GAS COOKING APPLIANCE AND ASSOCIATED METHOD

Abstract

 Gas cooking appliance comprising a plurality of gas burners (B1-B3), a gas valve (30), an electrode (10) and a flame sensor (20) associated with each burner (B1-B3), at least one electric switch (40), and a control unit (100). The control unit (100) is configured to carry out an ignition step of at least one burner (B1-B3) when the at least one switch (40) is actuated for igniting said at least one burner (B1-B3), during said ignition step the electrodes (10) and the flame sensors (20) of at least said at least one burner (B1-B3) being activated, the control unit (100) being also configured to carry out a monitoring step after the ignition step, during said monitoring step the control unit (100) sequentially monitoring in time cycles T the presence or absence of flame in the burners (B1-B3) which have been lit during the ignition step.

Description

TECHNICAL FIELD

[0001] The present invention relates to gas cooking appliances and to methods for controlling the presence or absence of flame of a plurality of gas burners implemented with said gas cooking appliances.

PRIOR ART

[0002] Gas cooking appliances comprising a gas conduit feeding a plurality of gas burners with gas, and a gas valve for regulating the gas flow reaching each gas burner, are known. The flame in the gas burner is usually ignited, in particular in gas barbecues, by acting on an ignition electrode by means of a push-button, once the passage of gas to the burner has been opened, which can be manual. In other embodiments of gas cooking appliances, said appliances comprise a control unit electrically connected to ignition electrodes associated with the gas burners, said gas cooking appliances also comprising flame sensors associated with each gas burner, which monitor the presence or absence of flame in the burners, during, and subsequently after the flame is ignited. This monitoring of the flame is carried out in simultaneously in the different burners, so the cooking appliance needs a significant amount of energy to be able to do it.

[0003] US2016/0348916A1 describes a gas cooking appliance comprising a plurality of gas burners, an electrode associated with each burner to ignite the flame in said burner when it is activated, a flame sensor associated with each burner for monitoring the presence or absence of the flame when it is activated, the flame sensor being configured to provide a detection signal based on the presence or absence of the flame, a gas valve for regulating the gas flow reaching each burner from a gas conduit, an electric switch associated with each actuator and configured to be activated when the actuator is actuated, and a control unit electrically powered at a voltage V, and electrically connected to the electrodes, the flame sensors and the switches, which is activated when at least one of the switches is activated, the control unit activating the electrodes and the flame sensors of the burners , the control unit determining the presence or absence of flame produced in the gas burners, based on the reception of the detection signals sent by the flame sensors. The gas valves comprise a safety electromagnetic unit, and are electrically connected to the control unit, needing a continuous electrical supply for their operation.

DESCRIPTION OF THE INVENTION

[0004] The object of the invention is to provide a gas cooking appliance and a method for controlling the presence or absence of flame of a plurality of gas burners implemented with said gas cooking appliance, as defined in the claims.

[0005] One aspect of the invention relates to a gas cooking appliance comprising a plurality of gas burners, an electrode associated with each burner for generating sparks next to said burner when it is activated and a flame sensor associated with each burner for monitoring the presence or absence of the flame when it is activated, the flame sensor being configured to provide a detection signal based on the presence or absence of the flame. The gas cooking appliance also comprises a gas valve associated with each burner for regulating the gas flow reaching the corresponding burner from a gas conduit, and at least one electric switch associated with an actuator and configured to be activated when the actuator is actuated.

[0006] The gas cooking appliance also comprises a control unit electrically connected to the electrodes, the flame sensors and the switch, said control unit being configured for monitoring the presence or absence of flame produced in the gas burners based on the reception of the detection signals provided by the flame sensors.

[0007] The control unit is configured to carry out an ignition step of at least one burner when the at least one switch is actuated for igniting said at least one burner, during said ignition step the electrodes and the flame sensors of at least said at least one burner being activated. The control unit is also configured to carry out a monitoring step after the ignition step, during said monitoring step the control unit sequentially monitoring in time cycles T the presence or absence of flame in the burners which have been lit during the ignition step, monitoring the detection signal of each flame sensor associated to said burners one at a time during each of the repeating time cycles T.

[0008] Another aspect of the invention relates to a method for controlling the presence or absence of flame of a plurality of burners implemented with a gas cooking appliance like the one defined above.

[0009] The gas cooking appliance and the method implemented in the gas cooking appliance of the invention allows monitoring the gas burners consuming low energy due to the sequential monitoring of said gas burners in time cycles T. Thus, only one burner is monitored from the control unit each time, only its associated flame sensor being activated at a time. When the defined time cycle T, which can be that defined by the standard of gas appliances, elapses, all the burners which have been lit during the ignition step will have been monitored and the monitoring will start again.

[0010] As a result of such low energy consumption, the gas cooking appliance of the invention can be supplied with commercial use batteries, as for example two AA batteries. Thus, long cooking work periods are obtained with the gas cooking appliance, of more than 300 hours, with a required electric power of less than 0.001w.

[0011] These and other advantages and features will become evident in view of the figures and the detailed description.

DESCRIPTION OF THE DRAWINGS

[0012] 

Figure 1 shows a schematic view of a first embodiment of a gas cooking appliance according to the invention, which in this case corresponds to a gas barbecue.

Figure 2 shows a partial schematic view of the gas cooking appliance of Figure 1.

Figure 3 shows an exploded side view of the assembly formed by a gas valve and an electric switch associated with the gas valve, of the gas cooking appliance of Figure 1.

