Fuel gas heating cooker

Abstract

A gas-fired cooking appliance (1) is provided that can efficiently utilize the heat generated by combustion even when cooking at high heat with both the main and auxiliary burners (10) burning simultaneously. When the user-set heat level increases, the appliance switches from a separate combustion state of the auxiliary burner (10C) to a simultaneous combustion state of the auxiliary burner and the main burner (10P). Furthermore, in the simultaneous combustion state, the gas flow rate of the fuel gas in the auxiliary burner is reduced or maintained as the set heat level increases. When used at high heat level, the auxiliary burner cannot efficiently utilize the heat generated by the combustion of fuel gas compared to the main burner. Therefore, by reducing or maintaining the gas flow rate of the auxiliary burner as the set heat level increases, the main burner is mainly used to burn fuel gas at high heat level, thus enabling efficient utilization of the heat generated by the combustion of fuel gas even at high heat level.

Description

Technical Field

[0001] The present invention relates to a gas heating cooker equipped with a main burner and a secondary burner, wherein the main burner and the secondary burner are coaxially configured, and the maximum heat output of the secondary burner is smaller than that of the main burner. Background Technology

[0002] A main and auxiliary burner is known, which is coaxially configured with a main burner and an auxiliary burner, the maximum heat output of which is smaller than that of the main burner. A gas-fired cooker equipped with this main and auxiliary burner supplies fuel gas exclusively to the auxiliary burner during periods requiring low heat output, thus burning the fuel gas solely with the auxiliary burner. When the required heat output increases, fuel gas is also supplied to the main burner, thus burning the fuel gas simultaneously with both the auxiliary and main burners. Furthermore, the state of burning fuel gas solely with the auxiliary burner is sometimes referred to as "single combustion state," and the state of burning fuel gas simultaneously with both the auxiliary and main burners is referred to as "simultaneous combustion state." Moreover, after switching to the simultaneous combustion state, as the required heat output increases, the flow rate of fuel gas supplied to the auxiliary and main burners increases, thereby increasing the heat output of both the auxiliary and main burners. By switching between the separate combustion state of the auxiliary burner and the simultaneous combustion state of the main and auxiliary burners in this way, a large heat output range can be achieved (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-281271 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, the gas-fired cooker mentioned above has the following problem: when cooking at high heat in a simultaneous combustion state, the heat generated by burning the fuel gases cannot be effectively utilized for cooking. The reason is as follows: the auxiliary burner is designed to enable cooking at a lower heat level than the main burner, and its efficiency in utilizing the heat generated by burning fuel gases for cooking is lower than that of the main burner. Nevertheless, when increasing the heat in a simultaneous combustion state, the amount of fuel gases burned in the auxiliary burner increases, thus increasing the amount of heat not used for cooking.

[0008] This invention was made to solve the aforementioned problems of the prior art, and its purpose is to provide a gas heating cooker that can efficiently utilize the heat generated by combustion even when cooking at high heat under the condition of simultaneous combustion of the main and auxiliary burners.

[0009] Solution for solving the problem

[0010] To solve the above problems, the gas-fired cooking appliance of the present invention adopts the following structure. That is, the gas-fired cooking appliance includes:

[0011] The main and auxiliary burners are configured coaxially, and the maximum firepower of the auxiliary burner is smaller than that of the main burner.

[0012] A main burner gas supply passage that supplies fuel gas to the main burner;

[0013] A secondary burner gas supply passage supplies fuel gas to the secondary burner;

[0014] A main burner gas flow regulating unit is inserted into the main burner gas supply passage to regulate the gas flow rate of the fuel gas supplied to the main burner.

[0015] A secondary burner gas flow regulating unit is inserted into the secondary burner gas supply passage for regulating the gas flow rate of the fuel gas supplied to the secondary burner; and

[0016] The control unit controls the main burner gas flow regulating unit and the auxiliary burner gas flow regulating unit.

[0017] The gas-fired cooking appliance is characterized in that the control unit performs the following actions:

[0018] The gas-fired cooker switches between a separate combustion mode and a simultaneous combustion mode based on the set power level set by the user. In the separate combustion mode, fuel gas is supplied to the auxiliary burner but not to the main burner. In the simultaneous combustion mode, fuel gas is supplied to both the auxiliary burner and the main burner.

[0019] In the simultaneous combustion state, as the set firepower increases, the gas flow rate of the main burner increases, while the gas flow rate of the auxiliary burner is maintained or reduced.

[0020] The gas-fired cooker of the present invention can operate in both a single-burner state and a simultaneous-burner state. In the single-burner state, fuel gas is supplied to the auxiliary burner but not the main burner, thus the fuel gas is burned only by the auxiliary burner. In the simultaneous-burner state, fuel gas is supplied to both the main burner and the auxiliary burner, thus the fuel gas is burned by both burners. During periods when the user-set heat is low, the fuel gas is burned in the single-burner state; when the set heat is increased, the fuel gas is burned in the simultaneous-burner state. Furthermore, in the simultaneous-burner state, as the user-set heat increases, the amount of fuel gas supplied to the main burner increases, while the amount of fuel gas supplied to the auxiliary burner is maintained or decreased.

[0021] As mentioned earlier, the auxiliary burner is not designed for high-power operation. Therefore, when used at high power, it cannot efficiently utilize the heat generated by burning fuel gas compared to the main burner. Thus, in the simultaneous combustion state of the main and auxiliary burners, as the user-set power level increases, the flow rate of fuel gas supplied to the auxiliary burner is reduced or maintained. This suppresses the amount of fuel gas burned by the auxiliary burner at high power, thus primarily utilizing the main burner. As a result, even when the simultaneous combustion state of the main and auxiliary burners is set to high power, the heat generated by burning fuel gas can be utilized efficiently.

