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 is equipped with a burner 3, a gas supply path 4 that supplies fuel gas to the burner 3, a latch type solenoid valve 5 that opens / closes the gas supply path 4, and a control portion 6 that instructs valve-opening or valve-closing of the latch type solenoid valve 5. The control portion 6 gives a continuous valve-closing instruction which instructs the latch type solenoid valve 5 to close valve repeatedly 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 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 combustion 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 combustion 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 combustion 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] By the way, a latching solenoid valve that uses a permanent magnet and an electromagnetic coil is known as a means for adjusting the burner flame. In a latching solenoid valve, a valve drive voltage to the electromagnetic coil is applied for a required time as an open valve instruction or a closed valve instruction to open or close the valve, and then the valve state is maintained by the action of a permanent magnet or a spring. When carefully considering a configuration for switching between the combustion process and the extinguishing process in the combustion control operation using this latching solenoid valve, if the latching solenoid valve opens due to an abnormality such as a malfunction of the microcomputer or circuit caused by external noise or the like during the extinguishing process after the closed valve instruction of the latching solenoid valve, gas will continue to be released from the burner. If the gas release state continues for a long time, there is a risk of a combustion accompanied by a large sound due to the ignition of the stagnant gas at the time of ignition when starting the combustion process again, which may cause discomfort and uneasiness 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, The system includes a control unit that instructs the opening or closing of the latch-type solenoid valve, 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 valve instruction to ignite the burner, and a fire extinguishing process in which it closes the latch-type solenoid valve in response to a close valve instruction to extinguish the burner, the control unit includes a control configuration that performs a continuous closing instruction to the latch-type solenoid valve under predetermined conditions, after the closing instruction to the latch-type solenoid valve.

[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 closing instruction is issued to the latch-type solenoid valve in addition to the closing instruction. As a result, even if the latch-type solenoid valve opens due to some abnormality during the fire extinguishing process, the latch-type solenoid valve can be closed and the gas supply path shut off by a second closing instruction due to the continuous closing instruction. Therefore, it is possible to stop the release of gas from the burner that may cause discomfort or anxiety to the user, such as gas odor or combustion accompanied by loud noise when ignition is started again. 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 gas release 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 a valve-closing instruction to the latch-type solenoid valve as a continuous valve-closing instruction when the flame detection means, which meets the predetermined conditions, detects that the burner has been extinguished.

[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. Therefore, the latch-type solenoid valve can be properly closed by a valve-closing instruction from the control unit. In addition, the start of the fire extinguishing process can be recognized by confirming the extinguishing of the burner. Therefore, by setting the detection of the extinguishing of the burner by the flame detection means as meeting predetermined conditions, continuous valve-closing instructions can be reliably given during the fire extinguishing process. Thus, even if the latch-type solenoid valve opens due to malfunction or other reasons during the fire extinguishing process, the latch-type solenoid valve can be closed by continuous valve-closing instructions, stopping the release of gas from the burner that would cause discomfort or anxiety to the user.

[0010] The combustion device 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 a valve-closing instruction to the latch-type solenoid valve as a continuous valve-closing instruction when the temperature detection means detects predetermined temperature information under 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 that the burner has been extinguished by detecting predetermined temperature information with the temperature detection means, and thus can grasp the soundness (normal operation) of the latch-type solenoid valve at that time. Therefore, the latch-type solenoid valve can be properly closed by a valve-closing instruction from the control unit. In addition, the start of the fire extinguishing process can be recognized by confirming that the burner has been extinguished by detecting predetermined temperature information with the temperature detection means, and thus a predetermined condition is met, making it possible to reliably issue continuous valve-closing instructions during the fire extinguishing process. Therefore, even if the latch-type solenoid valve opens due to malfunction or other reasons during the fire extinguishing process, the latch-type solenoid valve can be closed by the continuous valve-closing instruction, stopping 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 a valve-closing instruction to the latch-type solenoid valve at predetermined intervals as the continuous valve-closing instruction.