Figure 4 shows a schematic view of the control unit of the gas cooking appliance of Figure 1.

Figure 5 shows a diagram relating the sequence of monitoring of the flame of gas burners of a gas cooking appliance in a time cycle T, with the elapsed time.

Figure 6 shows a diagram relating an electric switch and the control unit of the gas cooking appliance of Figure 1 with time, wherein after an inactive time Ti of the gas cooking appliance the control unit is deactivated, and it is activated again after deactivating and reactivating the switch.

Figure 7 shows a flow chart of a first embodiment of the method of the invention for controlling the presence or absence of flame of the gas burners of the gas cooking appliance of Figure 1.

Figure 8 shows a schematic view of a second embodiment of a gas cooking appliance according to the invention.

Figure 9 shows a partial schematic view of the gas cooking appliance of Figure 8.

Figure 10 shows a schematic view of a third embodiment of a gas cooking appliance according to the invention.

Figure 11 shows a partial schematic view of the gas cooking appliance of Figure 10.

Figure 12 shows a flow chart of a second embodiment of the method of the invention for controlling the presence or absence of flame of the gas burners of the gas cooking appliance of Figures 8 and 10.

DETAILED DESCRIPTION OF THE INVENTION

[0013] Figure 1 shows a schematic view of a first embodiment of a gas cooking appliance 200 according to the invention, which in this case corresponds to a gas barbecue. Figure 2 shows a partial schematic view of the gas cooking appliance 200 of Figure 1, Figure 3 shows an exploded side view of the assembly formed by a gas valve 30 and an electric switch 40 associated with the gas valve 30 of the gas cooking appliance 200 of Figure 1, and Figure 4 shows a schematic view of the control unit 100 of the gas cooking appliance 200 of Figure 1.

[0014] The gas cooking appliance 200 comprises a plurality gas burners B1-B3, an electrode 10 associated with each burner B1-B3 for generating sparks next to said burner B1-B3 when it is activated, and a flame sensor 20 associated with each burner B1-B3 for monitoring the presence or absence of the flame when it is activated, the flame sensor 20 being configured to provide a detection signal based on the presence or absence of the flame.

[0015] The gas cooking appliance 200 also comprises a gas valve 30 associated with each burner B1-B3 for regulating the gas flow reaching the corresponding burner B1-B3 from a gas conduit 32.

[0016] The gas cooking appliance 200 also comprises at least one electric switch 40 associated with an actuator 31 and configured to be activated when the actuator 31 is actuated, and a control unit 100 electrically connected to the electrodes 10, the flame sensors 20, and said at least one switch 40, the control unit 100 being configured for monitoring the presence or absence of flame produced in the gas burners B1-B3 based on the reception of the detection signals provided by the flame sensors 20. Preferably the control unit 100 is activated when said at least one switch 40 is activated.

[0017] The control unit 100 is configured to carry out an ignition step of at least one burner B1-B3 when the at least one switch 40 is actuated for igniting said at least one burner B1-B3, during said ignition step the electrodes 10 and the flame sensors 20 of at least said at least one burner B1-B3 being activated.

[0018] The control unit 100 is also configured to carry out a monitoring step after the ignition step, during said monitoring step the control unit 100 sequentially monitoring in time cycles T the presence or absence of flame in the burners B1-B3 which have been lit during the ignition step, monitoring the detection signal of each flame sensor 20 associated to said burners B1-B3 one at a time during each of the repeating time cycles T. Said predefined time cycle T is preferably of 10 seconds as indicated by the standard of gas appliances. During the monitoring step, when said time cycle T elapses all the burners B1-B3 which have been lit during the ignition step will have been monitored and a new cycle will start again. Monitoring the burners sequentially needs much less energy consumption than doing it simultaneously in a plurality of burners.

[0019] Since the monitoring of the presence or absence of flame in the burners B1-B3 is sequential, the gas cooking device 200 needs much less electrical energy for its operation. As a result of such a low energy consumption, the control unit 100 can be electrically powered only from a power source 110 formed by two batteries arranged in series, preferably of the AA type, at a voltage V of 1.5 volts each, defining a power supply voltage of the control unit 100 of 3 volts. Thus, long cooking work periods are obtained with the gas cooking appliance 200, of more than 300 hours, with a required electric power of less than 0.001w.

[0020] Preferably during the ignition step the control unit 100 is configured to activate the electrodes 10 and the flame sensors 20 associated to all burners B1-B3, i.e. independent of which gas valves 30 associated to the burners B1-B3 have been open by the user, all the electrodes 10 and the flame sensors 20 are activated by the control unit 100 during said ignition step. In this way, it is not necessary for the control unit to know which gas valves associated to the gas burners have been activated. All the electrodes 10 are activated simultaneously, while the flame sensors 20 are activated sequentially. So, during the ignition step, the activation of the electrodes 10 and the flame sensors 20 is carried out so that it is alternated simultaneous activation of all electrodes 10 with a sequential activation of flame sensors 20, so that each flame sensor 20 is activated one at a time between the activation of the electrodes 10.

[0021] In the first embodiment of the gas cooking appliance 200, each gas valve 30 is a manually driven gas tap comprising the actuator 31 which is a drive shaft. Said gas valve 30 is of the type comprising a rotary gas flow-regulating member (not shown in the figures), which is arranged in the body of the gas valve 30, and the actuator 31 is mechanically coupled to said regulating member. The gas valve 30 comprises a gas inlet fluidically communicated with the gas supply 33, a gas outlet fluidically communicated with the associated burner B1-B3, and the regulating member is fluidically arranged between the gas inlet and outlet. The manual actuator 31 is mechanically coupled to the regulating member and allows regulating the gas flow in the gas valve 30 when it is actuated. Each gas valve 30 comprises a knob 34 which is coupled to the actuator 31 at one end, and the user can manipulate said gas valve 30 by acting on the knob 34.