[0022] Alternatively, in the gas-fired cooking appliance of the present invention described above, combustion at both the main and auxiliary burners can be initiated by igniting at least the fuel gas flowing from the auxiliary burner. Furthermore, at the start of combustion, the gas flow rate of the auxiliary burner is controlled to a predetermined auxiliary burner combustion start flow rate, and the gas flow rate of the main burner is controlled to a predetermined main burner combustion start flow rate. Alternatively, when igniting the auxiliary burner before combustion begins, the gas flow rate of the auxiliary burner can be controlled to a predetermined auxiliary burner ignition flow rate that is greater than the auxiliary burner combustion start flow rate.

[0023] This increases the gas flow rate supplied to the auxiliary burner during ignition, thus enabling reliable ignition of the auxiliary burner, which in turn reliably initiates combustion in both the main and auxiliary burners.

[0024] In addition, in the gas heating cooker of the present invention described above, a main and auxiliary burner with an auxiliary burner formed below the main burner may also be provided.

[0025] Because the auxiliary burner is located below the main burner, its flame forms further away from the bottom of the cooking container than the main burner's flame. Consequently, the auxiliary burner is less efficient at heating the container compared to the main burner. Therefore, in a simultaneous combustion state with both the auxiliary and main burners, if the gas flow rate of the auxiliary burner is reduced or maintained as the set heat level increases, the main burner will primarily burn the fuel gas at high heat levels. As a result, even with high heat levels during simultaneous combustion, the heat generated by combustion can be utilized efficiently. Attached Figure Description

[0026] Figure 1 This is a perspective view showing the external shape of the gas heating cooker 1 equipped with the main and auxiliary burners 10 in this embodiment.

[0027] Figure 2 This is a perspective view showing the general shape of the main and auxiliary burners 10 in this embodiment.

[0028] Figure 3 This is an exploded assembly diagram showing the internal structure of the burner body 11b and burner cover 20 of the main and auxiliary burners 10 in this embodiment.

[0029] Figure 4 This is an explanatory diagram showing how the gas heating cooker 1 of this embodiment controls the gas flow rate of the fuel gas supplied to the main burner 10P and the auxiliary burner 10C.

[0030] Figure 5 This is an explanatory diagram showing how the gas heating cooker 1 of the first modified example controls the gas flow rate of the fuel gas supplied to the main burner 10P and the auxiliary burner 10C.

[0031] Figure 6 This is an explanatory diagram showing the situation where the gas heating cooker 1 of this embodiment and the second modification controls the gas flow rate of the fuel gas supplied to the main burner 10P and the auxiliary burner 10C after combustion begins.

[0032] Figure 7 This is an explanatory diagram showing how the gas flow rate of the fuel gas supplied to the main burner 10P and the auxiliary burner 10C is controlled in the second modified gas heating cooker 1.

[0033] Figure 8 This is an explanatory diagram showing the control of the gas flow rate of fuel gas supplied to the main burner 10P and the auxiliary burner 10C in the third modified gas heating cooker 1. Detailed Implementation

[0034] Figure 1 This is a perspective view showing the external shape of the gas heating cooker 1 equipped with the main and auxiliary burners 10 in this embodiment. Figure 1 The gas-heated cooker 1 illustrated is an embedded gas-heated cooker 1 that is installed in the countertop of an integrated kitchen (not shown), and has a box-shaped cooker body 2 and a top plate 3 that is installed to cover the upper surface of the opening of the cooker body 2.

[0035] Inside the main body 2 of the stove, two main and auxiliary burners 10 are housed side by side. These main and auxiliary burners 10 are combined in two layers, described later, with their upper parts protruding from through-holes formed in the top plate 3. Furthermore, a burner rack 4 is provided on the top plate 3, surrounding the upper protruding parts of each main and auxiliary burner 10. By placing cooking containers such as pots on the burner rack 4, the cooking containers can be heated from below by the main and auxiliary burners 10. A temperature sensor 5 is embedded in the center of each main and auxiliary burner 10. The temperature sensor 5 is pushed upwards by a force spring (not shown), causing its upper part to protrude from the center of the upper surface of the main and auxiliary burner 10. Moreover, when a cooking container is placed on the burner rack 4, the bottom surface of the cooking container presses down on the temperature sensor 5, so that the upper end of the temperature sensor 5 is in contact with the bottom surface of the cooking container, enabling the detection of the cooking container's temperature.

[0036] Additionally, a grill door 7 is provided on the front surface of the gas-heated cooker 1, inside which a grill chamber (not shown) and a grill burner are housed. To the right of the grill door 7, two cooker operation buttons 8 are provided corresponding to the two main and auxiliary burners 10. The user of the gas-heated cooker 1 can operate either cooker operation button 8 to ignite, extinguish, or adjust the heat of the corresponding main and auxiliary burner 10. Furthermore, a grill operation button 9 is provided to the left of the grill door 7, allowing the user to ignite, extinguish, or adjust the heat of the grill burner.

[0037] Figure 2 This is a perspective view showing the general shape of the main and auxiliary burners 10 of this embodiment. As shown, the main and auxiliary burners 10 include a burner body 11 formed by assembling sheet metal components and a generally cylindrical burner cover 20. The burner body 11 has a generally cylindrical burner body 11b, a main mixing pipe 12 connected to the burner body 11b, and an auxiliary mixing pipe 13 with a smaller diameter than the main mixing pipe 12 connected to the burner body 11b. The burner cover 20 is mounted on the burner body 11b. A through hole 20h is formed in the center of the burner cover 20, into which a previously used... Figure 1 The temperature sensor 5 has been described.

