Combustion equipment and cooking appliances

Abstract

To provide a combustion apparatus and a heating cooker capable of preventing the discharge of gas causing uncomfortable feeling and uneasiness to users, even if heating power adjustment control operation is carried out by using a latch type solenoid valve.SOLUTION: A combustion apparatus 1 includes a burner 3, a gas supply path 24 that supplies fuel gas to the burner, a latch type solenoid valve 5 that opens / closes the gas supply path, igniting means 7 and 9 for burning the fuel gas supplied to the burner, and a control portion 6 that instructs the latch type solenoid valve to open and close and instructs the igniting means to ignite the fuel gas. The control portion 6 gives a continuous igniting instruction which repeats igniting instruction to the igniting means 7 and 9 under a predetermined condition after the valve closing instruction of the latch type solenoid valve 5, when performing heating-power regulating control operation which alternately repeats a combustion process in which the latch type solenoid valve 5 is opened by a valve opening instruction to instruct the igniting means 7 and 9 to burn the burner 3 and an extinction process in which the latch type solenoid valve 5 is closed by a valve closing instruction to extinguish the burner 3.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a combustion device and a cooking heater capable of executing a firepower adjustment control operation that alternately repeats a combustion process and an extinguishing process.

Background Art

[0002] For example, Patent Document 1 discloses that in a grill device, a firepower adjustment control operation is performed to temporarily extinguish the combustion of a burner and repeat the combustion process and the extinguishing process to keep the temperature inside the cabinet within a certain range. Here, generally, for the switching between the combustion process and the extinguishing process in the firepower adjustment control operation as described above, an on-off valve that can reliably maintain the open and closed states, such as an electric valve, is used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, a latch-type solenoid valve using a permanent magnet and an electromagnetic coil is known as a means of adjusting the flame output of a burner. In a latch-type solenoid valve, the valve is opened or closed by applying a valve drive voltage to the electromagnetic coil for the required time as an opening or closing instruction, and thereafter the valve state is maintained by the action of a permanent magnet or spring. When we carefully considered a configuration that uses this latch-type solenoid valve to switch between the combustion process and the extinguishing process in the aforementioned flame output control operation, we found that if the latch-type solenoid valve opens during the extinguishing process after the closing instruction of the latch-type solenoid valve due to an abnormality such as a malfunction of the microcontroller or circuit caused by external noise, or if the valve body that opened due to this malfunction becomes stuck and fails to open, gas will continue to be released from the burner. If the gas release state continues for a long time, the gas release will cause a gas odor, and when ignition is performed to start the combustion process again, the stagnant gas will also ignite, causing combustion accompanied by a loud noise, which may cause discomfort and anxiety to the user.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a combustion device and a cooking appliance that can prevent the release of gases that cause discomfort or anxiety to the user, even when operating with a latch-type solenoid valve for flame control. [Means for solving the problem]

[0006] The combustion device of Invention 1 is Burner and, A gas supply path for supplying fuel gas to the burner, A latch-type solenoid valve that opens and closes the gas supply path, An ignition means for burning the fuel gas supplied to the burner, The system includes a control unit that instructs the latch-type solenoid valve to open and close, and instructs the ignition means to ignite the fuel gas, When the control unit performs a flame control operation in which it alternately repeats a combustion process in which it opens the latch-type solenoid valve in response to an open command and issues an ignition command to the ignition means to ignite the burner, and an extinguishing process in which it closes the latch-type solenoid valve in response to a close command to extinguish the burner, the control unit includes a control configuration that issues a continuous ignition command to the ignition means to repeatedly issue an ignition command under predetermined conditions after the latch-type solenoid valve is closed.

[0007] With the above configuration, during the fire extinguishing process, which is executed by a closing instruction of the latch-type solenoid valve in the fire power control operation, a continuous ignition instruction is repeatedly given to the ignition means. As a result, even if the latch-type solenoid valve opens due to some abnormality during the fire extinguishing process, or if the opened latch-type solenoid valve malfunctions and opens further, the continuous ignition instruction allows the ignition means to ignite the gas released from the burner and create a combustion flame. Therefore, it is possible to prevent the release of gas from the burner that may cause discomfort or anxiety to the user, such as a gas odor or combustion accompanied by a loud noise when igniting to restart the combustion process. Thus, when performing fire power control operation that alternates between the combustion process and the fire extinguishing process using a latch-type solenoid valve, it is possible to use the combustion device with peace of mind without the user experiencing discomfort or anxiety due to the release of gas from the burner. The above predetermined conditions can be such as when the conditions for starting the fire extinguishing process are met, or when the start of the fire extinguishing process is confirmed.

[0008] The combustion apparatus of Invention 2 is In the combustion apparatus described in Invention 1 above, The burner has a flame detection means for detecting the combustion flame, The control unit can be configured to issue an ignition command to the ignition means as a continuous ignition command when the flame detection means detects that the burner has been extinguished, as a predetermined condition.

[0009] With the above configuration, the control unit can determine the soundness (normal operation) of the latch-type solenoid valve at that time by confirming the extinguishing of the burner using the flame detection means, and can also recognize the start of the extinguishing process. Therefore, by setting the detection of the extinguishing of the burner by the flame detection means as meeting predetermined conditions, continuous ignition instructions can be reliably given during the extinguishing process. Thus, even if the latch-type solenoid valve opens due to malfunction or other reasons during the extinguishing process, or opens and then malfunctions and opens again, the burner can be ignited by the continuous ignition instruction, preventing the release of gas from the burner that would cause discomfort or anxiety to the user.

[0010] The combustion apparatus of Invention 3 is In the combustion apparatus described in Invention 1 above, It has a temperature sensing means for detecting the temperature of the combustion space and / or the object being heated, The control unit can be configured to issue an ignition command to the ignition means as a continuous ignition command when the temperature detection means detects predetermined temperature information that meets the predetermined conditions.

[0011] Here, the temperature of the combustion space includes the temperatures of various spaces in which the burner is installed. The temperature of the object to be heated includes the temperature of the cooking utensil heated by the burner, the temperature of the food contained in the cooking utensil, etc. The temperature information includes temperature values, temperature gradients, temperature changes, etc. With the above configuration, the control unit can confirm the extinguishing of the burner by detecting predetermined temperature information with the temperature detection means, thereby enabling it to grasp the soundness (normal operation) of the latch-type solenoid valve at that time and to reliably recognize the start of the extinguishing process. Therefore, by defining the detection of predetermined temperature information with the temperature detection means and confirming the extinguishing of the burner as meeting predetermined conditions, it is possible to reliably issue a continuous ignition command during the extinguishing process. Thus, even if the latch-type solenoid valve opens due to malfunction or other reasons during the extinguishing process, or if it opens and then malfunctions and opens again, the burner can be ignited by issuing a continuous ignition command, preventing the release of gas from the burner that would cause discomfort or anxiety to the user.

[0012] The combustion apparatus of Invention 4 is In the combustion apparatus described in any one of the above inventions 1 to 3, The control unit can be configured to issue an ignition command to the ignition means at predetermined intervals as a continuous ignition command.

[0013] With the above configuration, by making the elapsed time shorter than the amount of gas released from the burner that would cause the user to smell gas or produce a loud noise during ignition, continuous ignition instructions can be given at this time cycle. This makes it possible to ignite the gas released from the burner and create a combustion flame if the latch-type solenoid valve malfunctions and opens during the extinguishing process, or if it opens and then opens again, thereby limiting the release of gas from the burner to a level that does not cause discomfort or anxiety to the user.

[0014] The combustion apparatus of Invention 5 is In the combustion apparatus described in any one of the above inventions 1 to 4, The control unit can be configured to interrupt the continuous ignition instruction after an instruction to open the latch-type solenoid valve has been given.

[0015] With the above configuration, since the combustion process is executed after the latch-type solenoid valve is opened, the continuous ignition command is interrupted during the combustion process, thereby preventing unnecessary ignition operations and reducing wear on the ignition means.