[0022] In this first embodiment of the gas cooking appliance 200, the actuator 31, and therefore the regulating member, rotates in an angle of rotation between an initial position corresponding to an angular position of 0°, in which the gas valve 30 is closed and does not supply any gas flow to the associated burner B1-B3, and a final position corresponding to an angular position of for example 270°, in which the gas valve 30 supplies a determined gas flow, which is a minimum gas flow. The gas supply flow at the outlet of the gas valve 30 starts at an angular position of 45°, reaching a maximum gas flow at an angle of 90°. Then, and with the rotation, the gas flow decreases by an intermediate gas flow rate, until reaching at 270° the minimum gas flow. The range of angular positions is referred to as range of actuation, corresponding to the actuator 31, in this embodiment of the gas cooking appliance 200, a first range of actuation of 270°. The range of angular positions corresponding to a gas flow which is supplied to the corresponding associated burner B1-B3 from the gas valve 30 is smaller, between 45° and 270°.

[0023] In the first embodiment, the gas cooking appliance 200 comprises a switch 40 associated with each gas valve 30, each of said switches 40 being activated by the corresponding actuator 31 at any point of a second range of actuation, the second range of actuation being less than or equal to the first range of actuation. So, each switch 40 is associated with a corresponding actuator 31 of a gas valve 30, as shown in Figure 3, for example, mechanically by means of a cam (not shown in the figures) which in this embodiment of the gas cooking appliance 200 comprises the switch 40 therein. The actuator 31 of the gas valve 30 has in this embodiment a D-shaped area which is coupled to the cam of the switch 40, such that they both rotate integrally. The coupling is configured such that the switch 40 is activated, and therefore closes an electric circuit, in a second range of actuation, from for example an angle of 30°, before the gas flow starts to exit, to 270°, which is smaller than the first range of actuation.

[0024] In this embodiment of the gas cooking appliance 200, the switches 40 are electrically connected with the control unit 100, each of the switches 40 being connected to the control unit 100 by means of a first electrical conductor common to all the switches 40, and a second individualized electrical conductor for each of the switches 40 (see in Figure 2 the connections of the electrical conductors), such that the activation of a switch 40, the respective associated actuator 31 of which has been actuated, allows the activation of the control unit 100. Thus, the control unit 100 receives the signals of the switches 40 which have been activated, the control unit 100 knows which switch 40 has been activated, and therefore with which burner B1-B3 is associated, and the control unit 100 knows which gas valves 30 have been operated to regulate the gas flow towards the associated burners B1-B3.

[0025] Although in this first embodiment the control unit 100 knows which gas valves 30 have been operated to regulate the gas flow towards the associated burners B1-B3, as explained before, when a switch 40 is actuated for igniting the associated burner B1-B3, the control unit 100 preferably activates the electrodes 10 and the flame sensors 20 of all burners B1-B3. In another embodiment of the gas cooking appliance 200, the control unit 100 could activate only the electrodes 10 and the flame sensors 20 of the burners B1-B3 the respective associated switches 40 of which have been activated.

[0026] In this first embodiment the gas cooking appliance 200 also comprises a bistable gas valve 50, of the ON-OFF type, arranged in the gas conduit 32, fluidically communicating a gas supply 33 with the gas valves 30, the valve 50 being electrically connected to the control unit 100. The valve 50, when it is in a stable open position, not consuming electric current in the position, allows the passage of gas towards the gas valves 30, and when it in a stable closed position, prevents the passage of gas towards said gas valves 30, the control unit 100 acting on the valve 50 to make it pass from a stable open position to a stable closed position, and vice versa, by means of current pulses. The control unit 100 is configured to open the valve 50, and arrange it in the stable open position when the gas cooking appliance 200 is turned on, sending an electric current pulse to the valve 50 when a switch 40 is activated, starting from the situation in which the gas cooking appliance 200 is turned off. The gas flow can thus reach the gas valves 30.

[0027] The valve 50 comprises a manual actuator 51 accessible from the outside and configured to arrange the valve 50 in the stable open position manually. Thus, if the power source 110, the two AA batteries, has been used up without being able to replace it, or if it has been spoilt, leaving the gas cooking appliance 200 without its energy supply, the gas cooking appliance 200, unlike the cooking appliance described in US2016/0348916A1, can be used to carry out cooking processes. To that end, the user will manually press the manual actuator 51 of the valve 50, opening the passage of gas towards the gas valves 30, and will ignite the flame in the burners B1-B3 by means of a match, a lighter, etc.

[0028] In this first embodiment of the gas cooking appliance 200, each electrode 10 and each flame sensor 20 associated with each respective burner B1-B3 form a single part, although in other embodiments they can be independent parts which only require the adjustment of the corresponding electric connections with the control unit 100.