[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 for combustion to produce a loud noise upon ignition, and by issuing continuous valve closing instructions at this cycle time, even if the latch-type solenoid valve opens due to malfunction during the fire extinguishing process, the latch-type solenoid valve can be closed to shut off the gas supply path, 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 valve closing instruction after an opening instruction has been given for the latch-type solenoid valve.

[0015] With the above configuration, since the combustion process is executed after the valve opening instruction of the latch-type solenoid valve, during the combustion process, by interrupting the continuous valve closing instruction, it becomes possible to perform a normal combustion process without the latch-type solenoid valve being closed and the burner being extinguished during the combustion process.

[0016] The combustion device of Invention 6 is In the combustion device according to any one of the above-mentioned Inventions 1 to 5, A plurality of the burners are provided, The gas supply passage is branched so as to supply fuel gas to each of the burners, The latch-type solenoid valve is provided in each of the branched gas supply passages, The control unit can be configured to be capable of performing a valve opening instruction, a valve closing instruction, and a continuous valve closing instruction of the latch-type solenoid valve for each of the burners individually.

[0017] With the above configuration, when forming a predetermined combustion space with all or part of a plurality of burners and performing a fire power adjustment control operation using a latch-type solenoid valve in this combustion space, even if the latch-type solenoid valve opens due to a malfunction or the like during the extinguishing process, by shutting off the gas supply passage by the continuous valve closing instruction, it is possible to stop the gas release from the burner that causes the user to feel discomfort or uneasiness.

[0018] The combustion device of Invention 7 can be A cooking heater including the combustion device according to any one of the above-mentioned Inventions 1 to 6.

[0019] For example, in a cooking heater such as a grill device or a gas stove, when performing a fire power adjustment control operation using a latch-type solenoid valve, even if the latch-type solenoid valve opens due to a malfunction or the like during the extinguishing process, by shutting off the gas supply passage by the continuous valve closing instruction, it is possible to stop the gas release from the burner that causes the user to feel discomfort or uneasiness.

Brief Description of the Drawings

[0020] [Figure 1]This is a schematic diagram showing a grill device according to an embodiment. [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 of a latch-type solenoid valve when performing the combustion and extinguishing processes in a thermal power control operation. [Figure 4] This flowchart shows the operation of the control unit that performs the heat output control operation in the grill device of the embodiment. [Figure 5] This flowchart shows the operation of the control unit that performs the heat output control operation in a grill device of another embodiment. [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]

[0021] Embodiments of the present invention will be described below with reference to the accompanying drawings. This embodiment is a grilling device to which the combustion device according to the present invention is applied, and the grilling device of this embodiment is incorporated, for example, into the casing of a gas stove (not shown).

[0022] As shown in Figure 1, the grill device 1 of this embodiment is a double-sided grill device and comprises a grill chamber 2 for accommodating food F, an upper burner 3a provided on the ceiling of the grill chamber 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 chamber 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.

[0023] A grill door 21 is provided at the front opening of the grill compartment 2, and an exhaust port 22 for discharging exhaust gases, etc., 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, 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 cooking operation. Note that an internal temperature sensor for detecting the temperature inside the grill compartment 2 may also be provided as a temperature detection means inside the grill compartment 2, or only one of the temperature sensor 26 or the internal temperature sensor may be provided.

[0024] 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.

[0025] 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.

[0026] 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, 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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 embodiments 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.

[0031] 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.

[0032] 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.

[0033] Therefore, in this embodiment, as shown in Figure 3(c), during the fire extinguishing process, a valve drive voltage (for example, a negative voltage of -3V: see the blacked-out area in Figure 3(c)) is applied to the latch-type solenoid valve 5 as a valve-closing instruction at regular intervals (every S seconds). In other words, the control unit 6 is configured to perform a continuous valve-closing instruction to the latch-type solenoid valve 5 every predetermined time 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 open time of the latch-type solenoid valve 5 when the burner 3 is in the extinguishing state. 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 valve closing instructions by continuous valve closing instructions at predetermined time intervals S, for example, the predetermined time interval S may be counted periodically based on when a valve 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 valve closing instruction by continuous valve closing instructions after entering the fire extinguishing process may be counted based on when a valve 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 valve closing instructions may be counted each time based on the previous valve closing instruction.

