Patent Application
20230213200
The present invention concerns to a food cooking unit equipped with one or multiple gas burners controlled through one or more regulating electrovalves, at least one thermocouple to detect accidental shutdown of the gas burners, at least one food monitoring sensor for each cooking zone configured to monitor a cooking process carried out on the cooking zone and/or a weight sensor for each cooking zone configured to detect weight variations on the cooking zone, and an electronic control device, connected to said at least one food monitoring sensor and/or weight sensor, to the at least one thermocouple and to the regulation electrovalves, allowing automatic regulation of the heat source following a program stored in the electronic control device, in response to readings from the food monitoring sensor, from the weight sensor and/or from the at least one thermocouple.
The electronic control device used in this invention can integrate a programmable device such as a PLC and will generally comprise a control unit that integrates a microcontroller or the like with memories, that provides an electronic control unit and that operates in functions of control from signal inputs from various detectors/sensors, in safety and management functions, through storage, for example of recipes and monitoring of cooking programs.
Consequently, in this memory, an electronic control device or control unit will be used interchangeably to refer to the same device.
Cooking units equipped with an infrared sensor and an electronic control device which allows regulating several gas burners that define a cooking zone based on the readings of the infrared sensor, are known.
For example, the document DE4422354 is known, and it describes a cooking unit equipped with an infrared sensor located above the cooking zone, oriented to read the temperature of the side wall of a cookware arranged in the cooking zone. This solution only allows knowing the temperature of a peripheral region of a cookware, but not the temperature of the food contained within said cookware. Therefore if, for example, the cookware was off-centre heating one side more than the other, the infrared sensor would give erroneous readings and therefore would not allow a correct regulation of the heat source.
The document CN104266233 also describes a similar device, but in which the infrared sensor is arranged at a higher height, oriented to capture the temperature inside a cookware arranged above the cooking zone. In this case, better regulation is achieved from the heat source, but as the infrared sensor is higher than the cooking zone, there is a risk that said infrared sensor could be damaged by high temperatures, for example, by cooking with flambé, by accidental contact of a hot cookware with said infrared sensor, by the release of vapours or by splashing oils or other liquids at high temperatures from the surface of the food under cooking. Any of these circumstances could damage the sensor or its housing or protector, especially if the sensor is located vertically or on the vertical periphery of the cooking zone
The risk of damaging the infrared sensor could be reduced by moving the infrared sensor away from the heat source, but then it becomes difficult for the infrared sensor and the other components of the cooking unit to form a compact or transportable unit.
A cooking unit equipped with annular and concentric gas burners that define a cooking zone controlled by an infrared sensor is also known in the market, the gas burners being connected to electrovalves controlled by an electronic control device.
However, in the known background, there is a common problem related to the safety shutdown of the gas flow that feeds the gas burners in the event of accidental shutdown thereof.
Usually a thermocouple is used next to a gas ignition flame, connected to a safety electrovalve that determines the closure of the gas supply when the thermocouple cools due to the flame extinguishing, thus preventing uncontrolled gas escape. However, the power of the electrical signal generated by said thermocouple is extremely low, on the order of 0.25 A and 5mV, and said electrical signal suffers significant losses due to resistance of the components during their transportation and connection with the safety electrovalve. Therefore, the electrical signal that reaches the safety electrovalve is extremely weak and any additional element or connection included in the circuit between the thermocouple and the safety electrovalve, such a connection to the electronic control device, produces an additional signal loss on the signal produced by the thermocouple which could lead to false positives that close the gas passage unduly, interrupting the cooking of food.
If the electronic control device is not connected to the electric circuit between the thermocouple and the safety electrovalve, to prevent an additional signal loss, then the control device has no information on the state of said safety electrovalve or the gas burner flame, so it does not know when cooking has been interrupted by a shutdown of the safety electrovalve caused by an interruption of the thermocouple signal.
The document EP2703723 describes a cooking unit equipped with a plurality of gas burners, each integrating a thermocouple. The thermocouples are connected to an electronic control unit, and this determines the closing of the safety electrovalve in case an accidental shutdown of the gas burners is detected through the signal generated by the thermocouples. In this solution, the safety electrovalve is governed by the control unit, and not by the thermocouple, which is why said control unit is part of the cooking unit’s safety systems and therefore must be certified and comply high reliability requirements that make it more expensive.