[0029] In this first embodiment the control unit 100 is configured to generate detection electric voltage signals at a voltage V1 of, for example, 100 volts, greater than the power supply voltage V, said detection voltage signals being sent to the flame sensors 20 for their activation to carry out the monitoring process. The voltage V1 allows the flame to be ionized and be electrically conductive, such that the control unit 100 can determine whether or not an electric current continuity exists, and thus determine if there is presence or absence of flame in the respective burner B1-B3. The control unit 100, which is electrically powered by means of the power source 110, comprises a management unit 102 managing the control functions assigned to the control unit 100, and comprises a multiplexer. The control unit 100 also comprises a flame detection device 101 electrically connected to the flame sensors 20, which is electrically powered at the voltage V. The detection device 101 is electrically communicated with the management unit 102, and comprises a voltage booster which allows increasing the voltage from the voltage V to the voltage V1, and which generates the detection voltage signals at said voltage V1 which the multiplexer sends in a multiplexed manner, sequentially, to each of the flame sensors 20 associated with each burner B1-B3. Thus, a single detection device 101 is enough to carry out the sequential monitoring function.

[0030] In this first embodiment the control unit 100 is also configured to generate ignition electric voltage signals at a voltage V2 of, for example, 10 kilovolts, greater than the power supply voltage V, said ignition voltage signals being sent to the electrodes 10 for their activation to generate sparks next to the corresponding burner B1-B3. The control unit 100 comprises a spark generator 103 electrically connected to the electrodes 10 and to the management unit 102, being electrically powered at the voltage V, the spark generator 103 comprising, in this embodiment of the gas cooking appliance 200, a high-voltage transformer which, powered at the voltage V, increases the voltage to the voltage V2, and generates the ignition voltage signals at said voltage V2 which are sent to each of the electrodes 10 associated with each burner B1-B3. Thus, in each electrode 10 a series of sparks is formed which allows igniting each burner B1-B3. With this configuration of the control unit 100, in this embodiment of the gas cooking appliance 200, the ignition voltage signals are sent to all the electrodes 10, although in another embodiment of the gas cooking appliance 200 the ignition voltage signals could only be sent to the burners B1-B3 the switches 40 of which have been activated.

[0031] In this first embodiment the control unit 100 also comprises a connection unit 104 electrically connected to the management unit 102 that receives the electrical conductors from the switches 40, said connection unit 104 sending the corresponding on-off signals to the management unit 102.

[0032] Figure 5 shows a diagram relating the sequence of the monitoring step, of burners B1-B3 of the gas cooking appliance of the first embodiment, in a time cycle T, with the elapsed cooking time. The sequencing is carried out such that the sending of the detection voltage signal to the flame sensor 20 and the reception of the detection signal from the flame sensor 20, in each burner B1-B3 from/to the control unit, is carried out in a concatenated manner in a time cycle t, the sum of times t of the burners B1-B3 being less than time cycle T. Thus, in the embodiment of the gas cooking appliance 200 described, the time cycle T is 10 seconds, which means that at least each 10 seconds each burner B1-B3 is monitored, and the time cycle t is less than 1 second. In this embodiment, the electric consumption is reduced at least to a tenth with respect to a gas cooking appliance without sequencing of the monitoring.

[0033] In this first embodiment, when the flame sensors 20 of the burners B1-B3 whose switch 40 has been activated send a flame presence detection signal to the control unit 100, the control unit 100 is configured to stop sending ignition voltage signals to the electrodes 10, because it means that said burners B1-B3 have been ignited and have a flame, so the ignition step is concluded. When a flame sensor 20, either in the initial ignition moment of the burners B1-B3 whose switch 40 has been activated, or subsequently after the flame has been ignited in said burners B1-B3, sends a flame absence detection signal, the control unit 100 is configured to again send ignition voltage signals to the electrodes 10 for a determined re-ignition time period Tr, which in this embodiment is 8 seconds.

[0034] Figure 6 shows a diagram relating an electric switch 40 and the control unit 100 of the gas cooking appliance 200 of the first embodiment with the time. In this first embodiment he control unit 100 is also configured to be deactivated, and therefore the gas cooking appliance 200 turned off, when, having at least one burner B1-B3 with a flame, there is no change of state in said switch 40 after an inactive time Ti has elapsed, when the control unit 100 receives a flame absence detection signal from a flame sensor 20 after the re-ignition time period Tr has elapsed, or when all the activated switches 40 have stopped being activated. In the embodiment of the gas cooking appliance 200 shown, the defined inactive time Ti is 3 hours. To activate the control unit 100 again, and therefore to start the gas cooking appliance 200 again, it is enough to deactivate a switch 40 which is activated and activate it again or activate a switch 40 which was not activated.

[0035] In this first embodiment, the gas cooking appliance 200 also comprises illumination means 60 and acoustic means 70 which inform the user about the state in which the gas cooking appliance 200 is. The illumination means 60 are arranged in the knobs 34, although in other embodiments of the gas cooking appliance 200 (not shown) they can be in other locations, such as for example the panel of the appliance 200, such that when any expected situation occurs which must be notified to the user, the illumination means 60 emit a light in the knobs 34 which can vary in colour and/or intensity and/or frequency. The notification to the user preferably occurs when the flame has been ignited in a burner B1-B3, when the flame has not been ignited in a burner B1-B3 after the re-ignition time Tr has elapsed, when in a burner B1-B3 which was ignited with a flame the respective flame sensor 20 sends a flame absence detection signal, or when, after closing the gas flow in the gas valves 30 by acting on the actuators 31 passing them to the closed position, a determined residual heat threshold is exceeded in the gas cooking appliance 200, this threshold being defined for example with respect to the cooking time elapsed in the gas cooking appliance 200. The acoustic means 70 can have the same function as the illumination means 60, being arranged in this embodiment of the gas cooking appliance 200 in the control unit 100.