[0034] As shown in Figure 3(d), the continuous valve closing instruction allows the latch-type solenoid valve 5 to open due to malfunction or other reasons during the fire extinguishing process. By quickly closing the latch-type solenoid valve 5 and shutting off the gas supply passage 4, the gas release from the burner 3 can be prevented. Furthermore, after the control unit 6 issues an instruction to open the latch-type solenoid valve 5 in order to perform the combustion process following the fire extinguishing process, it suspends the continuous valve closing instruction. As a result, the latch-type solenoid valve 5 is not closed during the combustion process and remains open, allowing for a normal combustion process.

[0035] Next, the operation of the heat output control operation by the control unit 6 in the grill device 1 of this embodiment 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.

[0036] 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.

[0037] 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.

[0038] 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 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 valve closing instruction is given to the latch-type solenoid valves 5a and 5b. The processing operation of the continuous valve closing instruction in step A will be described later.

[0039] 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.

[0040] 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.

[0041] Next, we will explain the operation of the continuous valve closing instruction in step A. In step A1, 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 open time of the latch-type solenoid valves 5a and 5b when the burners are extinguished (for example, 15 seconds).

[0042] If the control unit 6 determines that the fire extinguishing process time cycle has elapsed for a predetermined time S (if the answer is "YES" in step A1), in the following step A2, the control unit 6 issues a valve-closing instruction to the latch-type solenoid valves 5a and 5b. This valve-closing instruction causes a valve drive voltage (for example, a negative voltage) to be applied to the latch-type solenoid valves 5a and 5b for a certain period of time to close. With this second valve-closing instruction, if the latch-type solenoid valves 5a and 5b were closed normally, the closed state is maintained; if the latch-type solenoid valves 5a and 5b were open due to an abnormality, they are closed.

[0043] On the other hand, if the cycle of the fire extinguishing process has not elapsed to a predetermined time S (if "NO" is answered in step A1) or after the valve closing instruction in step A2, 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 answered in step S13), the process proceeds to step S14 to terminate the heating and cooking operation. If it is determined that the operating time has not elapsed to the cooking time t (if "NO" is answered 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 valve closing instruction, repeatedly instructing the latch-type solenoid valves 5a and 5b to close each time a predetermined time S has elapsed in the fire extinguishing process cycle.

[0044] As described above, according to this embodiment, 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, causing gas to be released from the upper and lower burners 3a and 3b, the latch-type solenoid valves 5a and 5b are quickly closed by a subsequent closing instruction (step A2) via a continuous closing instruction, thereby preventing prolonged gas release from the upper and lower burners 3a and 3b. Consequently, it is possible to prevent gas release from the upper and lower burners 3a and 3b that may cause discomfort or anxiety to the user, such as gas odor or loud combustion noise when igniting to restart the combustion process. Therefore, by using latch-type solenoid valves 5a and 5b as a grill device 1 that enables firepower control operation, it is possible to provide a grill device 1 that users can use with peace of mind while keeping costs down.