There is no known solution that prevents the accidental shutdown of the cooking unit and at the same time allows a complete voluntary closing of the cooking unit, guaranteeing that gas leaks do not occur due to an accidental shutdown of the flame, without the need for a complex and expensive electronic control unit certified as security equipment.
In the known products, in addition, for the regulation of the gas flow supplied to the gas burners, fixed-pitch electrovalves are commonly used. Typically, for example, two fixed-pitch electrovalves (maximum and minimum) are provided that allow supplying a different gas flow to the same burner, so that using one electrovalve, the other, or a combination of both, different flow regulations are achieved. Although fixed-pitch electrovalves are cheaper than variable-pitch electrovalves, a greater number of electrovalves are required to achieve precise control of the cooking unit, in addition to requiring complex pipes that allow connecting two electrovalves to the same gas burner. All this ends up increasing the price and increasing the size of the cooking unit.
It is therefore necessary to improve the mentioned cooking units to avoid the aforementioned problems.
The present invention concerns to a food cooking unit comprising:
It will be understood that the cooking zone is a zone where the flames of the gas burners apply heat, said zone being intended for the placement of a cookware thereon to cook food inside. The cooking zone may also be defined by cookware supports located above the at least one gas burner and intended to support a cookware.
The food monitoring sensor is a sensor intended for monitoring the cooking process of a food contained in a cookware located on the cooking zone, for example monitoring the food temperature and/or the food color. Other factors can be also examined such water content. can be, for example, a remote sensor such an infrared sensor or a camera, located above the cooking zone, preferably on one side of it, and focused downwards towards said cooking zone, to monitor the cooking process of a food contained in a cookware located on the cooking zone. Alternatively, the food monitoring sensor can be a contact sensor, such a probe or a temperature probe, to be inserted in a food contained in a cookware located on the cooking zone for monitoring its cooking process.
The at least one thermocouple is in contact with the flames produced when the gas is burned in the gas burners and/or in the ignition source. When the thermocouple is heated it produces an electric signal, but when the flame is extinguished the thermocouple colds down and the signal is interrupted.
The at least one thermocouple is directly connected to the safety electrovalve so that the signal generated by the thermocouple is transmitted directly to the safety electrovalve without interruptions.
The at least one thermocouple is also connected to the electronic control device so that the control device detects the signal transmitted by said at least one thermocouple detecting if the flames are ignited. This allows the electronic control device to interrupt the regulation program, closing the at least one regulating electrovalve and the ignition source electrovalve in response to an interruption of the signal generated by the at least one thermocouple, avoiding feeding gas when the flames able to ignite such gas are extinguished.
Preferably, the at least one thermocouple comprises at least one first thermocouple connected to the safety electrovalve, and at least one second thermocouple connected to the electronic control device.
According to that, the first thermocouple controls the safety electrovalve without intervention of the electronic control unit producing a complete shut-off of the gas output from both the gas burners and the ignition source feed from the safety electrovalve.
The second thermocouple informs the electronic control unit on the status of the flames, permitting the complete shut-off of the gas output from both the gas burners and the ignition source, obtaining the same effect as the closure of the safety electrovalve, but in this case under the control of the electronic control device.
Preferably, the at least one thermocouple, for example, the first and second thermocouples, are in contact with the flame of the ignition source, because said flame is in contact with all the flames of all the gas burners of the same cooking zone and therefore if it is extinguished it will be indicative that all the flames of all the gas burners of the cooking zone will be also extinguished.
The electronic control device may also issue a warning when the safety electrovalve closes due to accidentally extinguishing the flame. This warning can be a sound and/or light warning to the user and allow cooking to resume correctly.
The control device cannot prevent the safety electrovalve from closing if the thermocouple interrupts the signal emission due to the flame extinguishing but can detect the state of the flame and acting accordingly.