[0036] In this first embodiment the control unit 100 also comprises a signal unit 105 electrically connected to the management unit 102 and to the illumination means 60 and the acoustic means 70, said signal unit 105 sending the corresponding signals to said illumination means 60 and said acoustic means 70.

[0037] The control unit 100 is connected, in this embodiment of the gas cooking appliance 200, to a communications unit 120 which is configured to be connected to other external electronic devices. The connection can be wireless from the control unit 100 by means of bluetooth, wifi, etc., with external devices such as temperature sensors, remote control 130, such as smartphone or tablet, etc., or can also be a cable connection, series connection, USB, etc., to devices such as the communications unit 120 with a touch screen, which can in turn furthermore have wireless connection to other external devices such as the temperature sensors, the remote control 130, such as a smartphone or tablet, etc.

[0038] Figure 7 shows in a flow chart the steps of an embodiment of the method for controlling the presence or absence of flame of the plurality of gas burners B1-B3 applied for example to the gas cooking appliance of the first embodiment. The method comprises:

• a step of activating the control unit 100 S1, comprising a phase of actuation of the actuator 31 P11 in which a knob 34 coupled to the actuator 31 is turned and the gas valve 30 is arranged in a range of actuation with gas flow, and a phase of activation of the switch 40 P12 in which the associated switch 40 is activated and the control unit 100 is activated,
• an ignition step S2 where the electrodes 10 and the flame sensors 20 associated with the burners B1-B3 are activated, for igniting the flame and for monitoring the presence or absence of the flame in the burners B1-B3. Preferably the control unit 100 activates all the electrodes 10 and the flame sensors 20 of the burners B1-B3 and monitors all the burners B1-B3. The activation of the electrodes 10 and the flame sensors 20 is carried out so that it is alternated a simultaneous activation of all electrodes 10 with a sequential activation of flame sensors 20, so that each flame sensor 20 is activated one at a time between the activation of the electrodes 10. The ignition step S2 comprises a repetitive sequence of sending of the ignition voltage signal to all the electrode 10 simultaneously, and sequentially sending of the detection voltage signal to a flame sensor 20 and the reception of the detection signal from said flame sensor 20, in each burner B1-B3 from/to the control unit 100. In another embodiment of the gas cooking appliance 200, the control unit 100 could only activate the electrodes 10 and the flame sensors 20 of the burners in which the respective associated switches 40 have been activated.
• a step of opening the passage of gas S3, for igniting the flame in the burners B1-B3, comprising an opening phase P31 wherein the control unit 100 arranges the valve 50 in a stable open position, and a gas exit phase P32, in which the gas flows from the gas conduit 32 towards the gas valves 30, and from the gas valves 30 towards the associated gas burners B1-B3,
• a monitoring step S4 for determining the presence or absence of flame, based on the reception of the detection signals sent by the respective flame sensors 20, in those burners B1-B3 which have been lit during the last ignition step S2. The monitoring step S4 is carried out sequentially in time cycles T, such that only one burner B1-B3 is monitored each time. The sequencing is preferably carried out such that the sending of the detection voltage signal to the flame sensor 20 and the reception of the detection signal from the flame sensor 20, in each burner B1-B3 from/to the control unit 100, is carried out in a time cycle t, the sum of times t of the burners B1-B3 being less than time cycle T. The monitoring step S4 comprising a flame existence verification phase P41, wherein the decision is made to:
  • carry out a re-ignition phase P411 of the burner B1-B3 for a determined re-ignition time Tr, if the control unit 100 receives a flame absence detection signal from the flame sensor 20, or to
  • carry out a deactivation phase of the electrodes 10 P412 if the control unit 100 receives a flame presence detection signal from all the flame sensors 20,
• a step of turning off the gas cooking appliance 200 S5, deactivating the control unit 100, the step S5 comprising:
  • a turning off phase P51 if once the re-ignition time Tr of the re-ignition phase P411 has elapsed, the flame in the burner B1-B3 has not been ignited, and
  • an activity verification phase P52 of the activity of the gas cooking appliance 200, after the deactivation phase P412 of the electrodes 10, comprising a verification phase of the activated switches 40 P521 wherein:
    • if all the switches 40 are deactivated, the turning off phase P51 is carried out after verifying in a residual heat verification phase P5211 that a determined threshold is not exceeded in the gas cooking appliance 200, and
    • at least one switch 40 is kept activated and the respective associated burner B1-B3 is kept ignited and with a flame, a verification phase of the active time Ti of the gas cooking appliance 200 P5212 is carried out, in which:
      • the turning off phase P51 is carried out, when the determined time Ti has elapsed without a change of state of at least one switch 40, or
      • an activity continuation phase P52121 is carried out, returning to the flame existence verification phase P41,
  • a closing phase P53 before the turning off phase P51, the valve 50 passing to a stable closed position preventing the passage of gas by means of the control unit 100, and
• a step of re-starting the gas cooking appliance 200 S6, after the turning off phase P51 carried out in the re-ignition phase P411, or after the turning off phase P51 carried out after the verification phase of the activity of the gas cooking appliance 200 P5212, an activated switch 40 being deactivated and activated again, or activating a switch 40 which was deactivated.

[0039] Figure 8 shows a schematic view of a second embodiment of a gas cooking appliance 200. Figure 9 shows a partial schematic view of the gas cooking appliance 200 of Figure 8.