[0038] The burner cover 20 is a component divided into upper and lower layers, formed using aluminum alloy or brass through casting or die casting. The upper component constituting the burner cover 20 will be referred to as the upper cover portion 21, and the lower component as the lower cover portion 22. With the upper cover portion 21 placed on top of the lower cover portion 22 as shown in the figure, ... Figure 2 As shown in the magnified view, a plurality of upper flame ports 21f are formed on the outer peripheral surface of the upper cover portion 21, and a plurality of lower flame ports 22f are formed on the outer peripheral surface of the lower cover portion 22. Furthermore, the upper cover portion 21 and the lower cover portion 22 are combined in such a way that the upper flame ports 21f and the lower flame ports 22f are located in mutually offset positions.

[0039] Furthermore, when the burner cover 20 is placed on the burner body 11b, a plurality of small flame ports (hereinafter referred to as secondary flame ports 22u) are formed between the lower cover portion 22 and the burner body 11b. As described later, a space connected to the main mixing pipe 12 and a space connected to the secondary mixing pipe 13 are formed inside the burner body 11b. Moreover, the secondary flame ports 22u formed between the lower cover portion 22 and the burner body 11b communicate with the space connected to the secondary mixing pipe 13. In addition, the upper flame port 21f formed on the upper cover portion 21 and the lower flame port 22f formed on the lower cover portion 22 communicate with the space connected to the main mixing pipe 12. Therefore, as described later, when fuel gas is supplied to the secondary mixing pipe 13, the fuel gas flows out from the secondary flame ports 22u, and when fuel gas is supplied to the main mixing pipe 12, the fuel gas flows out from the upper flame port 21f and the lower flame port 22f.

[0040] Fuel gas is supplied to the main mixing pipe 12 and the auxiliary mixing pipe 13 as follows. First, the side of the main mixing pipe 12 that is not connected to the burner body 11b is an open end 12o, and the side of the auxiliary mixing pipe 13 that is not connected to the burner body 11b is also an open end 13o. A gas injection nozzle 43p is provided near the open end 12o of the main mixing pipe 12, and a gas injection nozzle 43c is provided near the open end 13o of the auxiliary mixing pipe 13. Furthermore, the gas injection nozzle 43p on the main mixing pipe 12 side is sometimes referred to as the "main-side gas injection nozzle 43p," and the gas injection nozzle 43c on the auxiliary mixing pipe 13 side is sometimes referred to as the "auxiliary-side gas injection nozzle 43c." Moreover, the main-side gas injection nozzle 43p is connected to a connecting pipe 40p, and the auxiliary-side gas injection nozzle 43c is connected to a connecting pipe 40c. These two connecting pipes 40p and 40c branch off from the gas supply pipe 40. In addition, the connecting pipe 40p with the main side gas injection nozzle 43p installed at the top is sometimes referred to as the "main side connecting pipe 40p", and the connecting pipe 40c with the auxiliary side gas injection nozzle 43c installed at the top is referred to as the "auxiliary side connecting pipe 40c".

[0041] When fuel gas is supplied to the gas supply pipe 40, the fuel gas branches to the main connecting pipe 40p and the secondary connecting pipe 40c, and is then supplied to the main gas injection nozzle 43p and the secondary gas injection nozzle 43c. Then, when fuel gas is injected from the main gas injection nozzle 43p toward the opening 12o of the main mixing pipe 12, the fuel gas, due to the injector effect, carries surrounding air into the main mixing pipe 12, mixes with air within the main mixing pipe 12, and then flows out from the upper flame port 21f and the lower flame port 22f. Similarly, when fuel gas is injected from the secondary gas injection nozzle 43c toward the opening 13o of the secondary mixing pipe 13, the fuel gas, due to the injector effect, carries surrounding air into the secondary mixing pipe 13, mixes with air within the secondary mixing pipe 13, and then flows out from the secondary flame port 22u.

[0042] Additionally, a gas flow regulating valve 42p for adjusting the flow rate of fuel gas supplied to the main burner 10P is installed midway along the main connecting pipe 40p, and a gas flow regulating valve 42c for adjusting the flow rate of fuel gas supplied to the auxiliary burner 10C is installed midway along the secondary connecting pipe 40c. Furthermore, an electromagnetic on / off valve 41 is installed on the gas supply pipe 40. When fuel gas is supplied to the main burner 10P or the auxiliary burner 10C, the electromagnetic on / off valve 41 is open, which in turn opens the gas flow regulating valve 42p on the main connecting pipe 40p or the gas flow regulating valve 42c on the secondary connecting pipe 40c. Conversely, when fuel gas is not supplied to the main burner 10P or the auxiliary burner 10C, the electromagnetic on / off valve 41 is closed. Furthermore, the gas flow regulating valve 42p installed on the main side connecting pipe 40p is sometimes referred to as the "main side gas flow regulating valve 42p", and the gas flow regulating valve 42c installed on the secondary side connecting pipe 40c is referred to as the "secondary side gas flow regulating valve 42c". Additionally, various known valves capable of regulating gas flow in a continuous or multi-stage manner can be used as the main side gas flow regulating valve 42p and the secondary side gas flow regulating valve 42c. In this embodiment, a flow regulating valve driven by a stepper motor is used.

[0043] Furthermore, in this embodiment, the main-side connecting pipe 40p corresponds to the "main burner gas supply passage" in this invention, and the secondary-side connecting pipe 40c corresponds to the "secondary burner gas supply passage" in this invention. Also, the main-side gas flow regulating valve 42p corresponds to the "main burner gas flow regulating unit" in this invention, and the secondary-side gas flow regulating valve 42p corresponds to the "secondary burner gas flow regulating unit" in this invention.