According to an alternative solution, one relay is interposed between the thermocouple and the safety electrovalve, and furthermore it is proposed that said relay is oversized in power, that is, intended to transmit electrical currents of a much higher intensity, which minimizes losses of the signal that the relay passes through.
Thus, the control device additionally integrates a system to interrupt said thermocouple signal by acting on the relay and thus being able to cause the safety electrovalve to close, causing the intentional shutdown of the gas burners. Said system is made up of said electrical relay activated by the control system and preferably oversized in power, for example by a factor of at least 100, or preferably oversized by at least a factor of 1000, to minimize signal losses.
As has been indicated a frequent problem in cooking units of this type is that the signal generated by the thermocouple is extremely weak, and this, combined with the losses caused by said signal during its transmission to the safety electrovalve, causes false positives that unnecessarily interrupt cooking. This loss of signal is especially significant in each electrical connection and in each device interposed between the thermocouple and the safety electrovalve, such as switches or the like.
Preferably said relay will be integrated in a printed circuit board that integrates the control device, thus saving connections and connection cables, and therefore reducing power losses.
The control unit may only detect the passage of a signal through said relay, or act on it to interrupt said signal, but in no case may it generate a signal in the relay that is transmitted to the safety electrovalve, replacing the signal generated by the thermocouple.
In any case, the use of the relay, or the use of first and second thermocouples allows the electronic control unit not to be part of the safety unit of the cooking unit, since its failure would not prevent the correct operation of the communication between the thermocouple and the safety electrovalve, therefore allowing the use of a simple and economic control unit.
This solution reduces the risk of false positives and therefore the risk of accidental shutdown. Furthermore, it allows the electronic control device itself to be used to control the complete switching on and off of the cooking unit, for example at the user’s request or at the end of cooking, by switching off the relay of by switching off the regulation electrovalves and the ignition source electrovalve, extinguishing all flames of the cooking zone and also triggering the closure of the safety electrovalve by the first thermocouple.
The proposed solution of including a relay between the thermocouple and the electrovalve, said relay being controlled by the control unit, in addition to avoiding “false positives”, can delay them at will for a certain time of confirmation, so that they do not act (in in the event of a punctual air flow, or other minor incidents) cutting off the gas supply, except when an uncontrolled gas leak actually occurs, establishing maximum and minimum margins adaptable to the industrial regulations for the approval of the cooking unit.
According to another aspect of the invention, the use of a single variable pitch regulating electrovalve is also proposed to control the gas flow of each individual gas burner. For example, if there are three burners, there will be three regulation valves with variable pitch.
Alternatively, the regulation electrovalve are several fixed-pitch electrovalves connected in parallel for each gas burner. For example, one fixed-pitch electrovalve configured to supply, when open, only 33% of the gas to the gas burner, and another fixed-pitched electrovalve configured to supply, when open, 67% of the gas to the gas burner. Opening one, the other or both, can provide 33%, 67% or 100% of the gas to the gas burner.
According to a proposed embodiment, the electronic control device also has a data input for modifying the stored regulation programs. Said data input is understood to be a physical data connection, such as a USB, LAN or similar input, or a wireless data connection, such as WIFI, BLUETOOTH or the like.
The data input may also be used to control a plurality of identical cooking units centrally or remotely through said data input.
It will be understood that said data input can be integrated in the equipment provided with the relay described herein, but it can also be included in a device without said relay.
It is also proposed in this invention that the control device determines the closing of the safety electrovalve in response to a combination of signals obtained from the at least one thermocouple and the food monitoring sensor and/or weight sensor. In this way, if there is a discrepancy between the readings obtained from the food monitoring sensor and the at least one thermocouple, for example due to a malfunction of any of said components, the control device can interrupt the cooking process causing directly or indirectly the closure of the safety electrovalve.
The above-mentioned food monitoring sensor may be:
The infrared sensor may be adapted to detect the temperature in the different regions of the cooking zone (which it covers in its entirety) in a differentiated way, and to transmit this information to the control device, thus allowing differentiated regulation of the regulating electrovalves of each individual gas burner, or even to detect the size of a cookware arranged on the cooking zone by means of the aforementioned detection of differentiated temperature, thus achieving that the control device applies a regulation program adapted to said cookware size, for example by turning off the outermost gas burner of a group of ring burners.