[0016] The combustion apparatus of Invention 6 is In the combustion apparatus described in any one of inventions 1 to 5 above, The burner has a flame detection means for detecting the combustion flame, The control unit can be configured to interrupt the continuous ignition instruction if the flame detection means detects the combustion flame of the burner after the latch-type solenoid valve has been opened.

[0017] With the above configuration, when the flame detection means detects the combustion flame of the burner after the valve opening instruction of the latch-type solenoid valve, since the combustion flame is formed in the burner and the combustion process is being executed, when the combustion flame is surely formed in the burner, the continuous ignition instruction is interrupted, so that it is possible to suppress the consumption of the ignition means without performing unnecessary ignition operations.

[0018] The combustion device of Invention 7 is In the combustion device according to any one of the above-mentioned Inventions 1 to 6, flame detection means for detecting the combustion flame of the burner, and abnormality notification means for notifying an abnormality, and the control unit can be configured to notify an abnormality by the abnormality notification means when the flame detection means detects the combustion flame of the burner as a result of the continuous ignition instruction.

[0019] With the above configuration, when the flame detection means detects the combustion flame of the burner as a result of the continuous ignition instruction, it can be determined that the latch-type solenoid valve has opened abnormally during the fire extinguishing process. Therefore, by notifying an abnormality by the abnormality notification means, it is possible to promptly notify the user that the combustion device is not operating normally.

[0020] The combustion device of Invention 8 is In the combustion device according to any one of the above-mentioned Inventions 1 to 7, flame detection means for detecting the combustion flame of the burner, and an electromagnetic safety valve provided in the gas supply passage for shutting off the gas supply passage, and the control unit can be configured to shut off the gas supply passage by the electromagnetic safety valve when the flame detection means detects the combustion flame of the burner as a result of the continuous ignition instruction.

[0021] With the above configuration, if the flame detection means detects a combustion flame from the burner as a result of a continuous ignition command, it can be determined that the latch-type solenoid valve opened due to an abnormality during the extinguishing process. Therefore, by shutting off the gas supply path with the solenoid safety valve, the burner that was ignited by the continuous ignition command can be extinguished, and gas release from the burner can be prevented, making it possible to safely shut down the combustion device.

[0022] The combustion device of Invention 9 is In the combustion apparatus described in any one of the above inventions 1 to 8, The aforementioned burners are provided in multiple quantities. The gas supply path is branched to supply fuel gas to each of the burners. The aforementioned latch-type solenoid valves are provided in each of the branched gas supply passages, Each of the aforementioned burners is equipped with the aforementioned ignition means and a flame detection means for detecting the combustion flame of the burner. The control unit may be equipped with a control configuration capable of issuing continuous ignition instructions to the burners and issuing opening and closing instructions to the latch-type solenoid valves for each burner individually.

[0023] With the above configuration, a predetermined combustion space is formed with all or some of the multiple burners, and when flame control operation is performed using a latch-type solenoid valve in this combustion space, even if the latch-type solenoid valve opens due to malfunction or other reasons during the fire extinguishing process, or if it opens and then opens again due to a malfunction, the gas released from the burner is ignited by the ignition means in response to a continuous ignition instruction, creating a combustion flame. This prevents the release of gas from the burner that would cause discomfort or anxiety to the user.

[0024] The combustion apparatus of Invention 10 is In the combustion apparatus described in any one of the above inventions 1 to 9, The burner has a flame detection means for detecting the combustion flame, The control unit can be configured to issue a second closing instruction to the latch-type solenoid valve if, after issuing a first closing instruction to the latch-type solenoid valve, it repeatedly issues ignition instructions to the ignition means under predetermined conditions, and as a result, the flame detection means detects a combustion flame from the burner.

[0025] With the above configuration, if the latch-type solenoid valve opens due to some abnormality during the fire extinguishing process executed by the first closing instruction of the latch-type solenoid valve, a combustion flame is formed in the burner by the ignition means in the form of a continuous ignition instruction. If the flame detection means detects a combustion flame in the burner as a result of this continuous ignition instruction, a second closing instruction is given to the latch-type solenoid valve. Therefore, if the opening of the latch-type solenoid valve during the fire extinguishing process is due to a temporary abnormality, the latch-type solenoid valve is closed by the second closing instruction, the burner is extinguished, and the fire extinguishing process can be returned to a normal state. The second closing instruction can be given not only once but also retried several times, making it easier to return the latch-type solenoid valve that opened due to a temporary abnormality to a normal closed state through retries.

[0026] The combustion device of Invention 11 is In the combustion apparatus described in invention 10 above, The gas supply path is provided with an electromagnetic safety valve that shuts off the gas supply path, The control unit can be configured to close the electromagnetic safety valve and shut off the gas supply path if the flame detection means detects the combustion flame of the burner even after issuing a second closing instruction to the latch-type solenoid valve, and to continue the heat output adjustment control operation if the flame detection means no longer detects the combustion flame of the burner as a result of issuing a second closing instruction to the latch-type solenoid valve.

[0027] With the above configuration, if the flame detection means detects the burner's combustion flame even after issuing a second closing instruction for the latch-type solenoid valve, it can be determined that the latch-type solenoid valve has malfunctioned and is open. In this case, by closing the electromagnetic safety valve and blocking the gas supply path, it is possible to extinguish the burner that has been burning under the continuous ignition instruction, prevent gas from being released from the burner, and safely stop the combustion device. On the other hand, if the flame detection means no longer detects the burner's combustion flame as a result of issuing a second closing instruction for the latch-type solenoid valve, it can be determined that the latch-type solenoid valve has operated normally and closed. In this case, it is possible to return to the normal fire extinguishing process, and by continuing the heat output control operation, it is possible to improve user convenience. Therefore, when performing heat output control operation using a latch-type solenoid valve, even if the latch-type solenoid valve unexpectedly opens during the fire extinguishing process, it is possible to prevent gas from being released from the burner in a way that would cause discomfort or anxiety to the user, and to improve user convenience.

[0028] The combustion apparatus of Invention 12, A cooking appliance can be provided with a combustion device as described in any one of the above inventions 1 to 11.

[0029] For example, in cooking appliances such as grills and gas stoves, when using a latch-type solenoid valve for flame control operation, even if the latch-type solenoid valve malfunctions and opens during the extinguishing process, or if it opens and then opens again, the continuous ignition instruction allows the ignition means to ignite the gas released from the burner and create a combustion flame, preventing the release of gas from the burner that would cause discomfort or anxiety to the user. [Brief explanation of the drawing]

[0030] [Figure 1] This is a schematic diagram showing the grill device of Embodiment 1. [Figure 2] This is a cross-sectional view showing the open and closed states of a latch-type solenoid valve. [Figure 3] This is a time chart illustrating the operation when a latch-type solenoid valve is used during the combustion process and fire extinguishing process in the firepower control operation of Embodiment 1. [Figure 4] This flowchart shows the operation of the control unit that performs the heat output control operation in the grill device of Embodiment 1. [Figure 5] This flowchart shows the operation of the control unit that performs the heat output control operation in the grill device of Embodiment 2. [Figure 6] This is a flowchart showing the operation of the control unit in the modified example 1. [Figure 7] This is a flowchart showing the operation of the control unit in modified example 2. [Modes for carrying out the invention]

[0031] Embodiments of the present invention will be described below with reference to the accompanying drawings. (Embodiment 1) This first embodiment is a grilling device to which the combustion device according to the present invention is applied, and the grilling device of this first embodiment is incorporated, for example, into the casing of a gas stove (not shown).

[0032] As shown in Figure 1, the grill device 1 of Embodiment 1 is a double-sided grill device and comprises a grill compartment 2 for accommodating food F, an upper burner 3a provided on the ceiling of the grill compartment 2 for heating food F from above, lower burners 3b provided at the lower part of the left and right side walls of the grill compartment 2 for heating food F from below, an upper gas supply passage 4a for supplying fuel gas to the upper burner 3a, a lower gas supply passage 4b ​​for supplying fuel gas to the lower burner 3b, latch-type solenoid valves 5a and 5b provided in the upper and lower gas supply passages 4a and 4b respectively for opening and closing the gas supply passages 4a and 4b, and a control unit 6 for controlling the operation of the grill device 1.

