Heating cooker

Abstract

This heating cooker HC comprising a cooker main body having an upper storage chamber 12, which has an opening 11 on top and in which a cooking container Kt can be stored through the opening, and a lower storage chamber 13, which communicates with the upper storage chamber and in which a burner Bn is disposed, is configured to uniformly heat the cooking container by equalizing the heights of hydrogen flames from a combustion plate 3 of the burner even in a state where the amount of hydrogen gas jetting from each part of the combustion plate 3 is not uniform when performing diffusion combustion of the hydrogen gas jetting from the combustion plate 3.　Introduction passages 4 for introducing secondary air are provided, the introduction passages each having: an intake port 41, which opens in an outer surface of an outer wall part of the cooker main body surrounding the lower storage chamber; and a discharge port 42, which opens in an inner surface of the outer wall part. The plurality of introduction passages are provided at intervals in the circumferential direction in a plan view.

Description

heating cooking utensils

[0001] The present invention relates to a heating cooking appliance, and more specifically to an appliance body having an upper storage chamber with an opening at the top through which a cooking container can be stored, and a lower storage chamber that communicates with the upper storage chamber and in which a burner is located.

[0002] One known example of this type of cooking appliance is described in Patent Document 1. In this appliance, a single insertion hole is formed in the peripheral wall of the appliance body surrounding the lower storage chamber, allowing the insertion of a gas burner. The gas burner includes a burner body into which a mixture (a mixture of fuel gas and primary air) is supplied via a mixing tube, and a disc-shaped combustion plate covering the upper opening of the burner body, with multiple flame holes formed in the combustion plate. After a pot (cauldron) is placed in the upper storage chamber of the appliance body through the opening, the mixture is supplied to the burner body, and the mixture ejected from the combustion plate through the flame holes is combusted to heat the pot.

[0003] In recent years, hydrogen, which does not emit carbon dioxide, has been attracting attention as an alternative fuel to hydrocarbon gases to prevent global warming. Therefore, in the cooking appliance described above, it has been considered to configure the burner to diffuse the hydrogen gas emitted from the combustion plate. However, when hydrogen gas is supplied from a single circumferential point within the burner body, the amount of hydrogen gas emitted from the portion of the combustion plate far from the hydrogen gas supply point is reduced compared to the amount of hydrogen gas emitted from the portion of the combustion plate close to the hydrogen gas supply point. Furthermore, because secondary air is supplied from a single insertion hole located in the same direction as the hydrogen gas supply to the burner body, the amount of secondary air to the portion of the combustion plate far from the hydrogen gas supply point is also reduced. As a result, the hydrogen flame generated far from the hydrogen gas supply point is not only relatively small in size, but also tilts toward the insertion hole in order to seek secondary air. As a result, the height of the hydrogen flame from the combustion plate at each point is uneven, resulting in uneven heating of the cooking vessel.

[0004] Japanese Patent Application Publication No. 11-337071

[0005] In view of the above, the present invention aims to provide a cooking appliance that can heat a cooking container evenly by making the height of the hydrogen flame from the combustion plate uniform, even when the amount of hydrogen gas ejected from each part of the combustion plate is not uniform.

[0006] In order to solve the above problems, the present invention provides a cooking appliance comprising an appliance body having an upper storage chamber with an opening at the top, through which a cooking container can be stored, and a lower storage chamber connected to the upper storage chamber and in which a burner is disposed, the burner comprising a burner body into which hydrogen gas is supplied and a combustion plate covering the upper opening of the burner body, and which diffuses and burns the hydrogen gas ejected from the combustion plate, the burner further comprising an intake port opening on the outer surface of the outer wall portion of the appliance body surrounding the lower storage chamber and an exhaust port opening on the inner surface of the outer wall portion, an introduction passage for introducing secondary air toward the hydrogen gas ejected from the combustion plate, and an exhaust port opened in the peripheral wall portion of the appliance body surrounding the upper storage chamber and for exhausting hydrogen combustion gas produced by combustion of the hydrogen gas, and the introduction passages are provided in plurality at circumferential intervals in a plan view.