The camera may be a video camera for visible light. The cooking status of the food determined by the image recognition algorithm, the trained neural network, and/or the trained machine learning model may recognize the type of food contained in the cookware by its appearance, of may identify the cooking status by analysing changes in the food color, or may identify bubbles on a liquid contained in the cookware, indicative of a boiling process. This determination can be made by training the image recognition algorithm, the trained neural network, and/or the trained machine learning model with images of preceding cooking processes, associated with cooking status information, for example obtained from manual interventions of users on the cooking process. For example, a manual shut down of the cooking process is indicative of the end thereof, and the images obtained in that moment will be a reference of a finished cooking process.
The temperature probe can be, for example, a nail punched on a food product such meat, or can be a ball like element submerged in the food, for example boiling water, soup or cream.
The temperature probe may include different temperature sensors associated with different buoyancy elements configured to submerge at different depths in hot water, permitting the measurement of temperature at different depths.
The control device may also be configured to regulate the regulation electrovalves to maintain the temperature detected by food monitoring temperature at a target temperature determined by the regulation program, so that it may increase or decrease the gas flow to maintain said constant temperature, since the gas flow will affect the temperature of the cooked food differently depending on the amount of water remaining in the cookware, or the amount of wind that may be in the installation area, for example.
According to another embodiment, the different control programs of the electronic control device correspond to different kitchen recipes adapted to different amounts of food and to different sizes of cookware.
An interface such buttons, a screen and/or a touchscreen connected to the electronic control device, for example a screen integrated in the cooking unit or a screen integrated in a smartphone, tablet or similar device connected wirelessly to the electronic control unit, allows a user to select a regulation program adapted to the size of the cookware placed on the cooking zone. This controls how many of the gas burners are necessary for cooking a recipe and regulates the time and intensity of applying heat to the specific characteristics of a recipe, a size of utensil, and a specific amount of food.
Likewise, the food monitoring sensor or the weight sensor can be used by the electronic control unit to detect the presence of a cookware over the cooking zone, allowing cooking to start after placing a cookware in said cooking zone and receiving a command from a user.
Likewise, the electronic control device is configured to determine, by means of temperature readings from the food monitoring sensor or from weight measurements of the weight sensor, the intervention of a user on the cooking zone or the incorporation of ingredients, and to proceed automatically in application of the regulation program.
For example, a user will be able to select on the interface a control program adapted to the preparation of a paella-dish for six diners cooked in a paella-pan sixty centimetres in diameter, and after arranging the said paella-pan, with its ingredients inside, the cooking unit will be will be in charge of controlling the cooking process until it is completed without needing assistance, applying different temperature settings corresponding to different cooking phases, regulated by the applied regulation program, for example including an acoustic or light alarm to warn the user that cooking has been completed. Intermediate stages of cooking, such as adding an ingredient, may also be warned to the user by means of alarm signals.
The electronic control unit will be able to detect that said intermediate cooking operations have been carried out by the user, either because the user notifies it through the interface, or because the control unit detects a variation in the signals received for the food monitoring sensor or from the weight sensor, for example a sudden decrease in temperature when adding water or another ingredient in the cooking zone, a sudden weight variation, or a visual confirmation of such intervention.
The different control programs correspond to different cooking recipes and will therefore be adapted to different amounts of food and to different sizes of cookware. The electronic control device can deduce, by means of temperature readings from the food monitoring sensor or from the weight sensor, the size of the cookware placed on the cooking zone, and automatically selects a regulation program adapted to said size.
In a preferred embodiment the at least one gas burner will comprise a plurality of concentric circular (or other annular configuration) gas burners, in which case the ignition source is preferably a radial gas burner transversal to the other annular gas burners, and the safety electrovalve cuts off the supply of all gas burners including the ignition source.
In relation to the infrared sensor, it is also proposed that between said infrared sensor and the cooking zone a protective screen that integrates a germanium glass that is transparent to the infrared and resistant to temperatures of at least 200° C. is provided.