[0033] A grill door 21 is provided at the front opening of the grill compartment 2, and an exhaust port 22 for discharging exhaust gases and the like from inside the grill compartment 2 is formed at the rear end of the grill compartment 2. The food to be cooked F is placed on cooking utensils 23 such as a grill plate or a grilling net, and the cooking utensils 23 are supported by a support frame 24 attached to the grill door 21. In this embodiment 1, a grill plate is used as the cooking utensil 23. The space inside the grill compartment 2 becomes a combustion space heated by the upper and lower burners 3a and 3b. The food to be cooked F and the cooking utensils 23 become objects to be heated by the upper and lower burners 3a and 3b. A temperature sensor (temperature detection means) 26 is provided inside the grill compartment 2 to contact the bottom surface of the cooking utensils 23 and detect the temperature of the cooking utensils 23. The temperature detected by this temperature sensor 26 is used as the cooking temperature to control the heating and cooking operation. Furthermore, the grill compartment 2 may be equipped with an internal temperature sensor as a temperature detection means to detect the temperature inside the grill compartment 2, or only one of the temperature sensor 26 or the internal temperature sensor may be provided.

[0034] The gas supply passages 4a for the upper burner 3a and 4b for the lower burner 3b are branched from the main gas supply passage 4c, and latch-type solenoid valves 5a and 5b are provided in the upper and lower gas supply passages 4a and 4b, respectively. The main gas supply passage 4c is equipped with an electromagnetic safety valve 25, which acts as an on / off valve to shut off this main gas supply passage 4c. The upper and lower burners 3a and 3b are each provided with ignition electrodes 7a and 7b for igniting the burner, and flame detectors (flame detection means) 8a and 8b, which are composed of thermocouples and detect the combustion flame of the burner. In addition to thermocouples, flame rods or the like may be used as the flame detection means. The ignition electrodes 7a and 7b of the upper and lower burners 3a and 3b are connected to an igniter 9, and activating the igniter 9 generates a spark discharge at each ignition electrode 7a and 7b. The igniter 9 and ignition electrodes 7a and 7b constitute an ignition means for burning the fuel gas supplied to the upper and lower burners 3a and 3b.

[0035] The front panel of the gas stove (not shown) is equipped with an operation panel that includes a temperature setting unit 11 for setting the cooking temperature in the grill device 1, a timer setting unit 12 for setting the cooking time, and an ignition / extinguishing switch 13 for igniting and extinguishing the upper and lower burners 3a and 3b. The temperature setting unit 11, timer setting unit 12, and ignition / extinguishing switch 13 are operated by the user. The grill device 1 is also equipped with an abnormality notification means 14 for issuing an abnormality alert. The abnormality notification means 14 can issue an alert by means of, for example, voice, buzzer, or display.

[0036] The control unit 6 is an electronic unit composed of a microcomputer and electronic circuits, and is equipped with various programs, calculation units, memory units, timers, etc., and controls the operation of the grill device 1, including the combustion, ignition, and extinguishing of the upper and lower burners 3a and 3b. Furthermore, the control unit 6 has a control configuration that enables a heat adjustment control operation in which, in the heating and cooking operation, the combustion process in which the upper and lower burners 3a and 3b are ignited and the extinguishing process in which the upper and lower burners 3a and 3b are extinguished to stop combustion is alternately repeated in order to maintain the cooking temperature within a certain range. In the grill device 1 of this embodiment 1, the switching between the combustion process and the extinguishing process is performed by latch-type solenoid valves 5a and 5b, and the control unit 6 controls the operation of the heat adjustment control operation which alternates between the combustion process and the extinguishing process by issuing open and close instructions to the latch-type solenoid valves 5a and 5b.

[0037] Now, let's explain the latch-type solenoid valve 5. As shown in Figure 2, the latch-type solenoid valve 5 comprises a permanent magnet 51, a core member 52 that contacts the permanent magnet 51, a plunger 53 on which a valve body 56 is provided, an electromagnetic coil 54 that moves the plunger 53, and a spring 55 that biases the plunger 53 in the closing direction.

[0038] When opening the latch-type solenoid valve 5, a valve drive voltage (for example, a positive voltage) is applied to the electromagnetic coil 54 for a certain period of time so that a magnetic flux is generated in the forward direction relative to the magnetic flux of the permanent magnet 51. This causes the plunger 53 to move against the biasing force of the spring 55 (from state (a) to (b) in Figure 2), and the valve body 56 separates from the valve opening 57, resulting in an open valve state. Even if the energization of the electromagnetic coil 54 is stopped in this open valve state, the plunger 53 is attracted and held to the permanent magnet 51 via the core member 52, and the open valve state is maintained. On the other hand, when closing the latch-type solenoid valve 5, a valve drive voltage (for example, a negative voltage) is applied to the electromagnetic coil 54 for a certain period of time so that a magnetic flux is generated in the opposite direction relative to the magnetic flux of the permanent magnet 51. This cancels out the magnetic force of the permanent magnet 51, causing the plunger 53 to move due to the biasing force of the spring 55 (from state (b) to (a) in Figure 2), and the valve body 56 closes the valve opening 57, resulting in a closed valve state. Even if the current to the electromagnetic coil 54 is stopped while the valve is closed, the plunger 53 remains detached from the core member 52 due to the biasing force of the spring 55, and the valve is maintained in the closed state.

[0039] Thus, the latch-type solenoid valve 5 opens or closes by applying a valve drive voltage to the electromagnetic coil 54 for the required time, and thereafter the open or closed state is maintained by the permanent magnet 51 or spring 55. Although the latch-type solenoid valve 5 does not have high reliability in maintaining the open or closed state because the energization of the electromagnetic coil 54 is stopped after the valve body 56 moves, it has advantages such as lower power consumption, less heat generation from the electromagnetic coil 54, and relatively low cost compared to non-latch-type solenoid valves that cannot maintain the valve body position unless the electromagnetic coil is continuously energized. Therefore, it is desirable to be able to use the latch-type solenoid valve 5 without problems in switching between the combustion process and the fire extinguishing process in a combustion device powered by dry cell batteries, for example.

[0040] Next, we will explain the operation when using the latch-type solenoid valve 5 during the combustion and fire extinguishing processes. The time chart in Figure 3 shows examples before countermeasures in Figures 3(a) and 3(b), and Embodiment 1 in Figures 3(c) and 3(d). In the following explanation, the combustion process and the extinguishing process will be described assuming that both the upper burner 3a and the lower burner 3b are used for combustion and extinguishing. In the time chart in Figure 3 and the following explanation, the burner 3, gas supply passage 4, latch-type solenoid valve 5, and ignition electrode 7 refer to both the upper and lower sides.

[0041] As shown in Figure 3(a), when starting the combustion process, a valve drive voltage (for example, a positive voltage of +3V) that instructs the latch-type solenoid valve 5 to open is applied for a certain period of time. This causes the latch-type solenoid valve 5 to open, the gas supply passage 4 opens, and fuel gas is supplied to the burner 3. At this time, the igniter 9 is operated for a certain period of time to generate a spark discharge at the ignition electrode 7, causing the burner 3 to ignite and burn, thus executing the combustion process. Next, when temporarily suspending the combustion process and starting the extinguishing process, a valve drive voltage (for example, a negative voltage of -3V) that instructs the latch-type solenoid valve 5 to close is applied for a certain period of time. This causes the latch-type solenoid valve 5 to close, the gas supply passage 4 is shut off, the burner 3 extinguishes, and the extinguishing process is executed. By controlling the opening and closing of the latch-type solenoid valve 5 as described above, it is possible to perform a thermal power control operation that alternately repeats the combustion process and the extinguishing process.

