linear functions, and below of said value P₀, for a heating sequence involving at least the gilding device, correspond to sampled functions of ordinate at the origin different from those of said linear functions. Cooking appliance according to claim 2 or 3,
characterized in that the control means comprise first calculation means which use the value i, the code numbers α _i , the values m _i and M _i and the slope values km _i and kM _i to determine a slope value optimum K _i of the heating optimization curve of the selected sequence. Cooking appliance according to any one of the preceding claims,
characterized in that the slope value K _i is determined by relation:

Cooking appliance according to claim 2,
characterized in that the control means comprise second calculation means for, on the one hand, comparing the weight of the selected food with the weight threshold P₀ and, on the other hand, determining, as a function of the result of the comparison of the weights, the heating time of the cooking appliance. Cooking appliance according to claim 6,
characterized in that , on the one hand, the weight of the food being less than or equal to the weight threshold P₀, the control means calculate the heating time T which is defined by the relation:
${\text{T = (K}}_{\text{i}}{\text{- at}}_{\text{i}}{\text{) P + a}}_{\text{i}}\text{P₀}$

and on the other hand, the weight of the food being greater than the weight threshold P₀, the control means calculate the heating time T which is defined by the relation:
${\text{T = K}}_{\text{i}}\text{P}$

Cooking appliance according to any one of Claims 2 to 7,
characterized in that the weight threshold P₀ is substantially equal to 400 g. Cooking appliance according to claim 6,
characterized in that the storage memory contains, for each heating sequence, a maximum heating time not to be exceeded, and in that the control means comprise third calculation means which, on the one hand, compare the time heating calculated by the second calculation means with the maximum heating time for a determined heating sequence and, on the other hand, depending on the result from said third calculation means, trigger either an error message if the calculated time is greater than the maximum time, or a heating sequence determined by the control means. Cooking control method for a cooking appliance according to any one of Claims 2 to 9,
characterized in that it comprises a first operation in which, on the one hand, a heating sequence is selected, the weight of the food and a code number α _i , and, on the other hand, the start is started of the cooking appliance, a second operation in which the control means calculate an optimum slope value K _i of the optimization curve of the heating sequence selected as a function of the code α _i , of the values m _i and M _i and values km _i and kM _i , and a third operation in which the control means compare the weight of the selected food with a threshold value P₀ contained in the storage memory and determine, as a function of the weight of the food, an optimal value for the heating time of the cooking appliance.

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