This protective screen will protect the infrared sensor from being damaged by exposure to excessive temperatures caused by cooking tasks. Different scenarios could cause such damage.
For example, if a flambé occurs, intentionally or accidentally setting fire to the contents of a cookware placed on the cooking zone, the flames could reach the infrared sensor and damage it or damage its protector if it were not resistant to high temperatures. Alternatively, a carelessly heated, high-temperature cookware could come into contact with the infrared sensor, damaging it or melting its shield if it were made of a fusible material such as plastic. In another scenario, superheated vapours, drops of oil or other high-temperature liquid from the surface of the cooked food, splashed on the infrared sensor could damage its lens or a hypothetical lens protector.
In any of these scenarios, the invention proposes a protective screen provided with an infrared-transparent germanium glass and resistant to temperatures of at least 200° C. that protects the infrared sensor and prevents the cooking unit from being damaged.
The infrared sensor is preferably housed in a protective housing arranged behind the protective screen.
The protective screen can also integrate a metallic screen around the infrared transparent element. In such a case, the metallic screen and the infrared transparent element can be flush with the face of the protective screen facing the cooking zone, thus facilitating the cleaning and hygiene of said protective screen.
According to an embodiment, the infrared transparent element is circular, is surrounded by a frustoconical and/or stepped perimeter annular face and is fitted into a complementary stepped and/or frustoconical circular opening provided in the metal screen. In this way, the infrared transparent element can be inserted into the complementary opening from the side not exposed to the cooking zone, being retained inside for example being pressed by the infrared sensor itself or another fixing element arranged in that face not exposed to the cooking zone. In this way, the infrared transparent element is fixed in position without the need for seals, frames, adhesives, or other fixing systems that could be damaged by heat.
It is also proposed that the infrared sensor is located at the end of a support arm, extended in elevation (so that the sensor can cover the entire visible surface of the food being cooked), attached to the rest of the cooking unit through a chassis, the entire assembly constituting a portable unit. Said arm could be detachable from the chassis for storage, maintenance, cleaning, transport, or repair.
It is also contemplated that the chassis of the cooking unit includes different fixing positions of the arm, thus allowing said arm to be mounted in different positions, for example depending on the place in which to position the cooking unit, the available space, or other criteria.
Said support arm will preferably be metallic and its distal end will constitute said metallic screen of the protective screen, the infrared sensor being hidden with respect to the cooking zone by the distal end of said arm but being able to observe that cooking zone through an opening made in the aforementioned arm protected by the infrared transparent and heat resistant element.
The proposed cooking unit can further include, in connection with the electronic control device, a level sensor configured to detect any deviation level from horizontal of at least part of the cooking unit including a cookware support placed below the cooking zone for supporting a cookware thereon, the electronic control device being configured to automatically correct the detected deviation level by automatically actuating level adjusting devices of the cooking unit adapted to modify the inclination of at least part of the cooking unit, or to notify a user of a necessary manually adjustment the level adjusting devices of the cooking unit adapted to modify the inclination of at least part of the cooking unit.
The proposed cooking unit may also include at least one vibrator device attached to at least a portion of the cooking unit including a cookware support placed below the cooking zone for supporting a cookware thereon, the vibrator device being controlled by the electronic control device in application of the regulation programs. The vibration can be implemented as part of the cooking process, for example to mix the ingredients, or to prevent an adhesion of some ingredients to the cookware during the cooking process.
According to another embodiment, the cooking unit may include an auxiliary assembly comprising at least the regulation electrovalves, the ignition source electrovalve, the safety electrovalve and the electronic control unit, the auxiliary assembly and the components included therein being connected to the rest of the cooking unit through releasable connections. All the releasable connections between the components included in the auxiliary assembly and other components external to the auxiliary assembly are preferably axial releasable connections parallel to each other.
The cooking unit can further include an electric battery supplying electrical energy at least to the electronic control device and to the sensors connected thereto.
It will also be understood that any range of values offered may not be optimal in their extreme values and may require adaptations of the invention for said extreme values to be applicable, said adaptations being within the reach of a person skilled in the art.
Other characteristics of the invention will appear in the following detailed description of an exemplary embodiment.