[0042] In the case of using a latch-type solenoid valve 5, as shown in Figure 3(b), if a valve drive voltage (positive voltage) is applied to the latch-type solenoid valve 5 due to malfunction caused by external noise during the fire extinguishing process, causing the latch-type solenoid valve 5 to open, fuel gas will be supplied from the gas supply passage 4 to the burner 3, and gas will continue to be released from the burner 3. If this gas release state continues for a long time during the fire extinguishing process, a gas odor will be generated, and when ignition is started again, the stagnant gas will also ignite, causing combustion accompanied by a loud noise, which may cause discomfort and anxiety to the user. Since the latch-type solenoid valve 5 does not have a means for detecting the position of the valve body and does not output an answer-back signal, the control unit 6 cannot directly recognize if the latch-type solenoid valve 5 opens unexpectedly due to malfunction after a valve closing instruction.

[0043] Therefore, in this embodiment 1, as shown in Figure 3(c), during the fire extinguishing process, an ignition voltage is applied to the igniter 9 at a constant period (every S seconds) (see the blacked-out area in Figure 3(c)), generating a spark discharge at the ignition electrode 7 and repeatedly issuing an ignition command to ignite the burner 3. In other words, the control unit 6 is configured to issue a continuous ignition command, repeatedly issuing an ignition command to the igniter 9 at predetermined time intervals S from the start of the fire extinguishing process. Here, the predetermined time S is set to be shorter than the amount of gas released from the burner 3 that would cause the user to smell gas or result in a loud combustion noise when igniting the next combustion process, during the opening time of the latch-type solenoid valve 5 when the burner 3 is extinguished. This predetermined time S can be determined by experimentation or other means depending on the combustion device such as the grill device 1. Furthermore, as the timing of the ignition instruction at predetermined time intervals S, for example, the predetermined time interval S may be counted periodically based on when the closing instruction is given to the latch-type solenoid valve 5 to start the fire extinguishing process or when the extinguishing of the burner 3 is confirmed. Alternatively, the timing of the first ignition instruction after entering the fire extinguishing process may be counted based on when the closing instruction is given to the latch-type solenoid valve 5 to start the fire extinguishing process or when the extinguishing of the burner 3 is confirmed, and the timing of the second and subsequent ignition instructions may be counted each time based on the previous ignition instruction.

[0044] As shown in Figure 3(d), the continuous ignition instruction allows the gas released from the burner 3 to be ignited and a combustion flame to be formed even if the latch-type solenoid valve 5 opens due to malfunction during the fire extinguishing process, thus preventing the gas from being continuously released from the burner 3. Furthermore, since the control unit 6 interrupts the continuous ignition instruction after issuing an instruction to open the latch-type solenoid valve 5 for the combustion process, unnecessary ignition operations are not performed by the igniter 9 and ignition electrode 7 during the combustion process, thus reducing wear on the igniter 9 and ignition electrode 7. In addition, if the device uses batteries as its power source, battery consumption can be reduced.

[0045] Next, the operation of the heat output control operation by the control unit 6 in the grill device 1 of Embodiment 1 will be explained. Referring to the flowchart in Figure 4, when the user sets the cooking temperature using the temperature setting unit 11 on the control panel, sets the cooking time using the timer setting unit 12, and turns on the ignition / extinguishing switch 13, the control unit 6 ignites the upper and lower burners 3a and 3b and starts the heating and cooking operation (step S1). As the heating and cooking operation begins, the upper and lower burners 3a and 3b are ignited and the combustion process is performed, causing the temperature inside the grill compartment 2 and the temperature of the food F to rise. Then, in step S2, the control unit 6 determines whether the temperature detected by the temperature sensor 26 has risen to or above the extinguishing temperature a. Here, the extinguishing temperature a is, for example, a temperature value several degrees higher than the cooking temperature set in the temperature setting unit 11, but it can be determined by experimentation or other means depending on the grill device 1.

[0046] If, in step S2, the temperature detected by the temperature sensor 26 is determined not to have risen above the fire extinguishing temperature a (if the answer in step S2 is "NO"), the process proceeds to step S12, where the control unit 6 determines whether the operating time for heating has exceeded the cooking time t set in the timer setting unit 12. If the operating time is determined to have exceeded the cooking time t (if the answer in step S12 is "YES"), the control unit 6 issues an termination notification and closes the electromagnetic safety valve 25 (SV) to end the heating operation (step S14). If the operating time is determined not to have exceeded the cooking time t (if the answer in step S12 is "NO"), the process returns to step S2.

[0047] If, in step S2, the control unit 6 determines that the temperature detected by the temperature sensor 26 has risen to or above the extinguishing temperature a (if the answer in step S2 is "YES"), the process proceeds to step S3, in order to start the extinguishing process. In step S3, the control unit 6 issues a valve closing instruction to the latch-type solenoid valves 5a and 5b. This closing instruction applies a valve drive voltage (e.g., a negative voltage) to the latch-type solenoid valves 5a and 5b for a certain period of time (e.g., 0.5 seconds). As a result, the latch-type solenoid valves 5a and 5b are closed, and the upper and lower burners 3a and 3b are extinguished. In the following step S4, the control unit 6 determines whether the detection voltage (TC detection voltage) of the flame detectors 8a and 8b has dropped below the extinguishing detection voltage V1 within a certain period of time after the valve closing instruction to the latch-type solenoid valves 5a and 5b. Here, the extinguishing detection voltage V1 is, for example, the thermocouple voltage value of the flame detectors 8a and 8b when there is no combustion flame in the burner. If the detection voltage of either the upper or lower flame detector 8a,8b does not drop below the fire extinguishing detection voltage V1 (if the answer in step S4 is "NO"), it is determined that the latch-type solenoid valves 5a,5b have malfunctioned and the process proceeds to step S5, where the heating and cooking operation is stopped due to an error. When an error occurs, the control unit 6 issues an error notification using the abnormality notification means 14 and closes the electromagnetic safety valve 25 (the error stop operation described later is basically the same). On the other hand, if the detection voltage of the flame detectors 8a,8b drops below the fire extinguishing detection voltage V1 (if the answer in step S4 is "YES"), it is determined that the upper and lower burners 3a,3b have been extinguished and the fire extinguishing process has started, and the process proceeds to step S6.

[0048] When the fire extinguishing process is executed, the temperature inside the grill compartment 2 and the temperature of the food F decrease. In step S6, the control unit 6 determines whether the temperature detected by the temperature sensor 26 has fallen below the combustion temperature b. Here, the combustion temperature b is set to a temperature value that is several degrees lower than the cooking temperature set by the temperature setting unit 11, for example, but can be determined by experimentation or other means depending on the grill device 1. As long as it is determined in step S6 that the temperature detected by the temperature sensor 26 has not fallen below the combustion temperature b (if "NO" is determined in step S6), the fire extinguishing process continues to be executed, and the process proceeds to step A, where a continuous ignition instruction is given to the upper and lower burners 3a and 3b. The processing operation of the continuous ignition instruction in step A will be described later.

[0049] On the other hand, if in step S6 the temperature detected by the temperature sensor 26 has fallen below the combustion temperature b (if the answer in step S6 is "YES"), the control unit 6 proceeds to step S7 to reignite the upper and lower burners 3a and 3b and perform the combustion process. The control unit 6 issues an open command to the latch-type solenoid valves 5a and 5b. This open command applies a valve drive voltage (for example, a positive voltage) to the latch-type solenoid valves 5a and 5b for a certain period of time (for example, 0.5 seconds) to cause them to open. As a result, the latch-type solenoid valves 5a and 5b open, and fuel gas is supplied to the upper and lower burners 3a and 3b from the gas supply passages 4a and 4b. Subsequently, in step S8, the control unit 6 activates the igniter 9 for a certain period of time in response to an ignition command, generating a spark discharge at the ignition electrodes 7a and 7b. As a result, the upper and lower burners 3a and 3b ignite and begin combustion. In the following step S9, it is determined whether the detection voltage of the flame detectors 8a and 8b has risen to or above the ignition detection voltage V2 within a certain time period following the ignition instruction from the igniter 9 or the opening instruction from the latching solenoid valves 5a and 5b. Here, the ignition detection voltage V2 is, for example, the thermocouple voltage value of the flame detectors 8a and 8b when a combustion flame is formed in the burner. If the detection voltage of the flame detectors 8a and 8b has not risen to or above the ignition detection voltage V2 on either the upper or lower side (if the result in step S9 is "NO"), it is determined that the latching solenoid valves 5a and 5b have closed and malfunctioned, and the process proceeds to step S10, where the heating and cooking operation is stopped due to an error. On the other hand, if the detection voltage of the flame detectors 8a and 8b has risen to or above the ignition detection voltage V2 (if the result in step S9 is "YES"), it is determined that the upper and lower burners 3a and 3b are burning and the combustion process has resumed, and the process proceeds to step S11. When the combustion process is executed again, the temperature inside the grill chamber 2 and the temperature of the food F rise again.

