Burner for heating cooker and heating cooker

Abstract

The present invention provides a burner for a heating cooker, the burner comprising a burner body (5) having a gas inflow pipe part extending vertically through a bottom wall part (51); and a burner cap (6), wherein engaging pieces (67) are suspended from the burner cap (6), and the burner body (5) is provided with engagement-receiving parts (54) to be engaged by the engaging pieces (67). In this burner, uniformity of heat distribution can be ensured, and erroneous placement of the burner cap (6) can be more easily recognized by a user. A plurality of protruding parts (55) protruding outward from the outer circumferential surface of a gas inflow pipe upper part (52b) are provided on the burner body (5) at intervals in the circumferential direction. The burner cap (6) is provided with the plurality of engaging pieces (67) that engage with the plurality of engagement-receiving parts (54), which are formed from the plurality of circumferential intervals between the protruding parts (55). Two or more kinds of protrusions having different upper surfaces are provided as the protruding parts (55). In a state in which the engaging pieces (67) are not respectively engaged with the engagement-receiving parts (54), the burner cap (6) is inclined.

Description

Burner for heating cooker and heating cooker

[0001] The present invention relates to a burner for a cooking device that heats an object to be heated that is placed on a trivet on the top plate of the cooking device, and to a cooking device equipped with this burner.

[0002] A known example of a conventional burner for a cooking appliance of this type is disclosed in Patent Document 1, which includes a burner body having a bottom wall and a gas inlet pipe extending vertically through the bottom wall, a burner cap mounted on the burner body so as to define a distribution chamber communicating with the gas inlet pipe between the burner body and the burner cap, and a nozzle for injecting fuel gas toward an inlet opening at the upstream end face of the gas inlet pipe, such that a mixture of primary air and fuel gas flowing in from the inlet is supplied to the distribution chamber from an outlet opening at the upper end face of the gas inlet pipe, which is a part of the gas inlet pipe extending above the bottom wall of the burner body. In this burner, a plurality of flame holes are provided at intervals in the circumferential direction on an outer peripheral wall of the distribution chamber extending vertically so as to surround the outer periphery of the distribution chamber between the burner body and the burner cap. In addition, a single engaging piece extending downward is hung from the part of the burner cap covering the distribution chamber, and an engaged portion with which the engaging piece engages is provided on the burner body, and the engaging piece engages with the engaged portion, thereby preventing the burner cap from rotating relative to the burner body.

[0003] In the above-mentioned conventional example, if the burner cap is incorrectly set in a phase where the engaging piece is not engaged with the engaged part, the hanging part of the engaging piece will float, causing the burner cap to tilt, making it easier for the user to recognize that the burner cap is incorrectly set. However, in this case, the gas flow from the outlet toward the flame hole located in the same direction as the engaging piece interferes with the engaging piece, reducing the gas flow rate ejected from this flame hole. As a result, the heating power is reduced only at one circumferential point in the same direction as the engaging piece, and the uniformity of the heat distribution (circumferential distribution of heating power) is impaired.

[0004] Japanese Patent Application Laid-Open No. 2012-225608

[0005] In view of the above, the present invention aims to provide a burner for a cooking device that can ensure uniform heat distribution and also makes it easier for the user to recognize if the burner cap has been set incorrectly, as well as a cooking device equipped with this burner.

[0006] In order to solve the above problems, the first invention of the present application is a burner for a cooking device that heats an object to be heated placed on a trivet on the top plate of the cooking device, the burner comprising: a burner body having a bottom wall portion and a gas inlet pipe portion extending vertically through the bottom wall portion; a burner cap placed on the burner body so as to define a distribution chamber communicating with the gas inlet pipe portion between the burner body and the burner cap; and a nozzle that injects fuel gas toward an inlet opening at an upstream end face of the gas inlet pipe portion, so that a mixture of primary air and fuel gas flowing in from the inlet opening is supplied to the distribution chamber from an outlet opening at an upper end face of the upper part of the gas inlet pipe, which is a part of the gas inlet pipe portion extending above the bottom wall portion of the burner body; and a distribution chamber outer peripheral wall portion extending vertically so as to surround the outer periphery of the distribution chamber between the burner body and the burner cap. a burner body having a plurality of protrusions projecting outward from the outer circumferential surface of the upper part of the gas inlet pipe at intervals in the circumferential direction, a burner cap having a plurality of engaging pieces extending downwardly at a portion covering the distribution chamber, the burner body having an engaged portion with which the engaging pieces engage, the engagement of the engaging pieces preventing the burner cap from rotating relative to the burner body, the burner body having a plurality of protrusions projecting outward from the outer circumferential surface of the upper part of the gas inlet pipe at intervals in the circumferential direction, the burner cap having a plurality of engaging pieces which engage with a plurality of engaged portions formed by a plurality of circumferential intervals between these protrusions, two or more types of protrusions having different upper surface heights are provided, or two or more types of engaging pieces having different vertical lengths are provided, so that the burner cap tilts when the engaging pieces are not engaged with the respective engaged portions.