[0045] Furthermore, if the flame detectors 8a and 8b detect fire extinguishing after the latch-type solenoid valves 5a and 5b have been instructed to close in order to start the fire extinguishing process, a continuous closing instruction will be issued (if "YES" is given in step S4 and "NO" in step S6). In other words, if the flame detectors 8a and 8b detect fire extinguishing of the upper and lower burners 3a and 3b at the start of the fire extinguishing process, a continuous closing instruction will be issued, as the predetermined conditions will be met. As a result, the control unit 6 can ascertain the soundness (normal operation) of the latch-type solenoid valves 5a and 5b at the start of the fire extinguishing process by confirming the extinguishing of the upper and lower burners 3a and 3b by the flame detectors 8a and 8b, and can also confirm the start of the fire extinguishing process. Therefore, since the latch-type solenoid valves 5a and 5b can be properly closed by a valve-closing instruction from the control unit 6, even if the latch-type solenoid valves 5a and 5b open due to malfunction or other reasons during the fire extinguishing process, the latch-type solenoid valves 5a and 5b can be closed by a continuous valve-closing instruction, thereby blocking the gas supply passages 24a and 24b and preventing the gas from continuing to be released from the upper and lower burners 3a and 3b.

[0046] During the combustion process, continuous valve closing instructions are not issued. Specifically, continuous valve closing instructions are 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 opened (step S7), or after the flame detectors 8a and 8b detect combustion flames from the upper and lower burners 3a and 3b after the latch-type solenoid valves 5a and 5b are opened (if "YES" is answered in step S9). As a result, the latch-type solenoid valves 5a and 5b remain open during the combustion process without being closed by continuous valve closing instructions, allowing for a normal combustion process.

[0047] In this embodiment, the continuous valve closing instruction is performed when the flame detectors 8a and 8b, which meet predetermined conditions, detect extinguishing the flame and confirm that the upper and lower burners 3a and 3b are extinguished (when "YES" is answered in step S4). However, the continuous valve closing instruction may be performed regardless of whether the flame detectors 8a and 8b detect extinguishing the flame. Furthermore, the predetermined conditions for performing the continuous valve closing instruction during the fire extinguishing process are not limited to the confirmation of extinguishing the upper and lower burners 3a and 3b being extinguished, but may also be when the conditions for starting the fire extinguishing process are met (for example, when the temperature detected by the temperature sensor 26 becomes equal to or above the fire extinguishing temperature a, or when the latch-type solenoid valves 5a and 5b are instructed to close in order to perform the fire extinguishing process), or when the start of the fire extinguishing process is confirmed (for example, when the temperature sensor 26 detects predetermined temperature information).

[0048] (Other embodiments) Next, other embodiments will be described. Another embodiment differs from the above embodiment in that it repeatedly issues an ignition command at predetermined time intervals S during the fire extinguishing process. The operation of the control unit 6 in the other embodiment 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 the above embodiment.

[0049] Referring to the flowchart in Figure 5, the fire extinguishing process begins in step S3 when the latch-type solenoid valves 5a and 5b are given a first valve closing instruction. When the process proceeds to step A, the control unit 6 determines in step A1 whether the fire extinguishing process time cycle has elapsed for a predetermined time S. The first valve closing instruction is an instruction to apply a valve drive voltage (for example, a negative voltage) that causes the latch-type solenoid valves 5a and 5b to close for a certain period of time. If it is determined that the fire extinguishing process time cycle has not elapsed for the predetermined time S (if "NO" is the result in step A1), the process proceeds to step B2. If it is determined that the fire extinguishing process time cycle has elapsed for the predetermined time S (if "YES" is the result in step A1), the process proceeds to step B1, and the igniter 9 is activated for a certain period of time. When the igniter 9 is activated, a spark discharge occurs at the ignition electrodes 7a and 7b. If the latch-type solenoid valves 5a and 5b are open due to malfunction or other reasons during the fire extinguishing process, the gas released from the upper and lower burners 3a and 3b will ignite and a combustion flame will be formed.

[0050] In the following step B2, 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. Based on this determination in step B2, the control unit 6 confirms whether the latch-type solenoid valves 5a and 5b opened during the fire extinguishing process by detecting whether or not the upper and lower burners 3a and 3b are burning. 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 side (if the answer in step B2 is "YES"), it can be determined that the upper and lower burners 3a and 3b have ignited and the latch-type solenoid valves 5a and 5b have opened. In this case, the process proceeds to step A2, where the control unit 6 issues a second closing instruction to the latch-type solenoid valves 5a and 5b, which is a continuous closing instruction. 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 A2 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 B2.