[0040] The gas cooking appliance 200 shown in this second embodiment differs from the gas cooking appliance of the first embodiment, in that it is a simpler gas cooking appliance 200, with fewer components, in which the electric switches associated with the gas valves 30 are dispensed with, comprising a single switch 40 associated with a respective actuator 31, the actuator 31 being a push-button. Consequently, in this second embodiment the control unit 100 does not know which gas valves 30 are actuated by the user.

[0041] In this second embodiment the switch 40 is electrically connected with the control unit 100, such that the activation of the switch 40, upon pressing the associated actuator 31, allows the activation of the control unit 100.

[0042] When the user wants to turn on the gas cooking appliance 200 of this second embodiment, a barbecue in the example shown, he/she presses the push-button 31 activating the switch 40, the control unit 100 being activated, and operates the gas valves 30, opening the passage for the gas flow, of the burners B1-B3 which he/she wants to turn on.

[0043] In this second embodiment, the control unit 100 is configured to carry out an ignition step while the switch 40 is activated, i.e., while the user maintains the push button 31 pressed. During said ignition step the electrodes 10 and the flame sensors 20 of all burners B1-B3 are activated. Said ignition step being carried out so that it is alternated a simultaneous activation of all electrodes 10 with a sequential activation of flame sensors 20, so that each flame sensor 20 is activated one at a time between the activation of the electrodes 10.

[0044] In this second embodiment, when the user stops pressing button 31, the control unit 100 is configured to carry out a monitoring step. During said monitoring step the control unit 100 sequentially monitors in time cycles T the presence or absence of flame in the burners B1-B3 which have been lit during the ignition step, monitoring the detection signal of each flame sensor 20 associated to said burners B1-B3 one at a time during each of the repeating time cycles T.

[0045] As in this second embodiment the control unit 100 does not know which gas valves 30 are actuated by the user, it is necessary to activate all the electrodes 10 and the flame sensors 20. Once the ignition step is concluded, the control unit only monitors the presence of flame in those burners which have been lit during the ignition step. This way it is possible to monitor the presence of flame in the burners consuming low energy due to the sequential and selective (only the burners which have been lit during the last ignition step are monitored) monitorization of the flame, with a gas cooking appliance 200 with a simple configuration with few components.

[0046] In this second embodiment the control unit 100 is configured to be deactivated when, after receiving the flame presence detection signal from the flame sensors 20 associated with those burners B1-B3 whose flame has been lit during the ignition step, it receives a flame absence detection signal from all flame sensors 20, a waiting time Te having elapsed.

[0047] In this second embodiment, the gas cooking appliance 200 also comprises illumination means 60 which inform the user about the state in which the gas cooking appliance 200 is, i.e. the state of the flame in each burner B1-B3. The illumination means 60 are arranged in the knobs 34, although in other embodiments of the gas cooking appliance 200 (not shown) they can be in other locations, such as for example the panel of the appliance 200.

[0048] Figure 10 shows a schematic view of third embodiment of a gas cooking appliance 200. Figure 11 shows a partial schematic view of the gas cooking appliance 200 of Figure 10. The gas cooking appliance 200 shown in this embodiment differs from the gas cooking appliance of the second embodiment, in that, as in the first embodiment of the gas cooking appliance, comprises an electric switch 40 associated with each actuator 31 of each gas valve 30, and configured to be activated when actuator 31 is actuated. As in the first embodiment, the actuator 31 is the drive shaft of the gas valve 30.

[0049] In this third embodiment of the gas cooking appliance 200, the switches 40 are electrically connected in parallel with the control unit 100, each of the switches 40 being connected to the control unit 100 by means of a first and second electrical conductors common to all the switches 40 (see in Figure 10 the connections of the electrical conductors), such that the activation of a switch 40, the respective associated actuator 31 of which has been actuated, allows the activation of the control unit 100. Thus, the control unit 100 receives signals from switches 40 that have been activated, but the control unit 100 does not know which switch 40 has been activated, and therefore does not know with which burner B1-B3 is associated, and the control unit 100 does not know which gas valves 30 have been operated to regulate the gas flow towards the associated burners B1-B3.

[0050] A feature of the gas cooking appliance 200 of this third embodiment, is that the switch 40 is only activated in a sector of the angular actuation range of the actuator 31, for example between 60 ° and 90 ° where a gas flow is defined, so that the user, to ignite the flame in a burner B1-B3, turns the knob 34 of the gas valve 30 and positions it in said sector.

[0051] In this third embodiment, the control unit 100 is configured to carry out an ignition step while the knob 34 is positioned in the defined sector of the angular actuation range of the actuator 31. During said ignition step the electrodes 10 and the flame sensors 20 of all burners B1-B3 are activated. Said ignition step being carried out so that it is alternated a simultaneous activation of all electrodes 10 with a sequential activation of flame sensors 20, so that each flame sensor 20 is activated one at a time between the activation of the electrodes 10. As in this second embodiment the control unit 100 does not know which gas valves 30 are actuated by the user, it is necessary to activate all the electrodes 10 and the flame sensors 20.

[0052] In this third embodiment, when the user turns the knob 34 positioning it in an angular position corresponding to a desired gas flow out of the sector where the switch 40 is activated, the control unit 100 is configured to carry out a monitoring step. During said monitoring step the control unit 100 sequentially monitors in time cycles T the presence or absence of flame in the burners B1-B3 which have been lit during the ignition step, monitoring the detection signal of each flame sensor 20 associated to said burners B1-B3 one at a time during each of the repeating time cycles T.