The foregoing and other advantages and characteristics will be more fully understood from the following detailed description of an exemplary embodiment with reference to the accompanying drawings, which should be taken in an illustrative and not limitative way, in which:
The attached figures show embodiments of the present invention in an illustrative but not limitative manner.
According to an exemplary embodiment shown in
Although circular burners have been illustrated in the drawings, they may adopt other annular configurations, including one or more elements.
Each circular tube is connected to a separate gas supply conduit, each of said supply tubes being connected to a single variable pitch regulation valve 3, or two several fixed-pitch regulation electrovalves 3 connected in parallel as shown in
The use of variable pitch regulation valves 3 according to an embodiment allows a precise regulation of the gas flow supplied. The use of two fixed-pitch regulation electrovalves connected in parallel, for example one adjusted to provide 33% of the total maximum gas flow and the other adjusted to provide 67% of the total maximum gas flow, allow the regulation of three different intensity levels (33%, 67% or 100%) in an easy, reliable and unexpensive manner.
The cooking unit is proposed to also include an electronic control device or control unit 7, integrating, for example, a PLC (programmable logic controller), or any other type of programmable electronic device with the capacity to apply a regulation program. Said electronic control device 7 will have an interface 8 that will allow a user to be informed of different control parameters of the cooking unit, also allowing the user to select some regulation parameters of the electronic control device 7, such as control sequences for the gas burners 1 adapted to different cooking recipes, or to different sizes of cookware.
The electronic control device 7 is connected to regulating electrovalves 3, so that the gas flow supplied to gas burners 1 by said regulating electrovalves 3 is controlled by the electronic control device 7 and corresponds to the program of regulation selected.
The electronic control device 7 is also connected to an ignition source electrovalve 13.
The cooking unit also includes a food monitoring sensor 5 for each cooking zone configured to detect the cooking status of the food contained in the cooking zone, and/or a weight sensor 15 for each cooking zone configured to detect weight variations on the cooking zone.
According to the embodiment shown in
Alternatively, or additionally, the food monitoring sensor 5 may be a temperature probe placeable on the cooking zone in thermal contact with, or embedded in, a food placed on the cooking zone for monitoring the food temperature, the temperature probe being connected to the electronic control device by wire or by wireless connection. For example, in
The weight sensors 15 may be arranged to detect weight increases of the cooking unit, or parts thereof, for example being arranged on legs of the cooking unit or on a cookware support, configured to hold a cookware in the cooking zone, to detect the presence of a cookware, the increase in weight of the cookware by the addition of ingredients, or the reduction in weight of the cookware by the evaporation of water.
The electronic control device 7 can be configured to notify a user of the need to incorporate a quantity of a new ingredient in the area of cooking and to notify the user when the increase in weight detected by the weight sensor 15 coincides with the amount of the new ingredient to be incorporated so that it stops the incorporation of said new ingredient. Also, the evaporation of water can be monitored by the weight sensor 15, for example to determine when the water has been completely evaporated and the flames shall be turned off.
The food monitoring sensor 5 and/or the weight sensor 15 is connected to the electronic control device 7 to which it transmits the collected information, and said electronic control device 7 determines the precise regulation of the regulation electrovalves 3 in response to the readings obtained by the food monitoring sensor 5 and/or by the weight sensor and in application of the program selected by the user through the interface 8.
As a result, a user will be able to place a cookware on the cooking zone, include the required ingredients in the necessary quantities, which can be notified to the user through the interface 8 of the electronic control device 7, and activate the cooking. The cooking unit will be in charge of all the regulation and control of the intensity of the heat supplied to the food until its cooking is completed without requiring further user intervention.
The electronic control device 7 also includes a data input 9, in this case a USB port or equivalent, which allows updating the control programs or incorporating new control programs, such as new recipes. Alternatively, it is contemplated that the data entry is remote by wireless means, for example by means of a WIFI, Bluetooth, 3G, 4G, 5G or similar communication protocol.