[0051] On the other hand, if the detection voltage of the flame detectors 8a and 8b does not rise to or above the ignition detection voltage V2 in step B2 (i.e., "NO" in step B2), it can be determined that the latch-type solenoid valves 5a and 5b are closed normally. In this case, the control unit 6 does not issue a closing instruction (second closing instruction) for the latch-type solenoid valves 5a and 5b, and proceeds to step S13 to continue the flame power adjustment control operation.

[0052] If a second valve closing instruction is given to the latch-type solenoid valves 5a and 5b in step A2, in the following step B3, 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 B3), it is confirmed that the upper and lower burners 3a and 3b, which were ignited during the ignition instruction (step B1) in the fire extinguishing process, 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 fire extinguishing process returns to a normal state. 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.

[0053] In step B3, 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 B3 is "NO"), then the control unit 6 determines that the latch-type solenoid valves 5a,5b are open and malfunctioning, and in step B4, it stops the heating and cooking operation due to an error. Note that the valve failure detection voltage V3 determined in step B3 may be the same as the fire extinguishing detection voltage V1 determined in step S4.

[0054] As described above, according to other embodiments, if the flame detectors 8a and 8b detect the combustion flames of the upper and lower burners 3a and 3b as a result of issuing an ignition command during the fire extinguishing process, a second closing command is issued to the latch-type solenoid valves 5a and 5b as a continuous valve closing command. This means that if the opening of the latch-type solenoid valves 5a and 5b during the fire extinguishing process is only 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, if the flame detectors 8a and 8b no longer detect the combustion flames of the upper and lower burners 3a and 3b that ignited during the fire extinguishing process as a result of issuing the second closing command to the latch-type solenoid valves 5a and 5b, the system determines that the latch-type solenoid valves 5a and 5b have closed and the fire extinguishing process has returned to a normal state, and continues the fire power adjustment control operation, 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.

[0055] On the other hand, even if a second closing instruction is given for the latch-type solenoid valves 5a and 5b as a continuous valve closing instruction, 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 ignition instruction during the fire extinguishing process, 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 ignition instruction during the fire extinguishing process 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.

[0056] Therefore, according to other embodiments, 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.

[0057] In other embodiments, the second valve closing instruction is given only once in step A2, but 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.

[0058] In other embodiments, the second valve closing instruction (step A2), which is a continuous valve closing instruction, is an instruction to apply a valve drive voltage to the latch-type solenoid valves 5a and 5b for a certain period of time to cause them to close. However, the second valve closing instruction (continuous valve closing instruction) may be configured to continue applying the valve drive voltage to the latch-type solenoid valves 5a and 5b to cause them to close until the fire extinguishing process is completed or until the remaining time of the fire extinguishing process is less than the predetermined time S.

[0059] Next, I will explain some variations. (1) Variation 1 Modification 1 is a modification in which, in the above embodiment, the predetermined condition for issuing a continuous valve closing instruction 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 valve closing instruction process is executed.

[0060] 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 has been confirmed to be extinguished for the upper and lower burners 3a and 3b, and the process proceeds to step A, where a continuous closing 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 closing instruction have been met.

[0061] 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).

[0062] 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, the control unit 6 can close the latch-type solenoid valves 5a and 5b with a continuous closing instruction, preventing the gas from continuing to be released from the upper and lower burners 3a and 3b.

[0063] 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.

[0064] (2) Modification example 2 Modification 2 is a variation in which, in the above embodiment, the predetermined condition for issuing a continuous valve closing instruction 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 valve closing instruction process is executed.

[0065] 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 aforementioned 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 fire extinguishing of the upper and lower burners 3a and 3b has been confirmed, and the process proceeds to step A, which issues a continuous valve closing instruction after processing in step S6. In other words, even if a certain period of time (t2) has elapsed after the valve closing instruction for 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 valve closing instruction have been met.

[0066] 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).