[0053] In this third embodiment, the gas cooking appliance 200 also comprises illumination means 60 which inform the user about the state in which the gas cooking appliance 200 is, i.e. the state of the flame in each burner B1-B3. The illumination means 60 are arranged in the knobs 34, although in other embodiments of the gas cooking appliance 200 (not shown) they can be in other locations, such as for example the panel of the appliance 200.

[0054] Figure 12 shows a flow chart of a second embodiment of the method of the invention for controlling the presence or absence of flame of the gas burners of the gas cooking appliance 200 of Figure 8 and 10. The method shown in Figure 12 comprises:

• a step of activating the control unit 100 S1, comprising an actuation phase of the actuator 31 P11 in which the actuator 31 is actuated, and an activation phase for activating the switch 40 P12 in which the associated switch 40 is activated and the control unit 100 is activated,
• while the switch 40 is activated an ignition step S2 where the electrodes 10 and the flame sensors 20 associated with the burners B1-B3 are activated. All the electrodes 10 and the flame sensors 20 of the burners B1-B3 are activated from the control unit 100. The activation of electrodes 10 and the flame sensors 20 is carried out such that it is alternated a simultaneous activation of all electrodes 10 with a sequential activation of flame sensors 20, so that each flame sensor 20 is activated one at a time between the activation of the electrodes 10. The ignition step S2 comprises a repetitive sequence of sending of the ignition voltage signal to all the electrode 10 simultaneously, and sequentially sending of the detection voltage signal to a flame sensor 20 and the reception of the detection signal from said flame sensor 20, in each burner B1-B3 from/to the control unit 100.
• a step of opening the passage of gas S3, for igniting the flame in the burners B1-B3, comprising an opening phase P31' for opening the gas valves 30, wherein the user acts on the gas valves 30, the associated burners B1-B3 of which are to be ignited with the flame, opening the passage of gas, and a gas exit phase P32, in which the gas flows from the gas conduit 32 towards said gas valves 30, and from said gas valves 30 towards the associated gas burners B1-B3,
• a monitoring step S4 of determining the presence or absence of ignited flame in the gas burners B1-B3 which have been lit during the last ignition step S2, based on the reception of the detection signals sent by the respective flame sensors 20, monitoring the detection signal of each flame sensor 20 associated to said burners B1-B3 one at a time during each of the repeating time cycles T. The monitoring step S4 comprising a flame existence verification phase P41, wherein the decision is made to:
  • carry out a waiting phase P413 of the burner B1-B3 during a determined waiting time Te, if the control unit 100 receives a flame absence detection signal from the flame sensor 20, after having received a flame presence detection signal, or
  • return to the flame existence verification phase P41, carrying out a loop function,
• a step of turning off the gas cooking appliance 200 S5, in which:
  • if the waiting time Te has elapsed without a flame in the burner B1-B3, a turning off phase P51 occurs in which the control unit 100 stops being electrically powered, and
  • if the waiting time Te, the burner B1-B3 being without a flame, has not elapsed, there is a return to the flame existence verification phase P41, carrying out a loop function.
• a step of re-starting the gas cooking appliance 200 S6, after the turning off phase P51, the activated switch 40 being deactivated and activated again, or activating the switch 40 which was deactivated.

[0055] In general, what is described for the method, in any of its embodiments and/or configurations, is also valid for the embodiments and/or configurations of the gas cooking appliance 200. Thus, the gas cooking appliance 200 comprises the adequate embodiment and/or configuration to support the corresponding embodiment and/or configuration of the method.

[0056] Similarly, what is described for the gas cooking appliance 200, in any of its embodiments and/or configurations, is also valid for the embodiments and/or configurations of the method. Thus, the method includes the embodiment and/or configuration suitable for the corresponding embodiment and/or configuration of the gas cooking appliance 200.

Claims

1. Gas cooking appliance comprising

- a plurality of gas burners (B1-B3),

- an electrode (10) associated with each burner (B1-B3) for generating sparks next to said burner (B1-B3) when it is activated,

- a flame sensor (20) associated with each burner (B1-B3) for monitoring the presence or absence of the flame when it is activated, the flame sensor (20) being configured to provide a detection signal based on the presence or absence of the flame,

- a gas valve (30) associated with each burner (B1-B3) for regulating the gas flow reaching the corresponding burner (B1-B3) from a gas conduit (32),

- at least one electric switch (40) associated with an actuator (31) and configured to be activated when the actuator (31) is actuated, and

- a control unit (100) electrically connected to the electrodes (10), the flame sensors (20) and the switch (40), the control unit (100) being configured for monitoring the presence or absence of flame produced in the gas burners (B1-B3) based on the reception of the detection signals provided by the flame sensors (20),

characterized in that the control unit (100) is configured to carry out an ignition step of at least one burner (B1-B3) when the at least one switch (40) is actuated for igniting said at least one burner (B1-B3), during said ignition step the electrodes (10) and the flame sensors (20) of at least said at least one burner (B1-B3) being activated, the control unit (100) being also configured to carry out a monitoring step after the ignition step, during said monitoring step the control unit (100) sequentially monitoring in time cycles T the presence or absence of flame in the burners (B1-B3) which have been lit during the ignition step, monitoring the detection signal of each flame sensor (20) associated to said burners (B1-B3) one at a time during each of the repeating time cycles T.

2. Gas cooking appliance according to claim 1, wherein the control unit (100) is configured to activate the electrodes (10) and the flame sensors (20) associated to all burners (B1-B3) during the ignition step, said activation being carried out so that it is alternated a simultaneous activation of all electrodes (10) with a sequential activation of flame sensors (20), so that each flame sensor (20) is activated one at a time between the activation of the electrodes (10).