[0050] In step S11, the control unit 6 determines whether the operating time for heating has exceeded the cooking time t set by the timer setting unit 12. If it determines that the operating time has exceeded the cooking time t (if "YES" is answered in step S11), it proceeds to step S14 to terminate the heating operation. If it determines that the operating time has not exceeded the cooking time t (if "NO" is answered in step S11), it returns to step S2. Therefore, the process from step S2 to step S12 is repeated until the operating time for heating has exceeded the cooking time t. In other words, in the heating operation, a heat control operation is performed in which the combustion process and the extinguishing process are repeated alternately.

[0051] Next, we will explain the operation of the continuous ignition instruction in step A. In step A1 of this continuous ignition instruction, the control unit 6 determines whether a predetermined time S has elapsed in the fire extinguishing process cycle due to the start of the fire extinguishing process. Here, the predetermined time S is set to be shorter than the amount of gas released from the upper and lower burners 3a and 3b during the opening time of the latch-type solenoid valves 5a and 5b when the burners are extinguished (for example, 15 seconds).

[0052] If it is determined that the fire extinguishing process time cycle has not elapsed for a predetermined time S (if "NO" is answered in step A1), the process proceeds to step A3. On the other hand, if it is determined that the fire extinguishing process time cycle has elapsed for a predetermined time S (if "YES" is answered in step A1), in step A2, the control unit 6 issues an ignition command to the igniter 9. This ignition command applies an ignition voltage to the igniter 9, causing it to operate for a certain period of time and generate a spark discharge at the ignition electrodes 7a and 7b. As a result, if the latch-type solenoid valves 5a and 5b are normally closed, there is no change in the state of the upper and lower burners 3a and 3b. However, if the latch-type solenoid valves 5a and 5b are abnormally open, the gas released from the upper and lower burners 3a and 3b ignites and burns.

[0053] In the following step A3, the control unit 6 determines whether the detection voltage of the flame detectors 8a and 8b has risen to or above the ignition detection voltage V2 within a certain time period from the ignition command. If the detection voltage of the flame detectors 8a and 8b rises to or above the ignition detection voltage V2 on either the upper or lower burner side (i.e., if the answer in step A3 is "YES"), it is determined that combustion of the upper and lower burners 3a and 3b has been confirmed, and the control unit 6 determines that the latch-type solenoid valves 5a and 5b have opened during the extinguishing process and have malfunctioned, and proceeds to step A4, where it stops the heating and cooking operation due to an error.

[0054] On the other hand, if the detection voltage of the flame detectors 8a and 8b does not rise above the ignition detection voltage V2 (if "NO" is the result in step A3), combustion of the upper and lower burners 3a and 3b is not confirmed, the latch-type solenoid valves 5a and 5b remain closed, and it can be determined that the fire extinguishing process is being executed normally, so the process proceeds to step S13. In step S13, the control unit 6 determines whether the operating time for heating and cooking has elapsed to the cooking time t set in the timer setting unit 12. If it is determined that the operating time has elapsed to the cooking time t (if "YES" is the result in step S13), the process proceeds to step S14 to terminate the heating and cooking operation, and if it is determined that the operating time has not elapsed to the cooking time t (if "NO" is the result in step S13), the process returns to step S6. Therefore, as long as the heating and cooking operation time has not elapsed beyond the cooking time t (if "NO" is answered in step S13), and the temperature detected by the temperature sensor 26 has not fallen below the combustion temperature b (if "NO" is answered in step S6), the fire extinguishing process continues. During this fire extinguishing process, in step A, the control unit 6 executes a continuous ignition command, repeating the ignition command to the igniter 9 every time a predetermined time S has elapsed in the fire extinguishing process cycle.

[0055] As described above, according to this embodiment 1, even if the latch-type solenoid valves 5a and 5b unexpectedly open during the fire extinguishing process due to external noise, malfunction of circuits, or other abnormalities, or if the valve body 56 that opened due to this malfunction becomes stuck or otherwise fails to open, the gas released from the upper and lower burners 3a and 3b can be ignited and a combustion flame can be created by the ignition instruction (step A2) by the continuous ignition instruction. Therefore, it is possible to prevent the release of gas from the upper and lower burners 3a and 3b that may cause discomfort or anxiety to the user, such as gas odor or combustion accompanied by loud noise when igniting to restart the combustion process.

[0056] Furthermore, if combustion flames are formed in the upper and lower burners 3a and 3b due to a continuous ignition instruction, it is determined that the latch-type solenoid valves 5a and 5b have malfunctioned and an abnormality notification is issued by the abnormality notification means 14, causing the heating and cooking operation to stop due to an error (step A4). Therefore, the abnormality notification allows the user to be quickly informed that the grill device 1 is not operating normally because the latch-type solenoid valves 5a and 5b have opened abnormally during the extinguishing process. In addition, the error stop closes the electromagnetic safety valve 25 and shuts off the gas supply passage 4c, thus extinguishing the upper and lower burners 3a and 3b that were burning due to the continuous ignition instruction, and preventing gas from being released from the upper and lower burners 3a and 3b, thus safely stopping the grill device 1. On the other hand, if combustion flames are not formed in the upper and lower burners 3a and 3b due to a continuous ignition instruction, it can be determined that the latch-type solenoid valves 5a and 5b are maintaining a closed state, confirming that the extinguishing process is being executed normally, and allowing the heat output control operation to continue.

[0057] Therefore, according to this embodiment 1, by using latch-type solenoid valves 5a and 5b as a grill device 1 that enables heat output control operation, it is possible to provide a grill device 1 that can be used safely by the user while keeping costs down.

[0058] If the flame detectors 8a and 8b detect that the upper and lower burners 3a and 3b have been shut down after the latch-type solenoid valves 5a and 5b have been shut down to initiate the fire extinguishing process (if the answer is "YES" in step S4), the control unit 6 issues a continuous ignition command, assuming that the predetermined conditions are met. This allows the control unit 6 to ascertain the soundness (normal operation) of the latch-type solenoid valves 5a and 5b at the start of the fire extinguishing process by confirming that the upper and lower burners 3a and 3b have been shut down by the flame detectors 8a and 8b. The control unit 6 can also recognize the start of the fire extinguishing process by confirming that the upper and lower burners 3a and 3b have been shut down. Therefore, the control unit 6 can reliably issue a continuous ignition command during the fire extinguishing process, and even if the latch-type solenoid valves 5a and 5b open due to an abnormality or malfunction and open further during the fire extinguishing process, the gas released from the upper and lower burners 3a and 3b will be treated as a combustion flame, preventing gas release that would cause discomfort or anxiety to the user.

[0059] During the combustion process, continuous ignition is not instructed. Specifically, continuous ignition is interrupted when the temperature detected by the temperature sensor 26 falls below the combustion temperature b (if "YES" is answered in step S6), after the latch-type solenoid valves 5a and 5b are instructed to open (step S7), or after the flame detectors 8a and 8b detect the combustion flames of the upper and lower burners 3a and 3b after the latch-type solenoid valves 5a and 5b are instructed to open (if "YES" is answered in step S9). This prevents unnecessary ignition operations by the igniter 9 and ignition electrodes 7a and 7b during the combustion process, thereby reducing wear on the igniter 9 and ignition electrodes 7a and 7b. Furthermore, if batteries are used to power the grill device 1, battery consumption can be reduced.

