Cooking instrument

Abstract

To structure a cooking instrument HC which includes an instrument body 1 having an upper storage chamber 12 having an opening 11 in the upper part and capable of storing a cooking container Kt through the opening and having a lower storage chamber 13 for communicating with the upper storage chamber and for being arranged with a burner Bn, and which is made to suppress as much as possible the flow-out to the outside of the instrument body, in the case of diffusion combustion of hydrogen gas squirting from the combustion plate 3 of the burner, even if the hydrogen flame propagates to an introduction passage 4 for introducing secondary air.SOLUTION: A flame shield part 6 is provided which shields flame when hydrogen flame propagates into an introduction passage, while aeration of secondary air into the introduction passage is allowed.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] As an example of this type of cooking utensil, the one described in Patent Document 1 is known. In this utensil, a single insertion hole that allows the insertion of a gas burner is formed in the peripheral wall of the utensil body surrounding the lower storage chamber. 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 disk-shaped combustion plate that covers the upper opening of the burner body, and a number of flame holes are formed in the combustion plate. Then, after a pot (kettle) as a cooking utensil is stored in the upper storage chamber of the utensil body through the opening, the mixture is supplied to the burner body, and the pot is heated by burning the mixture that is ejected from the combustion plate through the flame holes.

[0003] In recent years, hydrogen, which does not emit carbon dioxide, has been attracting attention as an alternative fuel to hydrocarbon gas in order to prevent global warming. In the above-mentioned conventional cooking appliance, it is possible to configure the burner to diffuse and burn hydrogen gas ejected from the combustion plate. In this case, secondary air is mainly supplied from the insertion hole. The above-mentioned cooking appliance is equipped with an ignition means for igniting the burner, but it is known that the ignition delay of the burner may occur due to deterioration of the ignition means over time. When the ignition delay occurs, the hydrogen flame may propagate to the insertion hole in search of secondary air and overflow outside the appliance. Such overflow causes discomfort to the user of the appliance. The overflow of the hydrogen flame may also occur depending on the conditions when the cooking appliance is installed and used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-337071 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an object of the present invention is to provide a cooking utensil that can minimize the overflow of hydrogen flames outside the utensil even if the hydrogen flame propagates through an inlet passage for introducing secondary air when diffusively burning hydrogen gas. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a cooking appliance comprising an appliance body having an upper storage chamber having an opening at the top, through which a cooking container can be stored, and a lower storage chamber communicating with 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 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 for exhausting hydrogen combustion gas generated by combustion of the hydrogen gas, the introduction passage being provided with a flame-shielding section which allows the secondary air to pass while blocking the hydrogen flame when it propagates into the introduction passage.

[0007] According to the present invention, even if a hydrogen flame propagates into the introduction passage in search of secondary air due to ignition delay when hydrogen is diffused and burned, or due to the conditions when the appliance is installed and used, the hydrogen flame is blocked by a flame-blocking section provided in the introduction passage, thereby preventing the hydrogen flame from overflowing outside the appliance as much as possible.

[0008] In the present invention, when the upper edge of the discharge port is located above the combustion plate, the flame blocking portion can be configured as an extension member extending downward from the upper wall surface of the introduction passage, with the lower end of the extension member located below the combustion plate portion, or the upper wall surface of the introduction passage is provided with an inclined surface that slopes downward from the discharge port side to the intake port side, and this inclined surface constitutes the flame blocking portion. According to these aspects, even if the hydrogen flame propagates to the introduction passage in search of secondary air, it is possible to realize a configuration that reliably blocks the hydrogen flame within the introduction passage while not normally impeding the introduction of secondary air to the hydrogen flame.

[0009] Furthermore, when the flame-blocking portion is formed of an extension member, it is preferable to form a number of small holes penetrating the extension member from the intake port side to the exhaust port side. In this way, when the hydrogen flame propagates into the introduction passage, the small holes quench the hydrogen flame, thereby further preventing it from overflowing outside the device. The diameter of the small holes is preferably set to, for example, 0.6 mm or less, which is the quenching distance. In addition, a bent portion extending toward the lower storage chamber side may be provided at the lower end of the extension member. This is advantageous in that it can further enhance the effect of blocking the hydrogen flame at the flame-blocking portion.