All the regulating electrovalves 3 receive a gas supply from the same gas source, for example a fixed installation connected to the gas distribution network, or to a gas supply cylinder, however a safety electrovalve 4 will be interposed that will allow the gas supply to the regulation electrovalves 3 to be completely closed, and with them also to all the gas burners 1. Also, the ignition source is feed with gas from the same gas source through the safety electrovalve 4.
The safety electrovalve 4 is a safety element that closes the gas passage in the event of an accidental extinguishing of the flame of the gas burners 1 and of the ignition source 2 that allows a free exit of the gas. Said safety electrovalve 4 will be controlled and activated by a thermocouple 6 in thermal contact with the cooking zone and connected to safety electrovalve 4.
Typically, the ignition source 2 will be a radial gas burner transversal to the other annular gas burners 1, which will have a constant gas supply regardless of the regulation of the regulation electrovalves 3, that is to say that when all the regulation electrovalves 3 are completely closed ignition source 2 will continue to receive a sufficient gas supply to keep a flame burning. Said gas supply from the ignition source 2 is regulated from the safety electrovalve 4, so that the closure of said safety electrovalve 4 will also close gas supply to the ignition source 2. Between the ignition source 2 and the safety electrovalve 4 an ignition source electrovalve 13, controlled by the electronic control device is also included, allowing the electronic control device to completely closing all the gas feed to the cooking zone without intervening on the safety electrovalve.
To control the activation of the safety electrovalve 4, a thermocouple 6 is arranged in thermal contact with the cooking zone that is to say in thermal contact with the heat produced by the flames of the gas burners 1 or of the ignition source 2. In the present embodiment, the thermocouple 6 is in thermal contact with the flame of the ignition source 2
Subjected to said heat, the thermocouple 6 generates a weak electrical signal that is transmitted to the safety valve 4 through a conductor cable. When the thermocouple 6 cools down, supposedly due to the accidental extinguishing of the flame of the gas burners 1 or of the ignition source 2, the electrical signal is interrupted and the safety electrovalve 4 closes the gas passage completely closing off the cooking unit.
The electrical signal generated by the thermocouple 6 is extremely weak and the transmission of said signal to the safety electrovalve 4 suffers from losses due to the electrical resistance of the interposed elements, causing frequent false positives that close the gas supply unnecessarily. Furthermore, typically said conductor cable also includes a switch that allows a voluntary closing of the safety electrovalve 4 interrupting the electrical signal, said switch and its connections adding greater electrical resistance to the transmission of the signal.
In the present embodiment, it is proposed to dispense with said switch and to place, between the thermocouple 6 and the safety electrovalve 4, only one relay 10, preferably an oversized relay 10 by at least a factor of 1000. This allows reducing the power losses of the electrical signal generated by thermocouple 6, minimizing the connections between the two elements.
The relay 10 is in turn connected to the electronic control device 7 thus allowing the electronic control device 7 to detect the signal generated by the thermocouple 6. Thus, if the electrical signal generated by thermocouple 6 is interrupted, the electronic control device 7 can interrupt the regulation program that is running, and also notify the user that such interruption has occurred, for example by means of a light or acoustic warning signal.
The electronic control device 7 cannot prevent the safety electrovalve 4 from closing in the event that the signal generated by the thermocouple 6 is interrupted, however, it can intentionally interrupt said signal through the relay 10. This allows that the electronic device control 7 can actuate the closing of the safety electrovalve 4, and therefore control the total closure of the gas supply, for example when the electronic control device 7 is turned off, or when the selected program stops being applied.
A simplified version of this solution, but including a single gas burner, is shown schematically in
According to an alternative embodiment shown in
Preferably, the entire assembly that constitutes the cooking unit is supported on a chassis 11 (see
Said arm 12 will be, for example, a metal plate whose upper end will be inclined at an angle, facing towards the centre of the cooking zone. At said upper end there will be an opening where an infrared transparent element 21 will be housed, after which the infrared sensor will be placed. This construction allows the distal end of the arm 12 to act as a protective screen 20, which will preferably be metallic or made of another heat-resistant and flame-retardant material, protecting the infrared sensor from heat or possible flames occurring in the cooking zone, since said infrared sensor 5 will be behind the protective screen 20.