[0007] According to the present invention, secondary air is introduced from multiple locations around the circumference. In areas of the combustion plate where a relatively small amount of hydrogen gas is ejected, a relatively large amount of secondary air is introduced through the outlet, allowing the hydrogen flame to extend above the secondary air. On the other hand, in areas of the combustion plate where a relatively large amount of hydrogen gas is ejected, a relatively small amount of secondary air is introduced through the outlet, allowing the hydrogen flame to tilt toward the outlet. This allows the height of the hydrogen flame from the combustion plate to be uniform in each area of ​​the combustion plate. Thus, by adopting a configuration in which secondary air is introduced from multiple locations around the circumference and appropriately setting the amount of secondary air introduced from each location around the circumference, the present invention allows the height of the hydrogen flame from the combustion plate to be uniform and the cooking vessel to be heated evenly, even when the amount of hydrogen gas ejected from each area of ​​the combustion plate is not uniform.

[0008] In addition, in the present invention, it is preferable that the combustion plate is divided into a plurality of combustion zones in the circumferential direction, and that the inner surface area of ​​the outer wall portion that includes a line connecting the circumferential ends of the outer periphery of these divided combustion zones when projected in the radial direction of the burner is defined as the outlet-port forming area, and that at least one outlet port is located in the outlet-port forming area. This is advantageous because it is possible to further reduce uneven heating of the cooking utensil by adjusting the amount of secondary air for each of the divided combustion zones.

[0009] Furthermore, in the present invention, downwardly projecting legs may be provided on the bottom surface of the appliance body, and the outer surface of the outer wall portion where the air intake opens may be used as the bottom surface of the appliance body. In this way, when the cooking appliance is installed, the air intake of the introduction passage is not directly visible and is therefore less noticeable, thereby improving the design.

[0010] In addition, in the present invention, it is preferable to provide an adjusting means for adjusting the amount of secondary air introduced through the introduction passage, which is advantageous because it makes it possible to adjust the amount of secondary air supplied to the hydrogen gas ejected from the combustion plate in accordance with variations in the manufacturing process of the cooking appliance and the conditions under which the cooking appliance is installed and used.

[0011] 1 is a perspective view showing a cooking utensil for heating according to an embodiment of the present invention with the cooking utensil removed. A cross-sectional view taken along line II-II in FIG. 1. A partially enlarged cross-sectional view of FIG. 2. A cross-sectional view taken along line IV-IV in FIG. 2. (a) and (b) are diagrams illustrating an area where an air outlet is formed in an outer wall portion of the utensil body. A cross-sectional view taken along line VI-VI in FIG. 2. A perspective view of a cooking utensil for heating according to a modified example, as seen from the bottom side. A cross-sectional view taken along line VIII-VIII in FIG. 7.

[0012] Hereinafter, with reference to the drawings, an embodiment of the cooking appliance HC will be described using a rice cooker in which rice and water are stored as a rice cooker kettle Kt as an example of the cooking appliance. Note that the "hydrogen" referred to in this invention is not limited to pure hydrogen, but also includes, for example, the case where a small amount of odorant is added to impart a flavor.

[0013] 1 and 2, the cooking appliance HC of this embodiment includes a rectangular parallelepiped appliance body 1. The appliance body 1 has an upper storage chamber 12 with an opening 11 at its top through which a rice cooker Kt can be stored, and a lower storage chamber 13 that communicates with the upper storage chamber 12 and in which a burner Bn (described below) for heating the rice cooker Kt is disposed. A bottom wall portion 13a, which is one of the exterior walls of the appliance body 1 that surrounds the lower storage chamber 13, and a peripheral wall portion 13b, which is the other exterior wall portion of the appliance body 1 that surrounds the lower storage chamber 13, extend below the bottom wall portion 13a, so that the appliance body 1 is raised above the floor on which it is placed. An air intake 14a is formed in the peripheral wall portion 13b, which is located below the bottom wall portion 13a, and an air intake 14b is also formed in the bottom wall portion 13a. The peripheral wall portion 13b located below the bottom wall portion 13a constitutes a leg portion Lp that is provided on the bottom surface of the device body 1 and protrudes downward.