[0010] In addition, the present invention can employ a configuration in which a plurality of introduction passages are provided at intervals in the circumferential direction in a plan view. In this way, secondary air is introduced from a plurality of locations in the circumferential direction, and by appropriately setting the amount of secondary air introduced from each location in the circumferential direction, the height of the hydrogen flame from the combustion plate can be made uniform and the cooking vessel can be heated evenly evenly, even if the amount of hydrogen gas ejected from each part in the circumferential direction of the combustion plate is not uniform.

[0011] Furthermore, in the present invention, a detection means for detecting a hydrogen flame may be provided on the lower storage chamber side of the introduction passage where the flame blocking portion is disposed, and when the detection means detects a hydrogen flame, an alarm is given. In this way, it is possible to detect the occurrence of a burner ignition delay due to deterioration over time, and by notifying this, the need for maintenance can be notified to the user of the appliance. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a cooking utensil for heating according to an embodiment of the present invention with the cooking utensil removed; [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view of a portion of FIG. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 2 . [Diagram 5] 13A and 13B are diagrams illustrating a flame blocking portion according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, with reference to the drawings, an embodiment of the cooking utensil HC will be described using a rice cooker in which rice and water are stored as a cooking utensil. Note that the "hydrogen" in the present invention is not limited to pure hydrogen, and also includes, for example, a case where a small amount of odorant is added to give a smell.

[0014] 1 and 2, the cooking utensil HC of this embodiment includes a rectangular parallelepiped utensil body 1. The utensil body 1 has an upper opening 11 at the top, an upper storage chamber 12 in which a rice cooker Kt can be stored through the opening 11, and a lower storage chamber 13 in which a burner Bn (described later) for heating the rice cooker Kt is arranged and communicates with the upper storage chamber 12. A bottom wall portion 13a, which is one of the outer wall portions of the utensil body 1 surrounding the lower storage chamber 13, is raised above the floor surface on which the utensil body 1 is placed, as a peripheral wall portion 13b, which is the other outer wall portion of the utensil body 1 surrounding the lower storage chamber 13, extends below the bottom wall portion 13a. An air intake 14a is formed in the peripheral wall portion 13b 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 main body 1 and protrudes downward.

[0015] The upper surface of the appliance body 1 has an annular protruding wall 15 which is a 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 which protrudes radially from the outer circumferential surface of the rice cooker Kt is seated on the upper surface of the protruding wall 15, and the rice cooker Kt is supported in a state where the part of the rice cooker Kt located below the flange Kf is stored in the upper storage chamber 12. A plurality of exhaust ports 16 are formed in the protruding wall 15 at intervals in the circumferential direction, and hydrogen combustion gas generated by the combustion of hydrogen gas is exhausted. In addition, a lid kd is placed on the upper opening of the rice cooker Kt during cooking.

[0016] 3 and 4, the burner Bn arranged in the lower storage chamber 13 includes a burner body 2 to which hydrogen gas is supplied and a combustion plate 3 that covers the upper opening of the burner body 2. The burner body 2 includes an annular base plate portion 21 having an opening 21a in the center, an inner cylinder portion 22 that stands upward from the inner peripheral edge of the base plate portion 21, and an outer cylinder portion 23 that stands upward from the outer peripheral edge of the base plate portion 21. The burner body 2 is installed on the inner surface (upper surface) of the bottom wall portion 13a via support legs 24, 24 provided on the lower surface of the base plate portion 21. In addition, a bulging portion 23a that bulges outward in the radial direction is provided at one location in the circumferential direction of the outer cylinder portion 23, and a connecting pipe 25 is connected to the bulging portion 23a from 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 through 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 parts can be used as these parts necessary for combustion in the burner Bn, further description will be omitted.

[0017] The combustion plate 3 has an annular main body portion 31 in which a large number of flame holes 31a are formed and which blocks the upper side of the space 2a, and a partition plate portion 33 which is installed on the upper surface of the main body portion 31 and which partitions the combustion plate 3 into a plurality of combustion regions 32 in the circumferential direction. The partition plate portion 33 has an inner annular plate portion 33a which is screwed to the upper surface of the inner cylindrical portion 22 with the inner peripheral edge of the main body portion 31 sandwiched between it and an annular inner packing 34a placed on the upper surface of the inner cylindrical portion 22, an outer annular plate portion 33b which is screwed to the upper surface of the outer cylindrical portion 23 with the outer peripheral edge of the main body portion 31 sandwiched between it and an annular outer packing 34b placed on the upper surface of the outer cylindrical portion 23, and a beam plate portion 33c which radially bridges the inner annular plate portion 33a and the outer annular plate portion 33b. In this embodiment, the beam plate portions 33c are provided 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.