3. Gas cooking appliance according to claim 1 or 2, wherein the control unit (100) is electrically powered from a power source (110) formed by at least one battery at the voltage V, the power source (110) being preferably two AA batteries.

4. Gas cooking appliance according to claim 1 to 3, wherein the control unit (100) is configured to generate detection voltage signals at a voltage V1 greater than the power supply voltage V, said control unit (100) comprising a multiplexer sequentially sending detection voltage signals and receiving the detection signals to/from the flame sensors (20) to monitor the presence or absence of the flame of the burners (B1-B3).

5. Gas cooking appliance according to any of the preceding claims, wherein the control unit (100) is configured to generate ignition voltage signals at a voltage V2 greater than the power supply voltage V, sending the ignition voltage signals to the electrodes (10) to generate sparks next to the burners (B1-B3).

6. Gas cooking appliance according to any of the preceding claims, comprising a single switch (40) associated with a respective actuator (31), said actuator (31) being preferably a push-button.

7. Gas cooking appliance according to any of claims 1 to 5, comprising a switch (40) associated with each gas valve (30), preferably each gas valve (30) comprising an actuator (31) for regulating the gas flow when it is actuated and associated with the respective switch (40), and more preferably the actuator (31) acting by regulating the gas flow of the gas valve (30) in a first range of actuation, and the switch (40) being activated at any point of a second range of actuation, the second range of actuation being less than or equal to the first range of actuation.

8. Gas cooking appliance according to any of the preceding claims, wherein each electrode (10) and each flame sensor (20) associated with each respective burner (B1-B3) form a single part.

9. Gas cooking appliance according to any of the preceding claims, comprising a bistable gas valve (50) arranged in the gas conduit (32), fluidically communicating a gas supply (33) with the gas valves (30), said bistable gas valve (50) being electrically connected to the control unit (100), and said control unit (100) being configured to open and close the bistable gas valve (50) by sending an electric current pulse, said valve (50) preferably comprising a manual actuator (51) accessible from the outside and configured to arrange the valve (50) in a stable opening position manually.

10. Gas cooking appliance according to any of the preceding claims, comprising illumination means (60) and/or acoustic means (70) which inform the user about the state in which the gas cooking appliance (200) is, preferably when a burner (B1-B3) has been ignited, when a burner (B1-B3) has not been ignited or has been turned off, or when, after closing the gas flow in the gas valves (30), a determined residual heat threshold is exceeded in the gas cooking appliance (200).

11. Method for controlling the presence or absence of flame of a plurality of burners (B1-B3), implemented with a gas cooking appliance (200) comprising:

- the plurality of gas burners (B1-B3) to which gas flow reaches,

- an electrode (10) associated with each burner (B1-B3),

- a flame sensor (20) associated with each burner (B1-B3), the flame sensor (20) being configured to provide a detection signal based on the presence or absence of the flame,

- a gas valve (30) associated with each burner (B1-B3) for regulating the gas flow reaching the corresponding burner (B1-B3) from a gas conduit (32),

- at least one electric switch (40) associated with an actuator (31), and configured to be activated when the actuator (31) is actuated, and

- a control unit (100) electrically connected to the electrodes (10), the flame sensors (20) and the switch (40),

the method comprising:

- an ignition step (S2), when the at least one switch (40) is actuated for igniting at least one burner (B1-B3), for activating the electrodes (10) and the flame sensors (20) associated to at least said at least one burner (B1-B3), and

- a monitoring step (S4) for monitoring the presence or absence of flame ignited in said at least one burner (B1-B3), based on the reception of the detection signals sent by the respective flame sensors (20),

characterized in that in the monitoring step (S4) only those burners (B1-B3) which have been lit during the ignition step (S2) are monitored, said monitorization being carried out sequentially in time cycles T, monitoring the detection signal of each flame sensor (20) one at a time during each of the repeating time cycles T.

12. Method according to claim 11, wherein, during the ignition step (S2), the electrodes (10) and the flame sensors (20) of all the burners (B1-B3) are activated, said activation being carried out so that it is alternated a simultaneous activation of all electrodes (10) with a sequential activation of flame sensors (20), so that each flame sensor (20) is activated one at a time between the activation of the electrodes (10).

13. Method according to claim 11 or 12, wherein the monitoring step (S4) comprises a flame existence verification phase (P41), wherein the decision is made to carry out a waiting phase (P411, P413) of the burner B1-B3 for a determined waiting time (Tr, Te), if the control unit 100 receives a flame absence detection signal from the flame sensor (20).

14. Method according to claim 13, comprising a step of turning off (S5) of the gas cooking appliance (200), said step of turning off (S5) comprising a turning off phase (P51) of the control unit (100) if, after receiving a flame absence detection signal from a flame sensor (20), the waiting time (Tr, Te) has elapsed.

15. Method according to claim 14, wherein the gas cooking appliance (200) comprises a bistable gas valve (50) arranged in the gas conduit (32) fluidically communicating a gas supply (33) with the gas valves (30), said bistable gas valve (50) being electrically connected to the control unit (100), the method comprising a step of opening the passage of gas (S3) comprising an opening phase (P31) wherein the valve (50) is arranged in a stable open position, wherein the step of turning off (S5) of the gas cooking appliance (200) preferably comprises a closing phase (P53) before the turning off phase (P51), wherein the bistable gas valve (50) is arranged in a stable close position.

Drawing