[0044] Furthermore, a spark plug 30 and a flame sensor 32 are provided on the burner body 11. These two components are located near the outer peripheral surface of the burner body 11b and are connected to the control unit 50. An ignition target 31 protrudes from the outer peripheral surface of the burner cover 20 above the spark plug 30. When the control unit 50 opens the electromagnetic valve 41 of the gas supply pipe 40, performs a spark discharge from the spark plug 30 to the ignition target 31, and simultaneously opens the secondary gas flow regulating valve 42c, fuel gas flows out from the secondary flame port 22u, ignites, and combustion begins. The flame sensor 32 can detect the flame generated at the secondary flame port 22u, and the control unit 50 can identify the start of combustion by detecting the flame at the secondary flame port 22u. In addition, the control unit 50 of this embodiment corresponds to the "control unit" in this invention. Furthermore, the spark plug 30 of this embodiment corresponds to the "ignition unit" in this invention.

[0045] like Figure 2 As shown, the upper flame port 21f and the lower flame port 22f are set to have a larger opening area than the auxiliary flame port 22u. Furthermore, the main mixing pipe 12, which communicates with the upper flame port 21f and the lower flame port 22f inside the burner body 11, is formed with a diameter larger than that of the auxiliary mixing pipe 13, which communicates with the auxiliary flame port 22u. Therefore, a greater amount of fuel gas can be burned at the upper flame port 21f and the lower flame port 22f than at the auxiliary flame port 22u, thereby generating high heat output. Therefore, the main and auxiliary burners 10 are used in the following manner: fuel gas is burned at the auxiliary flame port 22u when low heat output is required, and fuel gas is burned at the upper flame port 21f and the lower flame port 22f when high heat output is required. Therefore, the portion of the main and auxiliary burners 10 with the auxiliary flame port 22u is referred to as "auxiliary burner 10C", and the portion of the main and auxiliary burners 10 with the upper flame port 21f and the lower flame port 22f is referred to as "main burner 10P".

[0046] In addition, such as Figure 2 As shown, in this embodiment, the main burner 10 and the auxiliary burner 10C are arranged in two layers on the same axis, one above the other. However, the main burner 10P and the auxiliary burner 10C do not necessarily have to be arranged in two layers. For example, the main burner 10 can also be configured as follows: the auxiliary burner 10C with a smaller diameter than the main burner 10P is arranged inside the annular main burner 10P. In addition, the main burner 10 in this embodiment forms two layers of flame ports by arranging the upper flame port 21f and the lower flame port 22f of the main burner 10P in a serrated shape. However, it is not limited to this. The upper flame port 21f and the lower flame port 22f of the main burner 10P can also be arranged in an aligned state to form a single layer of flame ports.

[0047] Figure 3This is an exploded assembly view showing the internal structure of the burner body 11b and burner cover 20 of the main and auxiliary burners 10 in this embodiment. As shown, the generally cylindrical burner body 11b forms an annular mounting surface 11a for mounting the burner cover 20 by bending the upper end side inward. In addition, a cylindrical central cylinder 14 is erected inside the burner body 11b, and an annular mixing chamber 16 for supplying mixed combustion gas is formed between the burner body 11b and the central cylinder 14.

[0048] Furthermore, a generally cylindrical partition 15 is provided between the burner body 11b and the central cylinder 14. The mixing chamber 16 is divided by this partition 15 into a space inside the partition 15 and a space outside the partition 15. The space inside the partition 15 is the main mixing chamber 16p, which will be described later, and the space outside the partition 15 is the secondary mixing chamber 16c, which will be described later. The partition 15, like the burner body 11b, is formed of a metal plate component. A short cylindrical fitting surface 15a is formed by bending the upper side of the cylindrical shape inward and then bending the inner side downward.

[0049] As described above, the burner cover 20 includes an upper cover portion 21 and a lower cover portion 22. The lower cover portion 22 is mounted on the mounting surface 11a of the burner body 11b, and the upper cover portion 21 is mounted on the lower cover portion 22. As shown in the figure, the lower cover portion 22 is a generally annular component, with a cylindrical partition tube 22a hanging downward from its inner edge. Furthermore, a plurality of lower grooves 22b are formed on the lower surface of the outer edge portion (the surface that abuts against the mounting surface 11a of the burner body 11b) in a radial pattern relative to the center of the lower cover portion 22.

[0050] Furthermore, an upwardly projecting cylindrical wall 22c is provided on the outer edge of the lower cover portion 22, and a plurality of lower grooves 22d are formed on the upper end surface of the upwardly projecting cylindrical wall 22c in a radial pattern relative to the center of the upwardly projecting cylindrical wall 22c. However, no lower grooves 22d are provided at positions facing the plurality of claw portions of the spark plug 4. Additionally, an ignition target 31 protrudes from the outer peripheral surface of the upwardly projecting cylindrical wall 22c above the aforementioned spark plug 30.

[0051] On the other hand, the upper cover portion 21 is formed in an annular shape, and a cylindrical inner cylinder (not shown) hangs downward from the inner edge portion. Furthermore, a downward-facing cylindrical wall 21a is provided, extending downward from the outer edge portion, and a plurality of upper grooves 21b are formed on the lower end surface of the downward-facing cylindrical wall 21a in a radial pattern relative to the center of the downward-facing cylindrical wall 21a. Additionally, like the lower grooves 22d described above, the upper grooves 21b are not located in positions facing the plurality of claw portions of the fire frame 4.

[0052] The upper cover 21 and the lower cover 22 are combined in a manner where the upper groove 21b of the upper cover 21 and the lower groove 22d of the lower cover 22 do not overlap. Therefore, when the upper cover 21 and the lower cover 22 are combined to form the burner cover 20, an upper flame port 21f is formed in the portion of the upper groove 21b that opens towards the outer peripheral surface of the lower cylindrical wall 21a, and a lower flame port 22f is formed in the portion of the lower groove 22d that opens towards the outer peripheral surface of the upper cylindrical wall 22c (see reference). Figure 2 Furthermore, since the upper groove 21b and the lower groove 22d are positioned so that they do not overlap, the upper flame port 21f and the lower flame port 22f are formed in offset positions.

