The present invention relates to a cooking oven, in particular a domestic electrical oven.
Domestic cooking ovens usually comprise a housing with a cooking cavity which delimits inside a cooking space for accommodating the food to be cooked. The cooking cavity has an access opening which can be closed by means of a door hinged to the housing.
In order to heat the cooking space, the cooking cavity is provided, at its lower and upper walls, with heating elements typically formed by electrical resistors.
In order to obtain a preferably uniform distribution of the heat in the cooking space, the electrical cooking ovens comprise an air circulation system in the cooking cavity. Typically, such an air circulation system comprises an impeller operated by an electrical motor in flow communication with the cooking cavity so as to be able to generate an air circulation in the cooking space.
In order to avoid the overheating of electrical or electronic components of the oven as well as burns to the user during use of the cooking oven, it is known to cool such thermally sensitive components and/or a grip zone of the door by means of a cooling air stream.
For such purpose, the ovens of the prior art may comprise a fan placed in a cooling compartment arranged over the cooking cavity and which can be operated to suck ambient air, e.g. through an intake opening formed in a rear wall of the housing, and to direct it towards the thermally sensitive components and/or through a horizontal slot of the front wall of the oven in the anterior front zone (grip zone) of the oven door.
Traditionally, the cooling of the thermally sensitive components of the oven is activated when the oven is switched on and remains on for the entire operating time of the oven until it is switched off. This ensures fully safe operation of the oven and avoids undesired overheating at the cost of a permanent consumption of electrical energy.
The ventilating of the cooking space may be turned on or off by the user as a function of the cooking recipe. Once on, the ventilating of the cooking space remains permanently on until it is switched off manually regardless of the operation of the heating resistors of the oven. Thereby, the ventilating of the cooking space also implies a permanent consumption of electrical energy.
More recently, intermittent cooling systems have been suggested provided with a sophisticated control to optimize the cooling of thermally sensitive components or cooking parameters of particular food.
Compared with the traditional ovens, the more sophisticated ventilating control systems also comply with the energy saving needs but require more complex electronic or electrical controllers which, in turn, are costly and subjected to fault and malfunctioning. Furthermore, even renouncing permanent ventilating of the oven the residual risk of overheating cannot be excluded.
It is the object of the present invention to suggest a cooking oven, in particular of the domestic electrical type having features to better conciliate the needs of:
In other words, the control system automatically switches on the fan together with switching on the heating means and automatically switches the fan off together with switching off the heating means so that the fan is actuated intermittently in a synchronized manner with the actuation of the heating means.
Thereby, each step of heating of the cooking cavity is automatically and permanently accompanied by the ventilation of the thermally sensitive region of the oven (e.g. cooking cavity and/or thermally sensitive components, door) thus effectively avoiding the risk of overheating. Furthermore, during all periods in which the heating of the cooking cavity is deactivated and there can be no further increase of the thermal energy accumulated therein, the ventilation of the thermally sensitive region to which the fan is associated is deactivated and the respective consumption of electrical energy is canceled out.
Finally, the joint switching of the heating means and of the electrical fan makes the control system simpler and more robust because both functions can be managed with the same electrical control circuit.
In order to better understand the invention and appreciate its advantages, some non-limitative embodiments will be described below with reference to the figures, in which:
With reference to the figures, a cooking oven 1 comprises a housing 2, in which a cooking cavity 3 is formed intended to accommodate the food to be cooked. The cooking cavity 3 has an access opening 4 which can be closed by means of a door 5 hinged to the housing 2.
The oven 1 further comprises a heating system of the cooking cavity 3, e.g. one or more electrical resistors 6, 6' arranged outside and/or inside the cooking cavity 3.
A ventilating system with one or more recirculation and/or ventilating and/or cooling impellers 7, 7', which can be operated by electrical motors 8, 8' mixes the air inside the cooking cavity 3 to suck and exhaust cooking fumes and/or for cooling thermally sensitive components of the oven 1, such as for example the door 5 and/or the electrical or electronic components 9.