[0018] However, the hydrogen flame generated by the combustion of hydrogen gas is hardly visible because there is no active species accompanied by chemiluminescence in the visible light region. Therefore, a flame color reaction agent can be applied to the upper surface of the main body part 31 of the combustion plate 3 or the upper surface of the partition plate part 33. In such a case, for example, a known heat-resistant paint is prepared, and a granular flame color reaction agent is added to this paint at a predetermined weight ratio, and the paint to which the flame color reaction agent has been added is applied to the surface. There is no particular restriction on the flame color reaction agent as long as it does not cause hygienic problems and expresses chemiluminescence in the visible light region, and for example, compounds such as sodium chloride (yellow), sodium carbonate (yellow), and potassium chloride (reddish purple) can be used. As a result, the hydrogen flame reacts with the flame color reaction agent to cause a flame color reaction, making it possible to confirm the hydrogen flame.

[0019] In the peripheral wall portion 13b surrounding the lower storage chamber 13 of the appliance body 1, a plurality of introduction passages 4 for introducing secondary air toward the hydrogen gas ejected from the combustion plate 3 through the flame holes 31a are provided at intervals in the circumferential direction in a plan view. In this embodiment, four introduction passages 4 extending in the radial direction are provided corresponding to each combustion region 32. The introduction passages 4 have an intake port 41 opening on the outer surface 131 of the peripheral wall portion 13b and an exhaust port 42 opening on the inner surface 132 of the peripheral wall portion 13b. The outline of the exhaust port 42 is not particularly limited as long as it can supply secondary air evenly to the hydrogen gas ejected from each combustion region 32 while suppressing the hydrogen flame generated in each combustion region 32 from penetrating below the burner Bn as much as possible. In this embodiment, the outlet 42 has a rectangular outline in a side view, and an upper side 421 constituting the upper edge has a length equal to or greater than the line Vl connecting both circumferential ends of the outer periphery of the combustion region 32 and is located above the combustion plate 3, and both side edges 422 are located on extensions extending from the beam plate portion 33c, and their lower ends reach the bottom wall portion 13a, with the inner surface of the bottom wall portion 13a forming the lower side. The intake port 41 is set to have an opening area equal to that of the outlet 42.

[0020] On the outer surface of the device body 1, a control box Cb is provided that incorporates a control board (not shown) that receives power from a battery, for example, and controls the operation of the burner Bn. A mounting plate 28 is provided on the bulging portion 23a of the outer cylinder 23, and a pair of rod-shaped electrodes 5a, 5b are attached to the mounting plate 28. When a valve interposed in the gas pipe 27 is opened, hydrogen gas is supplied to the space 2a in the burner body 2, and the hydrogen gas is ejected from the combustion plate 3 through the flame hole 31a, and secondary air is introduced from each introduction passage 4 corresponding to the combustion region 32. Furthermore, secondary air is introduced through the air intakes 14a, 14b through the inner space of the inner cylinder 22. A high voltage is applied between the pair of rod-shaped electrodes 5a, 5b from an igniter (not shown) controlled by the control board, and the hydrogen gas is ignited by the pyrotechnic discharge generated at that time, and the hydrogen gas is diffused and burned. As a result, the bottom surface of the rice cooker Kt is heated by the hydrogen flames generated in each combustion region 32, and the rice cooker Kt is heated by the hydrogen combustion gas generated by the combustion of the hydrogen gas while it is exhausted to the exhaust port 16 along the outer peripheral wall of the rice cooker Kt. Although not specifically shown or described, the exhaust port 16 is formed to straddle the adjacent combustion regions 32 in a plan view so that the hydrogen combustion gas flows evenly around the rice cooker Kt.

[0021] Here, when applying a high voltage between the pair of rod-shaped electrodes 5a, 5b to ignite as described above, ignition delay of the burner Bn may occur due to aging or the like. If the upper side 421 of the discharge port 42 is located above the combustion plate 3, when ignition delay occurs, the hydrogen flame may propagate to the introduction passage 4 in search of secondary air and overflow outside the appliance body 1. Such overflow may also occur depending on the situation when the appliance body 1 is installed and used. Therefore, in this embodiment, a flame-blocking section 6 is provided in each introduction passage 4, which allows the secondary air to pass through while blocking the hydrogen flame when it propagates into the introduction passage 4.