[0053] When placing the burner cover 20 onto the burner body 11b, firstly, the partition wall cylinder 22a, which hangs downward from the inner edge of the lower cover portion 22, is inserted into the inner side of the fitting surface 15a of the partition cylinder 15, and the inner cylinder (not shown), which hangs downward from the inner edge of the upper cover portion 21, is inserted into the inner side of the central cylinder 14, while simultaneously lowering the burner cover 20. Then, the lower groove 22b formed on the lower surface of the outer edge of the lower cover portion 22 abuts against the mounting surface 11a of the burner body 11b, and the burner cover 20 is placed onto the burner body 11b.

[0054] With the burner cover 20 placed on the burner body 11b, the following conditions are met: the partition wall cylinder 22a of the lower cover 22 is fitted into the fitting surface 15a of the partition cylinder 15, and the inner cylinder (not shown) of the upper cover 21 is fitted into the inner circumferential surface of the upper part of the central cylinder 14. As a result, a sub-mixing chamber 16c is formed on the outside of the partition cylinder 15, surrounded by the partition cylinder 15, the burner body 11b, and the lower cover 22. This sub-mixing chamber 16c communicates with the sub-mixing pipe 13. Furthermore, a main mixing chamber 16p is formed on the inside of the partition cylinder 15, surrounded by the central cylinder 14, the partition cylinder 15, the partition wall cylinder 22a, and the upper cover 21. This main mixing chamber 16p communicates with the main mixing pipe 12.

[0055] In this embodiment, with the structure described above, the main and auxiliary burners 10 maintain the main-side gas flow regulating valve 42p closed and open the solenoid valve 41 and the auxiliary-side gas flow regulating valve 42c during periods of low required heat output, thereby using only the auxiliary burner 10C to burn fuel gas. Then, as the required heat output increases, the opening of the auxiliary-side gas flow regulating valve 42c increases, thereby gradually increasing the heat output of the auxiliary burner 10C. Furthermore, when the required heat output exceeds a predetermined level, the main-side gas flow regulating valve 42p also opens, thereby starting to burn fuel gas using the main burner 10P as well. In this way, a large heat output range from low to high is achieved. Furthermore, the state where the auxiliary burner 10C burns fuel gas but the main burner 10P does not burn fuel gas is referred to as a separate combustion state. Additionally, the state where both the auxiliary burner 10C and the main burner 10P burn fuel gas is referred to as a simultaneous combustion state.

[0056] Two stove operation buttons 8 (see reference) are mounted on the front surface of the gas heating cooker 1. Figure 1 )and Figure 2 The control unit 50 shown is connected, and is also connected to the solenoid valve 41, the main gas flow regulating valve 42p, and the auxiliary gas flow regulating valve 42c. When the user of the gas heating cooker 1 operates the stove operation button 8 to perform a prescribed ignition operation for igniting the main and auxiliary burners 10, the control unit 50 detects the ignition operation and opens the solenoid valve 41, the main gas flow regulating valve 42p, and the auxiliary gas flow regulating valve 42c, and releases gas from the spark plug 30 (see reference). Figure 2 A spark is emitted, thus initiating combustion at the main and auxiliary burners 10. Then, when the user of the gas-heated cooker 1 operates the stove operation button 8 to set the heat level for heating and cooking (i.e., set heat level), while the main and auxiliary burners 10 are already burning, the control unit 50 acquires this set heat level and adjusts the opening of the main-side gas flow regulating valve 42p and the auxiliary-side gas flow regulating valve 42c accordingly. In this way, fuel gas of appropriate flow rate is supplied to the main burner 10P and the auxiliary burner 10C according to the set heat level, and the fuel gas is burned by the main burner 10P and the auxiliary burner 10C.

[0057] Figure 4 This is an explanatory diagram showing how the control unit 50, mounted on a gas-fired cooker 1, controls the flow rate of fuel gas supplied to the main burner 10P and the auxiliary burner 10C according to the user-set power level. Figure 4 The system displays the user-set firepower in stages, from P1 (minimum firepower) to P6 (maximum firepower). Alternatively, the firepower setting can be continuously changed. Additionally, in... Figure 4(a) shows the situation where the control unit 50 controls the gas flow rate in this embodiment. Figure 4 (b) shows, for reference, the control unit of a conventional gas-heated cooking appliance controlling the gas flow.

[0058] Furthermore, as a convention, the flow rate of fuel gas is not expressed as the weight or volume of fuel gas passing through per unit time, but rather as the calorific value generated during the combustion of the fuel gas. Correspondingly, in Figure 4 (a) and Figure 4 In (b), the fuel gas flow rate is displayed using the input (kcal / h) representing the calorific value of the fuel gas per unit time. Additionally, Figure 4 (a) and Figure 4 The “overall input” shown on the vertical axis of (b) is the value obtained by summing the input to the main burner 10P and the input to the auxiliary burner 10C (i.e., the input as a whole for the main and auxiliary burners 10).

[0059] For ease of explanation, firstly... Figure 4 The previous situation shown in (b) will be explained. Figure 4 As shown in (b), in conventional gas-fired cookers, when the user sets the power level to the minimum P1, fuel gas at a flow rate of approximately 300 kcal / h is supplied to the auxiliary burner 10C by keeping the main gas flow regulating valve 42p closed and opening the secondary gas flow regulating valve 42c. Furthermore, when the power level is increased to P2, the flow rate of fuel gas supplied to the auxiliary burner 10C is increased to approximately 650 kcal / h by keeping the main gas flow regulating valve 42p closed and increasing the opening of the secondary gas flow regulating valve 42c. Thus, when the power level is set to P1 or P2, fuel gas is supplied only to the auxiliary burner 10C, not the main burner 10P. Therefore, the auxiliary burner 10C operates in a separate combustion state, where the fuel gas is burned independently. In this separate combustion state, the gas flow rate supplied to the auxiliary burner 10C is itself the overall input.