The transparent infrared element 21, which will preferably be a germanium glass, is resistant to temperatures above 200° C., and allows infrared light to pass through it, not interfering with the infrared sensor.
According to a preferred construction, the distal end of the arm 12, which acts as a protective screen 20, will have a wider frustoconical hole on the side remote from the cooking zone. In this frustoconical hole a germanium glass will also be inserted with a frustoconical shape complementary to the shape of the hole. Subsequently, the infrared sensor is superimposed on said germanium glass and is fixed on the back of said protective screen 20, thus being retained in its position without the need for adhesives that could be damaged by high temperatures.
According to a further proposed embodiment, shown schematically in
In an alternative embodiment, it is provided that each gas burner 1 is supplied with gas through a single variable-pitch regulation valve 3.
In this embodiment, a single gas burner 1 has been shown in each cooking zone, but obviously each cooking zone can consist of multiple gas burners 1, similar to the one shown in
The gas burners 1 of each cooking zone will have an associated food monitoring sensor 5, monitoring the corresponding cooking zone and at least one thermocouple 6 to control that the flame of the gas burner 1 or of the ignition source 2 is not accidentally extinguished.
According to the embodiment shown in
In an exemplary embodiment, all food monitoring sensors, all regulating electrovalves 3 and all relays 10 will be connected and controlled by a single centralized electronic control device 7, thus reducing costs and improving control.
Also.
In this example the presence of a safety electrovalve 4 associated with the burners of each cooking zone has been shown, however it is understood that there could be a single general safety electrovalve 4 that would close the gas supply to all burners if any of thermocouples 6 will detect a flame out.
Although in
It is also foreseen that the cooking unit also integrates, in connection with the electronic control device 7, various sensors selected from:
In one embodiment, an electric battery integrated in the cooking unit or associated with the electronic control device 7 is provided, which will supply electrical energy to the latter and to the sensors connected to it.
According to an exemplary embodiment, the cooking unit further includes a vibrating device attached to the cooking unit or to a cookware support configured to hold a cookware in the cooking zone, the vibrating device being controlled by the electronic control device 7 in application of the regulation programs. In this exemplary embodiment, the cooking unit also preferably includes a cookware fixing device which can be selected from:
In accordance with another embodiment, it is provided that the electronic control device 7 of the cooking unit includes a proportional, integral and derivative controller configured to regulate the regulating electrovalves 3, adapting its flow rate, increasing it if it is below a target temperature or threshold value (referenced by the food monitoring sensor 5) or decreasing it if it exceeds the mentioned target temperature. This increase or decrease may be a maximum or a minimum depending on the orders that are established by the control unit 7, according to the program executed by said unit.
In relation to structural aspects of the cooking unit, it has also been provided that all the elements of the cooking unit other than the gas burners 1 form an auxiliary assembly, where the gas burners 1 are housed and connected to said auxiliary assembly and connected to the corresponding regulation valves 3 only by releasable connections accessible from the outside of the auxiliary assembly, and where the auxiliary assembly has a dimensioned passage for the free extraction of the gas burners 1 from the interior therethrough.
Likewise, and to facilitate maintenance tasks, in one embodiment, it is provided that each gas burner 1 is connected to a corresponding regulation valve 3 by means of a rigid duct that is interspersed with a section of gas injector, which contains an injector adapted to the type of gas supplied to the gas burner 1, the injector section being connected to the rest of the rigid duct by releasable connections and the injector section being removable in a transverse direction with respect to the rigid duct.
Alternatively, it is contemplated that the gas burners 1 and the associated elements that make up each cooking zone can be modules that can be added at will by connecting them to a central module that contains the electronic control device 7 and optionally also the regulation, ignition source and safety electrovalves 3, 13 and 4.
It will be understood that the different parts constituting the invention described in one embodiment can be freely combined with the parts described in other different embodiments even though said combination has not been explicitly described, if there is no harm in the combination.
| Number | Date | Country | Kind |
|---|---|---|---|
| U201731346 | Nov 2017 | ES | national |
| U201731347 | Nov 2017 | ES | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16761832 | May 2020 | US |
| Child | 18120082 | US |