[0014] The top surface of the appliance body 1 has an annular protruding wall 15 that forms part of the peripheral wall of the appliance body 1 surrounding the upper storage chamber 12 and defines the opening 11. When the rice cooker Kt is inserted from above through the opening 11 of the appliance body 1, the flange Kf that protrudes radially from the outer periphery of the rice cooker Kt rests on the upper surface of the protruding wall 15, supporting the rice cooker Kt with the portion of the rice cooker Kt below the flange Kf housed within the upper storage chamber 12. The protruding wall 15 has multiple exhaust ports 16 spaced apart circumferentially, through which hydrogen combustion gases produced by the combustion of hydrogen gas are exhausted. During cooking, a lid Kd is placed on the top opening of the rice cooker Kt.

[0015] 3 to 6, the burner Bn disposed in the lower storage chamber 13 includes a burner body 2 into which hydrogen gas is supplied and a combustion plate 3 covering the upper opening of the burner body 2. The burner body 2 includes an annular base plate 21 having an opening 21a in the center, an inner cylinder 22 extending upward from the inner peripheral edge of the base plate 21, and an outer cylinder 23 extending upward from the outer peripheral edge of the base plate 21. The burner body 2 is mounted on the inner surface (upper surface) of the bottom wall 13a via support legs 24, 24 provided on the underside of the base plate 21. The outer cylinder 23 is provided with a bulging portion 23a bulging radially outward at one location along the circumferential direction, and a connecting pipe 25 is connected to the bulging portion 23a in the radial direction. A gas pipe 27 having a gas nozzle 26 at its tip is connected to the connecting pipe 25. Although not specifically shown or described, a valve such as an electromagnetic valve or a gas cock is provided in the gas pipe 27, and hydrogen gas is supplied via the valve to the space 2a in the burner body 2 defined between the inner cylindrical portion 22 and the outer cylindrical portion 23. Since known components can be used as these components necessary for combustion in the burner Bn, further description will be omitted.

[0016] The combustion plate 3 has an annular main body 31 having a large number of flame holes 31a formed therein and blocking the upper side of the space 2a, and a partition plate 33 mounted on the upper surface of the main body 31 and dividing the combustion plate 3 into a plurality of combustion zones 32 in the circumferential direction. The partition plate 33 has an inner annular plate portion 33a secured to the upper surface of the inner cylindrical portion 22 with screws, with the inner peripheral edge of the main body 31 sandwiched between the inner annular plate portion 33a and an annular inner packing 34a placed on the upper surface of the inner cylindrical portion 22; an outer annular plate portion 33b secured to the upper surface of the outer cylindrical portion 23 with the outer peripheral edge of the main body 31 sandwiched between the inner annular plate portion 33a and an annular outer packing 34b placed on the upper surface of the outer cylindrical portion 23; and a beam plate portion 33c radially bridging the inner annular plate portion 33a and the outer annular plate portion 33b. In this embodiment, the beam plate portions 33c are arranged at 90-degree intervals in the circumferential direction, and the four openings defined by the inner annular plate portion 33a, the outer annular plate portion 33b, and the beam plate portion 33c each constitute a combustion region 32 of the combustion plate 3.

[0017] The hydrogen flame generated by the combustion of hydrogen gas is virtually invisible because it does not contain any active species that emit chemiluminescence in the visible light range. Therefore, a flame reaction agent can be applied to the upper surface of the main body 31 of the combustion plate 3 or the upper surface of the partition plate 33. In this case, for example, a known heat-resistant paint is prepared, and a granular flame reaction agent, for example, is added to the paint at a predetermined weight ratio, and the paint containing the flame reaction agent is applied to the surface. There are no particular limitations on the flame reaction agent, as long as it does not pose a hygienic problem and emits chemiluminescence in the visible light range. For example, compounds such as sodium chloride (yellow), sodium carbonate (yellow), and potassium chloride (reddish purple) can be used. This allows the hydrogen flame to be confirmed by reacting with the flame reaction agent, which causes a flame reaction.