[0060] Furthermore, when the setpoint is P3, the overall input is increased to approximately 1400 kcal / h by opening the main-side gas flow regulating valve 42p. The input distribution between the auxiliary burner 10C and the main burner 10P is as follows: the input to the auxiliary burner 10C is reduced to approximately 300 kcal / h (or even less, approximately 250 kcal / h) when the setpoint is P1, with the remainder borne by the main burner 10P. Therefore, when the setpoint increases from P2 to P3, control is achieved by reducing the opening of the auxiliary-side gas flow regulating valve 42c to the minimum setpoint (or a smaller opening) and changing the main-side gas flow regulating valve 42p from a closed state to an open state. Additionally, when the setpoint is P3, the fuel gas is burned simultaneously using both the auxiliary burner 10C and the main burner 10P.

[0061] Furthermore, when the power output is increased to P4, the overall input is increased to approximately 2150 kcal / h by increasing the valve openings of the main gas flow regulating valve 42p and the secondary gas flow regulating valve 42c. Moreover, when the power output is increased to P5, the overall input is increased to approximately 3000 kcal / h by further increasing the valve openings of the main gas flow regulating valve 42p and the secondary gas flow regulating valve 42c. When the power output is increased to P6, the valve openings of the main gas flow regulating valve 42p and the secondary gas flow regulating valve 42c are increased to bring the overall input to approximately 4300 kcal / h.

[0062] Thus, in conventional gas-fired cookers, as the heat output increases during simultaneous combustion, the input to both the main burner 10P and the auxiliary burner 10C also increases. However, since the auxiliary burner 10C was originally designed for cooking at a lower heat output than the main burner 10P can achieve, it cannot efficiently utilize the heat generated by combustion for cooking when used at a high heat output set to P5 or P6.

[0063] Therefore, in the gas-heated cooker 1 of this embodiment, the heat is set according to the power setting set by the user of the gas-heated cooker 1, as follows: Figure 4 The inputs to the main burner 10P and the auxiliary burner 10C are controlled in the manner shown in (a). That is, when the firepower is set to P1 or P2 (i.e., in the case of independent combustion), the inputs are controlled in the manner described above. Figure 4 The control is the same as that described in (b) of the conventional gas-heated cooker. In addition, it is also the same as the conventional gas-heated cooker in that it switches to simultaneous combustion mode when the set heat becomes greater than P3.

[0064] However, in the gas-fired cooker 1 of this embodiment, the opening of the secondary gas flow regulating valve 42c is controlled as follows: as the set heat intensity increases from P3, the input of the secondary burner 10C decreases. Furthermore, the opening of the primary gas flow regulating valve 42p is controlled to be the same as that of a conventional gas-fired cooker, specifically: approximately 1400 kcal / h when the set heat intensity is P3, approximately 2150 kcal / h when the set heat intensity is P4, approximately 3000 kcal / h when the set heat intensity is P5, and approximately 4300 kcal / h when the set heat intensity is P6.

[0065] In that case, such as Figure 4 As shown in (a), under high heat settings such as P5 or P6, the fuel gas supplied to the auxiliary burner 10C is suppressed, and the fuel gas corresponding to the suppressed amount is burned by the main burner 10P. Since the main burner 10P is designed for high-heat cooking, it can utilize the heat generated by combustion more efficiently than the auxiliary burner 10C during high-heat cooking. Therefore, in the gas-fired cooker 1 of this embodiment, even when the heat setting is high such as P5 or P6, the heat generated by burning fuel gas can be used efficiently for cooking.

[0066] Additionally, in the gas-heated cooker 1 of this embodiment, such as Figure 2 As shown, the auxiliary burner 10C is formed below the main burner 10P. The flame of the auxiliary burner 10C is formed at a position farther from the bottom surface of the cooking container than the flame of the main burner 10P. Therefore, compared with the main burner 10P, the auxiliary burner 10C cannot efficiently utilize the heat generated by combustion for heating and cooking. Thus, by suppressing the fuel gas burned by the auxiliary burner 10C at high heat and burning that suppressed amount of fuel gas with the main burner 10P, the heat generated by combustion can be efficiently utilized for heating and cooking even at high heat.

[0067] Furthermore, in the gas-fired cooker 1 of this embodiment, it is also possible to prevent the generation of a yellow flame in the auxiliary burner 10C when the heat is low during simultaneous combustion (when the heat is set to P3). This is based on the following reasons. First, as Figure 4As shown in (b), when the set power increases from P2 to P3, the input to the secondary burner 10C decreases sharply to the same level as (or less than) the minimum power P1. Therefore, the flow rate of fuel gas ejected from the secondary-side gas injection nozzle 43c also decreases, resulting in less air being entrained in the fuel gas and flowing into the secondary mixing tube 13 due to the injector effect. Furthermore, unlike the minimum power P1 state, at the set power P3 state, air also flows into the main mixing tube 12 due to the injector effect, thus reducing the amount of air flowing into the secondary mixing tube 13. Consequently, when the set power is P3, the flow rate of air flowing into the secondary mixing tube 13 tends to be insufficient relative to the fuel gas flow rate, leading to a tendency for combustion conditions to deteriorate in the secondary burner 10C, resulting in a yellow flame.

[0068] In contrast, in the gas-fired cooking appliance 1 of this embodiment, such as Figure 4 As shown in (a), the input of the auxiliary burner 10C when the power setting is P3 is greater than the input when the power setting is the minimum, P1. Therefore, even if the power setting is changed from P2 to P3, the gas flow rate injected from the auxiliary gas injector 43c does not decrease drastically, thus sufficient air can be drawn into the auxiliary mixing tube 13 through the injector effect. Similarly, in the gas heating cooker 1 of this embodiment, when the power setting is changed to P3, the main gas injector 43p also injects fuel gas, so air also flows into the main mixing tube 12, but... Figure 4 Compared to conventional gas-fired cookers shown in (b), the flow rate of fuel gas injected from the main gas injection nozzle 43p is smaller, thus reducing the amount of air flowing into the main mixing tube 12. Therefore, even with air being drawn into the main mixing tube 12, insufficient air intake into the secondary mixing tube 13 is less likely to occur. As a result, in the gas-fired cooker 1 of this embodiment, even when the power setting is P3, insufficient air intake into the secondary mixing tube 13 is not observed, thus preventing the formation of a yellow flame in the secondary burner 10C.