[0022] The flame blocking portion 6 is composed of a plate-shaped extension member 61 that is positioned between the discharge port 42 and the intake port 41 and extends downward from the upper wall surface of the introduction passage 4. The extension member 61 has a width equal to that of the introduction passage 4, and the lower end of the extension member 61 extends downward from the upper surface of the combustion plate 3, and a gap Gp that allows secondary air to pass is formed between the extension member 61 and the inner surface 132 of the bottom wall portion 13a. In order to improve the flame blocking function of the hydrogen flame, it is preferable to provide the extension member 61 at a location close to the intake port 41 of the introduction passage 4 away from the discharge port 42. In addition, the extension member 61 is formed with a large number of small holes 62 that penetrate from the intake port 41 side to the discharge port 42 side. The hole diameter of the small holes 62 is preferably set to 0.6 mm or less, which is the flame quenching distance. Furthermore, a bent portion 63 that is bent toward the lower storage chamber 13 side is provided at the lower end of the extension member 61.

[0023] According to the above embodiment, even if an ignition delay occurs and the hydrogen flame propagates to the introduction passage 4 in search of secondary air, the hydrogen flame is blocked by the extension member 61, so that the overflow of the hydrogen flame outside the device body 1 can be suppressed as much as possible, and the introduction of secondary air to the hydrogen flame can be permitted normally. In this case, not only can the bent portion 63 further enhance the effect of blocking the hydrogen flame, but the small hole 62 can extinguish the hydrogen flame, so that the overflow of the hydrogen flame outside the device body 1 can be further suppressed.

[0024] Here, as shown in Fig. 4, when hydrogen gas is supplied to the space 2a in the burner body 2 from one connecting pipe 25 in the circumferential direction, the amount of hydrogen gas ejected from the combustion area 32 of the combustion plate 3 away from the connecting pipe 25 (hereinafter referred to as "combustion area 32b") is reduced compared to 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 "combustion area 32a"). In such a case, in the introduction passage 4 corresponding to the combustion area 32b, the height of the extension member 61 is changed to increase the gap Gp between the lower end of the extension member 61 and the inner surface 132 of the bottom wall portion 13a within a range that does not impair the function of suppressing the overflow of the hydrogen flame. As a result, the amount of secondary air introduced toward the hydrogen gas ejected from the combustion area 32b increases, and the hydrogen flame can be extended to stand above the secondary air in search of it.

[0025] On the other hand, in the introduction passage 4 corresponding to the combustion region 32a, the gap Gp between the lower end of the extension member 61 and the inner surface 132 of the bottom wall portion 13a is made small. This reduces the amount of secondary air introduced toward the hydrogen gas, allowing the hydrogen flame to be tilted toward the exhaust 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. By adjusting the amount of secondary air for each combustion region 32 in this way to make the height of the hydrogen flame in each combustion region 32 uniform, the bottom of the rice cooker Kt can be heated evenly by the burner Bn. It is also possible to calculate in advance the amount of hydrogen gas ejected from each combustion region 32 when hydrogen gas is supplied from the connecting pipe 25 to the space 2a in the burner body 2, experimentally determine the amount of secondary air to be introduced according to the calculated amount of hydrogen gas, and set the passage area of ​​the introduction passage 4 in advance according to the experimentally determined amount of secondary air at the design stage of the cooking appliance HC to make the height of the hydrogen flame uniform.

[0026] In the meantime, in a situation where ignition delay occurs, it is desirable to inform the user of the appliance of the need for maintenance. In this embodiment, a detection means 7 for detecting a hydrogen flame is provided on the lower storage chamber 13 side of the introduction passage 4 where the flame-shielding part 6 is arranged. The detection means 7 is composed of a thermocouple inserted in the extension member 61. When the detection means 7 detects a hydrogen flame, this is input to the control board, and the necessity of maintenance is notified by voice via the speaker Sk provided in the control box Cb. It is also possible to provide a display (not shown) in the control box Cb to notify the necessity of maintenance as an image. This makes it possible to detect the occurrence of ignition delay in the burner Bn due to aging or the like, and by notifying this, it is possible to inform the user of the necessity of maintenance.