[0018] The peripheral wall portion 13b surrounding the lower storage chamber 13 of the appliance body 1 is provided with a plurality of inlet passages 4 spaced apart in the circumferential direction in a plan view, for introducing secondary air toward the hydrogen gas ejected from the combustion plate 3 through the flame holes 31a. In this embodiment, four inlet passages 4 extending radially are provided, one for each combustion zone 32. Each inlet passage 4 has an intake port 41 opening on the outer surface 131 of the peripheral wall portion 13b and an outlet port 42 opening on the inner surface 132 of the peripheral wall portion 13b. As shown in FIG. 5( a), when a line Vl connecting both circumferential ends of the outer peripheral edge of the combustion zone 32 is projected in the radial direction of the burner Bn, the inner surface region of the peripheral wall portion 13b that includes the line Vl is defined as an outlet port forming region 42a, and at least one outlet port 42 is located in the outlet port forming region 42a.

[0019] The contour of the outlet-forming region 42a is not particularly limited as long as it can supply secondary air evenly to the hydrogen gas ejected from each combustion region 32 while minimizing the penetration of the hydrogen flames generated in each combustion region 32 beneath the burner Bn. In this embodiment, as shown in FIG. 5(b), the outlet-forming region 42a has a rectangular contour in side view, with its upper edge having a length equal to or greater than line Vl and positioned above the combustion plate 3, and both sides positioned on extensions of the beam plate portion 33c, with their lower ends reaching the bottom wall portion 13a, with the inner surface of the bottom wall portion 13a forming the lower edge. A single outlet 42 is formed in the outlet-forming region 42a. The intake port 41 has an opening area equal to that of the outlet 42. Although the description will be given taking an example in which a single outlet 42 is formed in the outlet-forming region 42a, for example, a plurality of outlets 42 with the same opening area may be formed in the outlet-forming region 42a so as to be aligned, for example, in the vertical and horizontal directions, and in this case, the introduction passage 4 may also be divided into a plurality of passages. On the other hand, a plurality of outlets 42 with different opening areas may be formed in the combustion region 32 corresponding to the outlet-forming region 42a so as to divide the combustion region 32 into a portion where the amount of introduced secondary air is large and a portion where the amount of introduced secondary air is small.

[0020] A pair of guide rails 5, 5 extending vertically are provided on the exterior of the appliance body 1, positioned on both sides of the air intake 41 (see FIG. 1 ). A plate-shaped opening / closing door 6, which increases or decreases the opening area of ​​the air intake 41, is slidably engaged with the guide rails 5, 5 in the vertical direction, and the opening / closing door 6 can be positioned and held by a locking device 7. In this embodiment, the opening / closing door 6 constitutes an adjustment means for adjusting the amount of secondary air introduced into the lower storage chamber 13 by increasing or decreasing the opening area of ​​the air intake 41. The opening / closing door 6 is made of a heat-resistant, light-transmitting material such as glass so that the interior of the lower storage chamber 13, where the burner Bn is located, can be viewed, and a handle 61 is provided on its upper edge. The locking device 7 is composed of a support 71 and two locking pins 72 protruding perpendicularly from the support 71. A plurality of through holes 62 are formed on both sides of the door 6 in the thickness direction at equal intervals in the vertical direction, and a plurality of fitting recesses 63 into which locking pins 72 fit are formed in the outer surface of the appliance body 1 at the same intervals in the vertical direction as the through holes 62, corresponding to the through holes 62. The door 6 is then moved up or down via the handle 61 depending on the amount of secondary air to be adjusted, and the locking pins 72 are fitted into the fitting recesses 63 through the through holes 62, thereby locking the door 6.