[0069] The gas-fired cooking appliance 1 of the above embodiment has several variations. These variations will be described below with a focus on their differences from this embodiment.

[0070] In the gas-fired cooker 1 of this embodiment described above, it was explained that when the simultaneous combustion state is entered, the input of the auxiliary burner 10C decreases as the set heat level increases. However, it is also possible to maintain the input of the auxiliary burner 10C at a constant value in the simultaneous combustion state.

[0071] Figure 5This is an explanatory diagram of a first modified example of the input to the auxiliary burner 10C, which maintains simultaneous combustion. (See diagram for example.) Figure 5 As shown, in the gas-fired cooker 1 of the first modified example, when the set power is changed from P2 to P3, the input of the auxiliary burner 10C decreases. However, the reduced input is greater than the input when the set power is P1, and the input remains constant even if the set power is increased from P3 to P4, P5, or P6.

[0072] Similarly, even if the heat setting is set to a high level such as P5 or P6, the amount of fuel gas burned by the secondary burner 10C does not increase, thus avoiding the situation where the heat cannot be effectively utilized for cooking.

[0073] Furthermore, in the above-described embodiment and the first modified example, it was explained that even if the set fire power is increased, the input of the auxiliary burner 10C does not increase when the simultaneous combustion state is in progress. However, it is also possible to increase the input of the auxiliary burner 10C at the start of ignition, thereby temporarily increasing the input of the auxiliary burner 10C when the set fire power is increased.

[0074] First, the operation of the gas-fired cooker 1 in this embodiment and the first modified embodiment when igniting the main and auxiliary burners 10 to start combustion will be explained. When starting combustion of fuel gas using the main and auxiliary burners 10, fuel gas is supplied to both the auxiliary burner 10C and the main burner 10P while a spark is emitted from the spark plug 30 to ignite the fuel gas flowing from the auxiliary burner 10C. A flame is then formed in the auxiliary burner 10C, and this flame ignites the fuel gas flowing from the main burner 10P. As a result, combustion of the fuel gas at the main and auxiliary burners 10 begins.

[0075] Furthermore, at the start of combustion, the burner cap 20 and burner body 11b are generally not yet hot, so combustion at the auxiliary burner 10C and main burner 10P tends to be unstable. Therefore, to stabilize combustion, the heat setting is automatically set to a high heat at the start of combustion. For example, in the gas-heated cooker 1 of this embodiment, such as... Figure 6 As shown, the automatic setting of the flame at the start of combustion (i.e., even if the user does not set it) is set to flame level P4. Furthermore, after combustion has started at the main and auxiliary burners 10 (before the user changes the flame setting), the auxiliary burner 10C and the main burner 10P are supplied with gas flow rates corresponding to the flame setting of P4. The flame setting that is automatically set at the start of combustion will be referred to as the "combustion start flame setting". Additionally, the gas flow rate supplied to the auxiliary burner 10C at the combustion start flame setting will be referred to as the "auxiliary burner combustion start flow rate", and the gas flow rate supplied to the main burner 10P at the combustion start flame setting will be referred to as the "main burner combustion start flow rate".

[0076] Alternatively, during the period when a spark is emitted from the spark plug 30 to initiate combustion at the main and auxiliary burners 10, the gas flow rate supplied to the auxiliary burner 10C may be greater than the initial combustion flow rate of the auxiliary burner. Or, not in the middle of the spark emission period, but at the beginning of the spark emission period, the gas flow rate supplied to the auxiliary burner 10C may be greater than the initial combustion flow rate of the auxiliary burner.

[0077] Figure 7 This is an explanatory diagram illustrating the situation where the gas flow rate of the auxiliary burner 10C increases when the main and auxiliary burners 10 are ignited in this second variation of the gas-heated cooker 1. Figure 7 Similarly, in the second modified example of the gas-fired cooker 1 shown, the power level is automatically set to P4 at the start of combustion. Therefore, when combustion begins at the main and auxiliary burners 10, the power level is the same as that used previously. Figure 6 Similarly, in the described embodiment, the gas flow rate of the auxiliary burner 10C is set to the auxiliary burner combustion start-up flow rate. However, during the period when a spark is being emitted by the spark plug 30 to initiate combustion (or in the early stages of that period), the gas flow rate of the auxiliary burner 10C is increased to a predetermined auxiliary burner ignition flow rate greater than the auxiliary burner combustion start-up flow rate. Figure 7 In the diagram, the ignition flow rate of the auxiliary burner is represented by a dashed line. As a result, the gas flow rate of the auxiliary burner 10C during ignition becomes greater than the gas flow rate of the auxiliary burner 10C when the set fire power P3 is set.

[0078] Thus, if the gas flow rate of the auxiliary burner 10C is increased during ignition, the fuel gas flowing out of the auxiliary burner 10C can be reliably ignited. Moreover, if the auxiliary burner 10C can be reliably ignited, the fuel gas flowing out of the main burner 10P can be reliably ignited, and thus combustion in both the main and auxiliary burners 10 can be reliably started.