[0067] 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, the control unit 6 can close the latch-type solenoid valves 5a and 5b with a continuous closing instruction, preventing the gas from continuing to be released from the upper and lower burners 3a and 3b.

[0068] 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.

[0069] 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.

[0070] For example, in this embodiment, 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 continuous valve closing instruction may be given to 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, the continuous valve closing instruction may be given to this latch-type solenoid valve.

[0071] In this embodiment, the combustion process involves burning both the upper burner 3a and the lower burner 3b, but it is also possible to burn only either the upper burner 3a or the lower burner 3b for all or part of the combustion process (including all or part of a single combustion process).

[0072] In the embodiment, a continuous valve closing instruction was given by applying a valve drive voltage to the latch-type solenoid valves 5a and 5b for a certain period of time at predetermined time intervals S (Step A). ​​However, in the present invention, as a continuous valve closing instruction, the valve drive voltage to close the latch-type solenoid valves 5a and 5b may be continuously applied until the fire extinguishing process is completed, or until the remaining time of the fire extinguishing process is less than the predetermined time S. The timing for starting this continuous application of the valve drive voltage to close the valve may be when first entering Step A, or when the valve closing instruction is given in Step S3.

[0073] The present invention may also be applied to a single-sided grilling device that has either an upper burner or a lower burner.

[0074] Furthermore, the present invention may also be applied to a gas stove. In this case, the gas stove is equipped with multiple stove burners, and the gas supply passage is branched to supply fuel gas to each stove burner. Each branched gas supply passage has a latch-type solenoid valve corresponding to the stove burner, and the control unit can be configured to issue open-valve instructions, closed-valve instructions, and continuous-valve-close instructions to each latch-type solenoid valve for each stove burner individually. That is, the control unit can be configured to perform a heat output control operation that alternately repeats the combustion process and the extinguishing process for some or all of the multiple stove burners, and to issue the continuous-valve-close instruction during this heat output control operation. In addition, in the case of stove burners that form a parent-child burner (such as a burner section that forms the flame hole stacked in several stages, or a burner section that forms the flame hole arranged in an annular shape inside and outside), the control unit can be configured to issue open-valve instructions, closed-valve instructions, and continuous-valve-close instructions to each latch-type solenoid valve for each burner section of the parent-child burner. [Explanation of Symbols]

[0075] 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 8a, 8b Flame detector (flame detection means) 9 Igniter 11 Temperature setting section 12 Timer setting section 13-point fire extinguishing switch 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, A flame detection means for detecting the combustion flame of the burner, The system includes a control unit that instructs the opening or closing of the latch-type solenoid valve, Combustion apparatus, wherein 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 to ignite the burner, and a fire extinguishing process in which the latch-type solenoid valve is closed by a close command to extinguish the burner, the control unit has a control configuration that issues an ignition command to the ignition means during the fire extinguishing process, and issues a continuous closing command to the latch-type solenoid valve when the flame detection means detects combustion of the burner.

2. In the combustion apparatus according to claim 1, The control unit, when the flame detection means detects that the burner has been extinguished at the start of the fire extinguishing process, executes a process of issuing a closing instruction to the latch-type solenoid valve as a continuous valve closing instruction, in a 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, when the temperature detection means detects predetermined temperature information and the fire extinguishing process is continuing, executes the process of issuing a closing instruction to the latch-type solenoid valve as a continuous valve closing instruction, in a combustion apparatus.

4. In the combustion apparatus according to any one of claims 1 to 3, The control unit issues a closing instruction to the latch-type solenoid valve at predetermined intervals as a continuous valve closing instruction, in this combustion apparatus.

5. In the combustion apparatus according to any one of claims 1 to 3, The control unit interrupts the continuous valve closing instruction after an opening instruction is given 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 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, The combustion apparatus comprises a control configuration that enables the control unit to individually issue opening instructions, closing instructions, and continuous closing instructions for each of the latch-type solenoid valves for each burner.

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

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