[0021] A control box Cb, which houses a control board (not shown) that receives power from, for example, a battery and controls the operation of the burner Bn, is provided on the outer surface of the appliance body 1. A mounting plate 28 is provided on the bulging portion 23a of the outer cylindrical portion 23, and a pair of rod-shaped electrodes 8a, 8b are attached to the mounting plate 28. When a valve installed in the gas pipe 27 is opened, hydrogen gas is supplied to the space 2a within the burner body 2, and the hydrogen gas is ejected from the combustion plate 3 through the flame holes 31a. Secondary air is also introduced through the respective introduction passages 4 corresponding to the combustion zone 32. Secondary air is then introduced through the air intakes 14a, 14b through the inner space of the inner cylindrical portion 22. A high voltage is applied between the pair of rod-shaped electrodes 8a, 8b by an igniter (not shown) controlled by the control board, and the resulting pyrotechnic discharge ignites the hydrogen gas, causing it to diffuse and burn. As a result, the bottom surface of the rice cooker Kt is heated by the hydrogen flames generated in each combustion zone 32, and the rice cooker Kt is heated by the hydrogen combustion gas produced by the combustion of the hydrogen gas as it is exhausted along the outer peripheral wall of the rice cooker Kt to the exhaust port 16. In this embodiment, as shown in Figure 6, the exhaust port 16 is formed to straddle the combustion zones 32 adjacent to each other in a plan view so that the hydrogen combustion gas flows evenly around the rice cooker Kt.

[0022] When hydrogen gas is supplied to the space 2a in the burner body 2 from a single connecting pipe 25 in the circumferential direction, the amount of hydrogen gas ejected from the combustion area 32 of the combustion plate 3 farther from the connecting pipe 25 (hereinafter referred to as the "combustion area 32b") is smaller than the amount of hydrogen gas ejected from the combustion area 32 close to the connection point of the connecting pipe 25 (hereinafter referred to as the "combustion area 32a"). Therefore, in the introduction passage 4 corresponding to the combustion area 32b, the position of the opening door 6 relative to the intake port 41 is appropriately adjusted to increase the opening area of ​​the intake port 41. This increases the amount of secondary air introduced toward the hydrogen gas ejected from the combustion area 32b, allowing the hydrogen flame to extend above the secondary air. Meanwhile, in the introduction passage 4 corresponding to the combustion area 32a, the position of the opening door 6 relative to the intake port 41 is appropriately adjusted to decrease the opening area of ​​the intake port 41. This reduces the amount of secondary air introduced toward the hydrogen gas, allowing the hydrogen flame to tilt toward the discharge port 42. As a result, the height of the hydrogen flame from the combustion plate 3 can be made uniform in each combustion region 32 .

[0023] According to the above embodiment, the amount of secondary air can be adjusted for each combustion zone 32, making the height of the hydrogen flame in each combustion zone 32 uniform, thereby enabling the burner Bn to heat the bottom of the rice cooker Kt evenly. Moreover, because the position of the door 6 relative to the intake port 41 can be adjusted as needed, even if the amount of hydrogen gas ejected from each combustion zone 32 of the combustion plate 3 changes depending on variations in the manufacturing process of the cooking appliance HC or the conditions under which the cooking appliance HC is installed and used, the amount of secondary air can be further adjusted to accommodate these changes, which is advantageous.

[0024] Although the present invention has been described above as an embodiment, it is not limited thereto. For example, in the above embodiment, four introduction passages 4 are provided corresponding to each of the combustion zones 32 divided into four circumferentially. However, the number of divided combustion zones 32 and the number of introduction passages 4 can be set arbitrarily. Alternatively, the amount of hydrogen gas ejected from each combustion zone 32 when hydrogen gas is supplied from the connecting pipe 25 to the space 2a in the burner body 2 can be calculated in advance, and the amount of secondary air to be introduced can be experimentally determined in advance based on this calculated amount of hydrogen gas. The passage area of ​​the introduction passage 4 can then be preset in advance in accordance with the experimentally determined amount of secondary air during the design stage of the cooking appliance HC, thereby making the height of the hydrogen flame uniform.