[0079] In addition, Figure 7 In the example shown, it is assumed that even during the period when the fuel gas in the auxiliary burner 10C is increased at ignition, the overall gas flow rate (overall input) of both the auxiliary burner 10C and the main burner 10P remains unchanged. Therefore, during the period when the gas flow rate of the auxiliary burner 10C is increased, the gas flow rate of the main burner 10P decreases accordingly. However, it is also possible that even during the period when the gas flow rate of the auxiliary burner 10C is increased, the gas flow rate of the main burner 10P remains at the main burner combustion start flow rate (refer to...). Figure 6 In this way, it is not necessary to change the gas flow rate of both the auxiliary burner 10C and the main burner 10P, thus reducing the control burden on the control unit 50.

[0080] Furthermore, in the above-described embodiment, first modified example, and second modified example, it was explained that the gas flow rate of the auxiliary burner 10C was reduced or maintained as the set fire power increased during simultaneous combustion (and therefore, the same applies when the set fire power is at its maximum, P6). However, it is also possible to increase the gas flow rate of the auxiliary burner 10C when the set fire power is at its maximum, P6.

[0081] Figure 8 This is an explanatory diagram of a third variation of a gas-heated cooker 1, where the gas flow rate of the auxiliary burner 10C is increased under the maximum set heat. Furthermore, in... Figure 8 In the simultaneous combustion state, within the range of P3 to P5 (below the maximum set firepower of P6), the gas flow rate of the auxiliary burner 10C decreases as the set firepower increases. However, it is also possible that the gas flow rate of the auxiliary burner 10C remains constant within the range of P3 to P5.

[0082] like Figure 8 As shown, in the gas-fired cooker 1 of the third variation, when simultaneous combustion begins, as long as the maximum set heat level P6 is not reached, the gas flow rate of the auxiliary burner 10C decreases as the set heat level increases. As mentioned earlier, when used at high heat level, the auxiliary burner 10C cannot efficiently utilize the heat generated by combustion for heating. Therefore, if the gas flow rate of the auxiliary burner 10C decreases as the set heat level increases, the heat generated by combustion can be efficiently utilized for heating at high heat level. On the other hand, at the maximum set heat level, fuel gas can be burned not only by the main burner 10P but also by the auxiliary burner 10C (although the heat utilization efficiency decreases), thus achieving a higher heat level.

[0083] The gas-heated cooker 1 of this embodiment and various modifications has been described above. However, the present invention is not limited to the above embodiments and modifications and can be implemented in various ways without departing from its spirit.

[0084] Explanation of reference numerals in the attached figures

[0085] 1: Gas heating cooker; 2: Cooker body; 3: Top plate; 4: Burner rack; 5: Temperature sensor; 7: Grill rack door; 8: Cooker operation button; 9: Grill rack operation button; 10: Main and auxiliary burners; 10C: Auxiliary burner; 10P: Main burner; 11: Burner body; 11a: Supporting surface; 11b: Burner body; 12: Main mixing tube; 12o: Open end; 13: Auxiliary mixing tube; 13o: Open end; 14: Central cylinder; 15: Dividing cylinder; 15a: Fitting surface; 16: Mixing chamber; 16c: Auxiliary mixing chamber; 16p: Main mixing chamber; 20: Burner cover; 20h: Insertion point 21: Upper cover; 21a: Lower cylindrical wall; 21b: Upper groove; 21f: Upper flame port; 22: Lower cover; 22a: Divider cylinder; 22b: Lower groove; 22c: Upper cylindrical wall; 22d: Lower groove; 22f: Lower flame port; 22u: Secondary flame port; 30: Spark plug; 31: Ignition target; 32: Flame sensor; 40: Gas supply pipe; 40c: Connecting pipe; 40p: Connecting pipe; 41: Electromagnetic on / off valve; 42c: Gas flow regulating valve; 42p: Gas flow regulating valve; 43c: Gas injection nozzle; 43p: Gas injection nozzle; 50: Control unit.

Claims

1. A gas heating cooker comprising: a primary and secondary burner, the primary and secondary burner being configured with a primary burner and a secondary burner coaxially arranged, the maximum gas flow rate of the secondary burner being smaller than that of the primary burner; a primary burner gas supply passage for supplying fuel gas to the primary burner; a secondary burner gas supply passage for supplying fuel gas to the secondary burner; a primary burner gas flow rate adjusting unit interposed in the primary burner gas supply passage for adjusting the gas flow rate of the fuel gas supplied to the primary burner; a secondary burner gas flow rate adjusting unit interposed in the secondary burner gas supply passage for adjusting the gas flow rate of the fuel gas supplied to the secondary burner; and a control unit for controlling the primary burner gas flow rate adjusting unit and the secondary burner gas flow rate adjusting unit, wherein the control unit performs the following actions: switching between a secondary burner-only combustion state in which the fuel gas is supplied to the secondary burner but not to the primary burner and a simultaneous combustion state in which the fuel gas is supplied to both the secondary burner and the primary burner, in accordance with a set gas power set by a user of the gas heating cooker, and in the simultaneous combustion state, as the set gas power increases, the gas flow rate of the primary burner is increased, and the gas flow rate of the secondary burner is maintained or decreased, so as to control the maximum gas flow rate supplied to the secondary burner in the simultaneous combustion state to be smaller than the maximum gas flow rate supplied to the secondary burner in the secondary burner-only combustion state.

2. The gas heating cooker according to claim 1, further comprising an ignition unit for starting combustion at the primary and secondary burner by igniting at least the fuel gas flowing out from the secondary burner, wherein the control unit performs the following actions: controlling the gas flow rate of the secondary burner to a prescribed secondary burner combustion start flow rate and the gas flow rate of the primary burner to a prescribed primary burner combustion start flow rate at the start of combustion at the primary and secondary burner, and controlling the gas flow rate of the secondary burner to a prescribed secondary burner ignition flow rate greater than the secondary burner combustion start flow rate when igniting the secondary burner before the start of combustion at the primary and secondary burner.

3. The gas heating cooker according to claim 1 or 2, wherein in the primary and secondary burner, the primary burner is formed above the secondary burner. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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