[0060] In Embodiment 1, when issuing a continuous ignition command, the command is issued only when the flame detectors 8a and 8b, which meet predetermined conditions, detect extinguishing the flame and the upper and lower burners 3a and 3b are confirmed to be extinguished (when the answer is "YES" in step S4). However, the command may be issued regardless of whether the flame detectors 8a and 8b detect extinguishing the flame. Furthermore, the predetermined conditions for issuing a continuous ignition command are not limited to confirmation of extinguishing the flames of the upper and lower burners 3a and 3b, but may also be when the conditions for starting the extinguishing process are met (for example, when the temperature detected by the temperature sensor 26 becomes equal to or above the extinguishing temperature a, or when the latch-type solenoid valves 5a and 5b are instructed to close in order to perform the extinguishing process), or when the start of the extinguishing process is confirmed (for example, when the temperature sensor 26 detects predetermined temperature information).

[0061] Furthermore, in the grill device 1 of Embodiment 1, the flame detectors 8a and 8b are provided corresponding to the upper burner 3a and the lower burner 3b, respectively, so that the combustion flames of the upper burner 3a and the lower burner 3b can be detected individually. Therefore, when an error stop occurs (steps S5, S10, A4), the abnormality notification means 14 may notify the system of an abnormality by indicating the abnormal latch-type solenoid valves 5a and 5b, which are identified based on the detection voltage of the flame detectors 8a and 8b.

[0062] (Embodiment 2) Embodiment 2 differs from Embodiment 1 in that it issues a valve closing instruction (second valve closing instruction) for the latch-type solenoid valve during the operation of the continuous ignition instruction. The operation of the control unit in Embodiment 2 will be described below according to the flowchart in Figure 5. In Figure 5, steps numbered the same as in Figure 4 will be omitted from explanation as they follow the operation in Embodiment 1.

[0063] Referring to the flowchart in Figure 5, when the first valve closing instruction is given to the latch-type solenoid valves 5a and 5b in step S3 to start the fire extinguishing process, a continuous ignition instruction is given in step A during this fire extinguishing process. In step A, an ignition instruction is given every predetermined time S of the fire extinguishing process to activate the igniter 9, and it is determined whether the detection voltage of the flame detectors 8a and 8b has risen to or above the ignition detection voltage V2 (steps A1 to A3).

[0064] In step A3, if the detection voltage of the flame detectors 8a and 8b does not rise above the ignition detection voltage V2 (if "NO" is the result in step A3), the control unit 6 determines that the latch-type solenoid valves 5a and 5b are closed normally, and proceeds to step S13 to continue the flame power adjustment control operation. On the other hand, if the detection voltage of the flame detectors 8a and 8b rises above the ignition detection voltage V2 on either the upper or lower flame side (if "YES" is the result in step A3), it can be determined that the upper and lower burners 3a and 3b have ignited and the latch-type solenoid valves 5a and 5b were open. In this case, in step B1, the control unit 6 issues a second closing instruction to the latch-type solenoid valves 5a and 5b. The second closing instruction applies a valve drive voltage (for example, a negative voltage) to the latch-type solenoid valves 5a and 5b for a certain period of time to cause them to close. This second valve closing instruction makes it possible to attempt to return to a normal state by closing the latch-type solenoid valves 5a and 5b that have opened due to an abnormality. Since the flame detectors 8a and 8b are provided corresponding to the upper burner 3a and the lower burner 3b respectively, and can individually detect the combustion flames of the upper burner 3a and the lower burner 3b, the second valve closing instruction in step B1 may be given to the latch-type solenoid valves 5a and 5b on the burner 3a and 3b side corresponding to the flame detectors 8a and 8b whose detection voltage has risen to or above the ignition detection voltage V2 as determined in step A3.

[0065] In the following step B2, the control unit 6 determines whether the detection voltage of the flame detectors 8a and 8b has dropped below the valve failure detection voltage V3 within a certain period of time after the second valve closing instruction. The valve failure detection voltage V3 is, for example, the thermocouple voltage value of the flame detectors 8a and 8b when there is no combustion flame in the burner. If the detection voltage of the flame detectors 8a and 8b drops below the valve failure detection voltage V3 (if "YES" is found in step B2), it is confirmed that the upper and lower burners 3a and 3b, which were burned by the continuous ignition instruction, have been extinguished, and it can be determined that the latch-type solenoid valves 5a and 5b have operated normally and closed. As a result, the system returns to the normal fire extinguishing process. Therefore, since the fire extinguishing process can be executed normally, the control unit 6 proceeds to step S13 and continues the fire power adjustment control operation.

[0066] In step B2, if the detection voltage of either the upper or lower flame detector 8a,8b does not drop below the valve failure detection voltage V3 (i.e., the result in step B2 is "NO"), then the extinguishing of the upper and lower burners 3a,3b cannot be confirmed, and it is determined that the latch-type solenoid valves 5a,5b have malfunctioned and, in step A4, the control unit 6 stops the heating and cooking operation due to an error. Note that the valve failure detection voltage V3 determined in step B2 may be the same as the extinguishing detection voltage V1 determined in step S4.

[0067] As described above, according to Embodiment 2, when the flame detectors 8a and 8b detect the combustion flames of the upper and lower burners 3a and 3b as a result of a continuous ignition command, a second closing command is issued to the latch-type solenoid valves 5a and 5b. If the opening of the latch-type solenoid valves 5a and 5b during the fire extinguishing process is a temporary abnormality, the second closing command closes the latch-type solenoid valves 5a and 5b, allowing the fire extinguishing process to return to a normal state. In other words, as a result of issuing the second closing command to the latch-type solenoid valves 5a and 5b, when the flame detectors 8a and 8b no longer detect the combustion flames of the upper and lower burners 3a and 3b that ignited due to the continuous ignition command, it is determined that the latch-type solenoid valves 5a and 5b have closed and the fire extinguishing process has returned to a normal state, and the fire power adjustment control operation is continued, thereby improving user convenience. Therefore, when using latch-type solenoid valves 5a and 5b to control the flame output, even if the latch-type solenoid valves 5a and 5b unexpectedly open during the fire extinguishing process, it is possible to prevent gas release from the upper and lower burners 3a and 3b, which can cause discomfort and anxiety to the user, such as gas odor or loud noises during ignition at the start of the combustion process, and to improve user convenience.

[0068] On the other hand, even if the second closing instruction is given for the latch-type solenoid valves 5a and 5b, if the flame detectors 8a and 8b detect the combustion flames of the upper and lower burners 3a and 3b that have been ignited by the continuous ignition instruction, it is determined that the latch-type solenoid valves 5a and 5b have malfunctioned and the heating and cooking operation is stopped due to an error. In this case, by closing the electromagnetic safety valve 25 and blocking the gas supply passage 24c, the upper and lower burners 3a and 3b that have been ignited by the continuous ignition instruction are extinguished, and gas is prevented from being released from the upper and lower burners 3a and 3b, making it possible to safely stop the grill device 1.

[0069] Therefore, according to Embodiment 2, by using latch-type solenoid valves 5a and 5b as the grill device 1 that enables heat output control operation, it is possible to provide a grill device 1 that can be used safely by the user while keeping costs down.

[0070] In Embodiment 2, the second valve closing instruction is given only once in step B1. However, the second valve closing instruction may be given several times while the combustion flames of the upper and lower burners 3a and 3b are detected (if "NO" is detected in step B2). This makes it easier to return the latch-type solenoid valves 5a and 5b, which have opened due to a temporary malfunction, to a normal closed state.

[0071] Next, I will explain some variations. (1) Variation 1 Modification 1 is a modification in which, in embodiments 1 and 2, the predetermined condition for issuing a continuous ignition command is set to when the temperature detected by the temperature sensor 26 detects a predetermined temperature. In this modification 1, when the temperature detected by the temperature sensor 26 drops to a predetermined temperature upon the start of the fire extinguishing process, the predetermined condition is met and the continuous ignition command process is executed.