[0025] In the above embodiment, the air intake 41 is provided in the peripheral wall portion 13b, but this is not limiting. Referring to Figures 7 and 8, in a modified example, downwardly protruding legs Lp are provided at the four corners of the bottom surface of the bottom wall portion 13a of the appliance body 1, i.e., the bottom surface of the appliance body 1. A plurality of air intakes 41 for the introduction passage 4 are provided on the bottom surface of the appliance body 1. This allows the air intakes 41 for the introduction passage 4 to be inconspicuous and not directly visible when the cooking appliance HC is installed, thereby improving the design.

[0026] Furthermore, in the above embodiment, the cooking vessel, i.e., a rice cooker Kt, is supported by seating its flange Kf on the upper surface of the protruding wall 15. However, any shape is acceptable as long as it can support a cooking vessel stored in the upper storage chamber 12 through the opening 11. For example, although not specifically illustrated or described, a mesh-like stand or trivet may be installed in the upper storage chamber 12 to support cooking utensils. Furthermore, in the above embodiment, the combustion plate 3 of the burner Bn is described as having an annular main body 31 with multiple flame holes 31a, but this is not limited thereto. For example, the combustion plate 3 can be formed of a sintered sheet formed by sintering a laminate of metal fibers or metal beads. Furthermore, in the above embodiment, the appliance body 1 is described as having a rectangular parallelepiped shape, but this is not limited thereto. For example, the appliance body 1 may be cylindrical. In this case, the opening and closing door 6 may be shaped to fit the outer surface of the appliance body 1.

[0027] HC...heating cooking appliance, Kt...kettle (cooking container), 1...apparatus body, 11...opening, 12...upper storage chamber, 13...lower storage chamber, 13a...bottom wall portion (outer wall portion of the appliance body surrounding the lower storage chamber), 13b...peripheral wall portion (outer wall portion of the appliance body surrounding the lower storage chamber), 16...exhaust port, Bn...burner, 2...burner body, 3...combustion plate, 32...combustion area, 4...introduction passage, Lp...leg portion, 41...intake port, 42...exhaust port, 42a...exhaust port forming area, 6...opening / closing door (adjustment means).

Claims

1. A cooking appliance comprising an appliance body having an upper storage chamber having an opening at the top and capable of storing a cooking container through said opening, and a lower storage chamber communicating with said upper storage chamber and in which a burner is disposed, wherein the burner comprises a burner body into which hydrogen gas is supplied and a combustion plate covering the upper opening of the burner body, and diffuses and burns the hydrogen gas ejected from the combustion plate, further comprising an intake port opening into the outer surface of an outer wall portion of the appliance body surrounding the lower storage chamber and an exhaust port opening into the inner surface of the outer wall portion, an introduction passage for introducing secondary air toward the hydrogen gas ejected from the combustion plate, and an exhaust port opened in the peripheral wall portion of the appliance body surrounding the upper storage chamber and for exhausting hydrogen combustion gas generated by combustion of the hydrogen gas, wherein a plurality of the introduction passages are provided at intervals in the circumferential direction when viewed in a plane.

2. A cooking appliance as described in claim 1, characterized in that the combustion plate is partitioned circumferentially into a plurality of combustion zones, and when a line connecting both circumferential ends of the outer periphery of these partitioned combustion zones is projected in the radial direction of the burner, the inner surface area of ​​the outer wall portion that includes the line is defined as an exhaust port forming area, and at least one exhaust port is present in the exhaust port forming area.

3. A cooking utensil as claimed in claim 2, characterized in that the bottom surface of the utensil body is provided with legs that protrude downward, and the outer surface of the outer wall portion where the air intake is opened forms the bottom surface of the utensil body.

4. A cooking device according to any one of claims 1 to 3, further comprising an adjusting means for adjusting the amount of secondary air introduced through the introduction passage.

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