[0027] Although the embodiment of the present invention has been described above, the present invention is not limited thereto. In the above embodiment, the plate-shaped extension member 61 is provided in the introduction passage 4, but the form is not limited as long as the hydrogen flame propagating in the introduction passage 4 can be blocked while allowing the secondary air to pass. For example, as shown in FIG. 5(a), the upper wall surface of the introduction passage 4 can be provided with an inclined surface 43 that slopes downward from the discharge port 42 side to the intake port 41 side, and the inclined surface 43 can form the flame blocking portion 6. In the above embodiment, the gap Gp that allows the secondary air to pass between the lower end of the extension member 61 and the inner surface 132 of the bottom wall portion 13a is provided, but as shown in FIG. 5(b), the lower end of the extension member 61 can be extended to the inner surface 132 of the bottom wall portion 13a, and a large number of air holes 64 larger in diameter than the small holes 62 can be provided on the lower end side of the extension member 61, so that the secondary air can be allowed to pass through the air holes 64. Although not specifically illustrated or described, only the upper wall of the introduction passage 4 may be extended to the outside of the instrument body 1, and an extension member 61 may be provided at the tip of this extended upper wall.

[0028] In the above embodiment, the rice cooker Kt as a cooking vessel is supported by seating its flange Kf on the upper surface of the protruding wall 15, but the shape is not important as long as the cooking vessel stored in the upper storage chamber 12 through the opening 11 can be supported. For example, although not shown and described, a mesh-like stand or trivet may be installed in the upper storage chamber 12 to support the cooking vessel. In the above embodiment, the combustion plate 3 of the burner Bn is provided with a ring-shaped main body 31 having a large number of flame holes 31a, but this is not limited to this. For example, the combustion plate 3 can be made of a sintered sheet obtained by sintering a laminate of metal fibers or metal beads. In the above embodiment, the appliance main body 1 is provided with a rectangular parallelepiped shape, but this is not limited to this, and the appliance main body 1 may be cylindrical, for example. [Explanation of symbols]

[0029] HC... cooking appliance, Kt... kettle (cooking container), 1... appliance 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, 4... introduction passage, 41... intake port, 42... exhaust port, 6... flame shielding portion, 61... extension member, 62... small hole, 63... bent portion, 64... inclined surface, 7... thermocouple (means for detecting hydrogen flame).

Claims

1. A cooking utensil having an appliance body including an upper storage chamber having an opening at the top, in which a cooking vessel can be stored through the opening, and a lower storage chamber communicating with the upper storage chamber and in which a burner is disposed, The burner includes a burner body into which hydrogen gas is supplied, and a combustion plate covering an upper surface opening of the burner body, and the hydrogen gas ejected from the combustion plate is diffused and combusted, an intake passage having an intake port opening on the outer surface of an 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, for introducing secondary air toward the hydrogen gas ejected from the combustion plate; and an exhaust port opened in a peripheral wall portion of the appliance body surrounding the upper storage chamber, for exhausting hydrogen combustion gas generated by combustion of the hydrogen gas, A cooking device comprising: a flame-blocking portion provided in the introduction passage for blocking a hydrogen flame when the flame propagates within the introduction passage while allowing secondary air to pass through the introduction passage.

2. 2. The cooking device according to claim 1, wherein the upper edge of the discharge port is located above the combustion plate, The cooking device according to claim 1, wherein the flame blocking portion is constituted by an extension member extending downward from an upper wall surface of the introduction passage, and a lower end of the extension member is located below the combustion plate portion.

3. 3. The cooking device according to claim 2, wherein the extension member is formed with a large number of small holes penetrating from the intake port side to the exhaust port side.

4. 3. The cooking device according to claim 2, wherein a bent portion is provided at a lower end of the extension member, the bent portion extending toward the lower storage chamber.

5. 2. The cooking device according to claim 1, wherein the upper edge of the discharge port is located above the combustion plate, A cooking device according to claim 1, wherein an inclined surface is provided on an upper wall surface of the introduction passage, the inclined surface inclining downward from the outlet side to the inlet side, and the flame blocking portion is constituted by the inclined surface.

6. 6. The cooking device according to claim 1, wherein a plurality of the introduction passages are provided at intervals in the circumferential direction in a plan view.

7. The cooking device according to any one of claims 1 to 5, further comprising a detection means for detecting a hydrogen flame, the detection means being provided on the lower storage chamber side of the introduction passage where the flame-blocking portion is disposed, and configured to notify an alarm when a hydrogen flame is detected by the detection means.

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