[0072] Referring to the flowchart in Figure 6, in Modification 1, after step S3, there is a step (steps S411 to S413) to confirm that the upper and lower burners 3a and 3b have been extinguished based on the temperature detected by the temperature sensor 26. That is, after instructing the latch-type solenoid valves 5a and 5b to close in step S3 to start the extinguishing process, in the following step S411, the control unit 6 determines whether the temperature detected by the temperature sensor 26 has fallen below the extinguishing confirmation temperature c (for example, the extinguishing temperature a-1°C). When the latch-type solenoid valves 5a and 5b are closed in response to the closing instruction and the upper and lower burners 3a and 3b are extinguished, the temperature detected by the temperature sensor 26 decreases. Therefore, if, after the closing instruction for the latch-type solenoid valves 5a and 5b, the temperature detected by the temperature sensor 26 drops below the fire extinguishing confirmation temperature c within a certain time (t1) (for example, 10 seconds), it is determined that the fire extinguishing of the upper and lower burners 3a and 3b has been confirmed, and the process proceeds to step A, where a continuous ignition instruction is given after the processing in step S6. In other words, if the temperature detected by the temperature sensor 26 drops below the fire extinguishing confirmation temperature c within a certain time (t1) after the closing instruction for the latch-type solenoid valves 5a and 5b, it is considered that the predetermined conditions for issuing a continuous ignition instruction have been met.

[0073] On the other hand, if the temperature detected by the temperature sensor 26 does not fall below the fire extinguishing confirmation temperature c (if "NO" is answered in step S411), and the valve failure detection time t1 has elapsed after the closing instruction for the latch-type solenoid valves 5a and 5b (if "YES" is answered in step S412), it is determined that the latch-type solenoid valves 5a and 5b have opened and the heating and cooking operation is stopped due to an error (step S413).

[0074] The decisions in steps S411 and S412 are to confirm that the upper and lower burners 3a and 3b are extinguished, and also to determine whether the latch-type solenoid valves 5a and 5b are open or malfunctioning. In other words, if the latch-type solenoid valves 5a and 5b are open or malfunctioning, even if a closing command is issued in step S3, the latch-type solenoid valves 5a and 5b will not close, and combustion of the upper and lower burners 3a and 3b will continue, so the temperature detected by the temperature sensor 26 will not decrease. If the latch-type solenoid valves 5a and 5b are functioning normally, issuing a closing command in step S3 will close the latch-type solenoid valves 5a and 5b, extinguishing the upper and lower burners 3a and 3b, causing the temperature inside the grill compartment 2 and the temperature of the food F to decrease, and the temperature detected by the temperature sensor 26 will decrease. Therefore, the control unit 6 can confirm that the upper and lower burners 3a and 3b are extinguished based on the temperature detected by the temperature sensor 26, and can ascertain the soundness (normal operation) of the latch-type solenoid valves 5a and 5b at the start of the fire extinguishing process, and can also recognize the start of the fire extinguishing process. Thus, even if the latch-type solenoid valves 5a and 5b open due to malfunction or other reasons during the fire extinguishing process, or if they open and then fail to open further, the control unit 6 can prevent the gas from continuing to be released from the upper and lower burners 3a and 3b by issuing a continuous ignition instruction to burn the upper and lower burners 3a and 3b.

[0075] In the above-described modified example 1, the fire extinguishing confirmation temperature c in step S411 was set to a temperature value lower than the fire extinguishing temperature a. However, in the determination in step S411, it is determined whether or not the temperature detected by the temperature sensor 26 is less than the fire extinguishing confirmation temperature c. Therefore, the fire extinguishing confirmation temperature c, which is the determination value for the temperature information, may be the same temperature value as the fire extinguishing temperature a.

[0076] (2) Modification example 2 Modification 2 is a variation in which, in embodiments 1 and 2, the predetermined condition for issuing a continuous ignition command is set to when the temperature detected by the temperature sensor 26 detects predetermined temperature information. In this modification 2, when a predetermined temperature decrease gradient is confirmed at the temperature detected by the temperature sensor 26 upon the start of the fire extinguishing process, the predetermined condition is met and the continuous ignition command process is executed.

[0077] Referring to the flowchart in Figure 7, in Modification 2, after step S3, there is a step (steps S421 to S423) to confirm that the upper and lower burners 3a and 3b are extinguished based on the temperature detected by the temperature sensor 26. That is, after step S3, the control unit 6 instructs the latch-type solenoid valves 5a and 5b to close in order to start the extinguishing process, and if the answer in step S421 is "NO", in step S422 the temperature detected by the temperature sensor 26 has not exceeded a predetermined temperature rise ΔT (for example, extinguishing temperature a + 5℃) before the valve failure detection time t2 (for example, 10 seconds) has elapsed. When the latch-type solenoid valves 5a and 5b are closed in accordance with the closing instruction and the upper and lower burners 3a and 3b are extinguished, the temperature detected by the temperature sensor 26 shows a temperature decrease gradient. Therefore, if the temperature detected by the temperature sensor 26 does not exceed the temperature rise ΔT and the valve failure detection time t2 has elapsed (if "NO" is detected in step S422 and "YES" in step S421), it is determined that the extinguishing of the upper and lower burners 3a and 3b has been confirmed, and the process proceeds to step A, which issues a continuous ignition instruction after processing in step S6. In other words, even if a certain period of time (t2) has elapsed after the closing instruction of the latch-type solenoid valves 5a and 5b, if no temperature rise is observed in the temperature detected by the temperature sensor 26 (showing a temperature decrease trend), it is considered that the predetermined conditions for issuing a continuous ignition instruction have been met.

[0078] On the other hand, if, after the closing instruction for the latch-type solenoid valves 5a and 5b, a temperature rise gradient exceeding the temperature rise ΔT is detected at the temperature detected by the temperature sensor 26 before the valve failure detection time t2 has elapsed (if the answer is "YES" in step S422), it is determined that the latch-type solenoid valves 5a and 5b have opened and the heating and cooking operation is stopped due to an error (step S423).

[0079] The decisions in steps S421 and S422 are to confirm that the upper and lower burners 3a and 3b are extinguished, and also to determine whether the latch-type solenoid valves 5a and 5b are open or malfunctioning. In other words, if the latch-type solenoid valves 5a and 5b are open or malfunctioning, even if a closing command is issued in step S3, the latch-type solenoid valves 5a and 5b will not close, and combustion of the upper and lower burners 3a and 3b will continue, causing the temperature detected by the temperature sensor 26 to continue to rise. If the latch-type solenoid valves 5a and 5b are functioning normally, issuing a closing command in step S3 will close the latch-type solenoid valves 5a and 5b, extinguishing the upper and lower burners 3a and 3b, lowering the temperature inside the grill compartment 2 and the temperature of the food F, and causing the temperature detected by the temperature sensor 26 to decrease. Therefore, the control unit 6 can confirm that the upper and lower burners 3a and 3b are extinguished based on the temperature detected by the temperature sensor 26, and can ascertain the soundness (normal operation) of the latch-type solenoid valves 5a and 5b at the start of the fire extinguishing process, and can also recognize the start of the fire extinguishing process. Thus, even if the latch-type solenoid valves 5a and 5b open due to malfunction or other reasons during the fire extinguishing process, or if they open and then fail to open further, the control unit 6 can prevent the gas from continuing to be released from the upper and lower burners 3a and 3b by issuing a continuous ignition instruction to burn the upper and lower burners 3a and 3b.

[0080] In the above-described modified example 2, the temperature rise ΔT was used as the decision value in step S422, but the temperature gradient of the temperature decrease may also be used as the decision value, or any temperature information including temperature gradients or temperature changes may also be used as the decision value.

[0081] Furthermore, the present invention is not limited to the embodiments and modifications described above, and various modifications can be made within the scope of the claims.

[0082] For example, in Embodiments 1 and 2, latch-type solenoid valves 5a and 5b are provided in the upper and lower gas supply passages 4a and 4b, respectively. However, a single latch-type solenoid valve 5 may be provided in the upstream main gas supply passage 4c, and the system may be configured to give instructions to open and close this latch-type solenoid valve 5. In other words, the combustion device of the present invention is equipped with multiple burners, and the gas supply passages are branched to supply fuel gas to each burner. In a configuration where a latch-type solenoid valve is located upstream of this branching point in the gas supply passage, the system may be configured to give instructions to open and close this latch-type solenoid valve.