The oven 1 further comprises a control system 10 connected and configured to control the heating means 6, 6' and the ventilating means 7, 7' and having a user interface 11 for selecting operating parameters and for indicating operating conditions of the oven 1.
According to the invention, the control system 10 comprises a temperature detector 12 associated with the cooking cavity 3 and is configured to activate and deactivate the heating means 6, 6' according to a temperature detected by the temperature detector 12 and a desired temperature selected by means of the user interface 11.
The ventilating means comprise a first electrical fan 7', 8' positioned in a cooling compartment 13 formed, for example, over the cooking cavity 3 which can be operated to suck ambient air through an intake opening 14 in a wall of the housing 2, and to direct it as a first stream 14 (cooling stream) towards the heat sensitive components 9 placed inside the housing 2 and/or in a grip region 15 of the door 5 of the oven 1.
According to the invention, the control system 10 automatically activates and deactivates the first electrical fans 7', 8' together with activating and deactivating the heating means 6, 6', regardless of the settings and/or cooking program selections made by the user.
The ventilating means may comprise a second electrical fan 7, 8 in flow communication with the cooking cavity 3 so as to be able to generate a second air stream 16 (heat distribution stream) in the cooking cavity 3.
According to the invention, the control system 10 allows the selection of a cooking program with air circulation in the cooking cavity 3, and when the cooking program with air circulation in the cooking cavity 3 is selected, the control system 10 automatically activates and deactivates the second electrical fan 7, 8 together with activating and deactivating the heating means 6, 6'.
The control system 10 may also allow the selection of a cooking program without air circulation in the cooking cavity 3, and, when the cooking program without air circulation in the cooking cavity 3 is selected, the control system 10 keeps the second electrical fan 7, 8 automatically deactivated, regardless of the operation of the heating means 6, 6'.
In an embodiment, the heating means 6, 6', 6" can comprise one or more lower heating elements 6 arranged at a lower wall of the cooking cavity 3, one or more upper heating elements 6' arranged at an upper wall of the cooking cavity 3, as well as optionally one or more rear heating elements 6" arranged at the rear wall of the cooking cavity 3,
and the control system 10 is configured to allow the selection of programs or cooking modes and to set the cooking mode as a function of the cooking programs selected by the user, said cooking modes comprising one or more of the following:
In mode A) the control system 10 operates the second electrical fan 7, 8 in:
In mode B) with ventilating of the cooking cavity 3, the control system 10 operates the second electrical fan 7, 8 in:
In mode C) with ventilating of the cooking cavity 3, the control system 10 operates the second electrical fan 7, 8 in:
In mode D) with ventilating of the cooking cavity 3, the control system 10 operates the second electrical fan 7, 8 in:
With reference to the aforesaid operating modes A), B), C), D), one criterion for choosing energy saving mode or standard mode is the necessary and/or predicted/estimated electrical power absorption to execute the cooking program or the cooking mode selected by the user.
In an advantageous embodiment, in energy saving mode, the control system 10 automatically activates and deactivates the first 7', 8' and second 7, 8 electrical fans together with activating and deactivating the heating means.
The oven according to the invention has many advantages. Each step of heating of the cooking cavity 3 is automatically and permanently accompanied by the ventilating of the thermally sensitive region of the oven 1, thus effectively avoiding the risk of overheating. Furthermore, during all periods in which the heating of the cooking cavity 3 is deactivated and there can be no further increase of the thermal energy accumulated therein, the ventilation of the thermally sensitive region is deactivated and the respective consumption of electrical energy is canceled out.
Finally, the joint switching of the heating means and of the ventilating means of the oven 1 makes the control system simpler and more robust because both functions can be managed with the same electrical control circuit.
Obviously, those skilled in art may make further changes and variants to the heating oven according to the present invention all without departing from the scope of protection of the invention, as defined in the claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.