[0083] In embodiments 1 and 2, the combustion process involves burning both the upper burner 3a and the lower burner 3b. However, for all or part of the combustion process (including all or part of a single combustion process), only the upper burner 3a or the lower burner 3b may be burned.

[0084] In embodiments 1 and 2, one igniter 9 is provided, and the control unit 6 causes all ignition electrodes 7a and 7b to discharge sparks simultaneously by issuing an ignition command to the igniter 9. However, in a configuration where each ignition electrode 7a and 7b is equipped with its own igniter 9, causing each ignition electrode 7a and 7b to discharge sparks individually, the control unit 6 may apply an ignition voltage to each igniter 9 individually and issue ignition commands, including continuous ignition commands, to each burner 3a and 3b individually.

[0085] The present invention may also be applied to a single-sided grilling device that has either an upper burner or a lower burner.

[0086] Furthermore, the present invention may be applied to a gas stove. In this case, the gas stove is equipped with multiple stove burners, the gas supply path is branched to supply fuel gas to each stove burner, each branched gas supply path has a latch-type solenoid valve corresponding to each stove burner, each stove burner is equipped with an ignition electrode and a flame detector, and the control unit can be configured to issue continuous ignition instructions to the stove burners and to issue opening and closing instructions to the latch-type solenoid valves for each stove burner individually. That is, a predetermined combustion space is formed with all or some of the multiple stove burners, and the control unit can perform a heat output control operation that alternately repeats the combustion process and the extinguishing process in the combustion space, and the continuous ignition instructions can be issued in this heat output control operation. Furthermore, in the case of a stove burner that forms a parent-child burner (such as one in which several burner sections that form flame holes are stacked, or one in which burner sections that form flame holes are arranged in a ring shape both inside and outside), the control unit can be configured to issue continuous ignition instructions to the parent-child burner, and to issue opening and closing instructions for each individual burner section of the parent-child burner. [Explanation of Symbols]

[0087] 1. Grilling device (combustion device) 2 Grill compartment 3a Top burner 3b Lower burner 4a, 4b, 4c Gas supply lines 5a, 5b Latch-type solenoid valve 6 Control Unit 7a,7b Ignition electrode (ignition means) 8a, 8b Flame detector (flame detection means) 9. Igniter (ignition method) 11 Temperature setting section 12 Timer setting section 13-point fire extinguishing switch 14 Anomaly notification means 21 Grill Door 22 Exhaust vents 23 Cooking Utensils 24 Support Slots 25 Solenoid safety valve 26 Temperature sensor (temperature detection means) 51 Permanent Magnets 52 Core members 53 Plunger 54 Electromagnetic coil 55 Springs 56 Valve body 57 valve opening F Cooked food

Claims

1. Burner and, A gas supply path for supplying fuel gas to the burner, A latch-type solenoid valve that opens and closes the gas supply path, An ignition means for burning the fuel gas supplied to the burner, The system includes a control unit that instructs the latch-type solenoid valve to open and close, and instructs the ignition means to ignite the fuel gas, The combustion apparatus includes a control configuration that, when the control unit performs a flame control operation in which a combustion process is performed by opening the latch-type solenoid valve in response to an open command and issuing an ignition command to the ignition means to ignite the burner, and an extinguishing process is performed by closing the latch-type solenoid valve in response to a close command to extinguish the burner, the control unit provides a control configuration that repeatedly issues continuous ignition commands to the ignition means during the extinguishing process.

2. In the combustion apparatus according to claim 1, The burner has a flame detection means for detecting the combustion flame, The control unit, when the flame detection means detects that the burner has been extinguished at the start of the fire extinguishing process, executes the process of issuing an ignition instruction to the ignition means as a continuous ignition instruction, in the combustion apparatus.

3. In the combustion apparatus according to claim 1, It has a temperature sensing means for detecting the temperature of the combustion space and / or the object being heated, The control unit performs the step of issuing an ignition instruction to the ignition means as a continuous ignition instruction when the temperature detection means detects predetermined temperature information and the fire extinguishing process is continuing, in a combustion apparatus.

4. In the combustion apparatus according to any one of claims 1 to 3, The control unit issues an ignition command to the ignition means at predetermined intervals as a continuous ignition command, in a combustion device.

5. In the combustion apparatus according to any one of claims 1 to 3, The control unit interrupts the continuous ignition instruction after issuing an opening instruction for the latch-type solenoid valve, in this combustion device.

6. In the combustion apparatus according to any one of claims 1 to 3, The burner has a flame detection means for detecting the combustion flame, The control unit interrupts the continuous ignition instruction when the flame detection means detects a combustion flame from the burner after the latch-type solenoid valve has been opened.

7. In the combustion apparatus according to any one of claims 1 to 3, A flame detection means for detecting the combustion flame of the burner, It has an abnormality notification means for notifying abnormalities, The control unit, as a result of the continuous ignition instruction, detects a combustion flame of the burner using the flame detection means, and the abnormality notification means issues an abnormality notification to the combustion device.

8. In the combustion apparatus according to any one of claims 1 to 3, A flame detection means for detecting the combustion flame of the burner, The gas supply path is provided with an electromagnetic safety valve that shuts off the gas supply path, The control unit, as a result of the continuous ignition instruction, shuts off the gas supply path with the electromagnetic safety valve when the flame detection means detects a combustion flame of the burner.

9. In the combustion apparatus according to any one of claims 1 to 3, The aforementioned burners are provided in multiple quantities. The gas supply path is branched to supply fuel gas to each of the burners. The aforementioned latch-type solenoid valves are provided in each of the branched gas supply passages, Each of the aforementioned burners is equipped with the aforementioned ignition means and a flame detection means for detecting the combustion flame of the burner. The combustion apparatus comprises a control configuration in which the control unit is capable of issuing continuous ignition instructions to the burners and issuing opening and closing instructions to the latch-type solenoid valves for each burner individually.

10. In the combustion apparatus according to any one of claims 1 to 3, The burner has a flame detection means for detecting the combustion flame, Combustion apparatus, wherein the control unit issues a continuous ignition command to the ignition means, repeating the ignition command after the first closing command to the latch-type solenoid valve, and as a result, when the flame detection means detects a combustion flame of the burner, it issues a second closing command to the latch-type solenoid valve.

11. A burner and, A gas supply path for supplying fuel gas to the burner, A latch-type solenoid valve that opens and closes the gas supply path, An ignition means for burning the fuel gas supplied to the burner, The system includes a control unit that instructs the latch-type solenoid valve to open and close, and instructs the ignition means to ignite the fuel gas, When the control unit performs a flame control operation that alternately repeats a combustion process in which the latch-type solenoid valve is opened by an open command and the ignition means is instructed to ignite to ignite the burner, and an extinguishing process in which the latch-type solenoid valve is closed by a close command to extinguish the burner, the control unit is provided with a control configuration that, after the latch-type solenoid valve is closed, repeatedly issues a continuous ignition command to the ignition means under predetermined conditions, thereby repeating the ignition command. The burner has a flame detection means for detecting the combustion flame, If the control unit issues a continuous ignition command to the ignition means, repeating the ignition command under predetermined conditions after the first closing command of the latch-type solenoid valve, and the flame detection means detects a combustion flame of the burner, then the control unit issues a second closing command to the latch-type solenoid valve. The gas supply path is provided with an electromagnetic safety valve that shuts off the gas supply path, Combustion device wherein, even if the control unit issues the second closing instruction to the latch-type solenoid valve, if the flame detection means detects the combustion flame of the burner, it closes the electromagnetic safety valve to shut off the gas supply path, and if, as a result of issuing the second closing instruction to the latch-type solenoid valve, the flame detection means no longer detects the combustion flame of the burner, it continues the heat output adjustment control operation.

12. A cooking appliance comprising a combustion device according to any one of claims 1 to 3.

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