[0007] According to the present invention, the heating power decreases at multiple circumferential locations in the same direction as the multiple engaging pieces. However, if the entire circumference of the burner is divided into multiple circumferential ranges each including a portion in the same direction as each engaging piece, the heating power in these multiple circumferential ranges becomes uniform, ensuring uniform heat distribution. Furthermore, if the burner cap is incorrectly set in a phase where the engaging pieces do not engage with the respective engaged portions, the burner cap will tilt, making it easier for the user to recognize that the burner cap is incorrectly set.

[0008] In addition, in the present invention, it is desirable that the circumferential intervals between the engaging pieces and the engaged parts are not uniform, but that each engaging piece can engage with a corresponding predetermined engaged part only when the burner cap is at a predetermined phase relative to the burner body. This makes it possible to uniquely determine the mounting phase of the burner cap relative to the burner body.

[0009] Furthermore, the burner for a cooking appliance of the present invention may be a burner of the type that draws in primary air by the so-called radial Venturi effect. Specifically, the burner may be a burner in which the lower part of the gas inlet pipe, which is the part of the gas inlet pipe that extends downward from the bottom wall part of the burner body, is formed straight in the vertical direction, an inlet is opened at the lower end face of the lower gas inlet pipe, which is the upstream end face of the gas inlet pipe, and an opposing plate part is provided above and opposite to the outlet opening at the upper end face of the upper gas inlet pipe, with a gap therebetween, and which diffuses the gas flow flowing out from the outlet in the radial direction and exerts the effect of drawing in primary air from the inlet (the so-called radial Venturi effect).

[0010] However, when a flame comes into contact with the trivet claws, CO is generated. Therefore, in the present invention, it is desirable to position each engagement piece in the same direction as each trivet claw. This reduces the flame power in the same direction as the engagement piece, i.e., shortens the flame, preventing the flame from coming into contact with the trivet claws.

[0011] 1 is a perspective view of a main part of a cooking device equipped with a burner for a cooking device according to an embodiment of the present invention. It is a cross-sectional side view taken along line II-II in FIG. 1. It is a cross-sectional front view taken along line III-III in FIG. 2. It is a cross-sectional plan view taken along line IV-IV in FIG. 2. (a) A perspective view of a burner cap of the burner for a cooking device according to an embodiment, as seen obliquely from below, (b) A perspective view of a burner body of the burner for a cooking device according to an embodiment, as seen obliquely from above. It is a cross-sectional plan view of a burner for a cooking device according to another embodiment, corresponding to FIG. 4.

[0012] 1 to 3 show a cooking appliance equipped with a cooking appliance burner A according to an embodiment of the present invention. The cooking appliance has a top plate 2 that covers the top surface of a cooking appliance main body 1. The top plate 2 is composed of a top plate main body 21 and an annular cover plate 22 that covers a burner opening 21a in the top plate main body 21 from above. A trivet 3 is disposed on the cover plate 22. The cooking appliance burner A, which heats an object to be heated, such as a cooking container, placed on the trivet 3, is disposed so as to be exposed above the cover plate 22. The trivet 3 has four trivet claws 32 that are erected at 90° intervals on an annular trivet frame 31.

[0013] Four radially inward recesses 22a are formed at 90° intervals on the outer periphery of the cover plate 22. The inner edge of the lower end of each trivet claw 32 engages with each recess 22a, preventing the trivet 3 from rotating. A cup-shaped burner holder 4 is attached to a base 11 fixed to the stove body 1 so that its upper end fits within the cover plate 22. The inner periphery of the cover plate 22 is fastened to a flange 41 provided on the burner holder 4 with screws 22b.

[0014] The burner A for a cooking appliance includes a burner body 5 supported by a burner holder 4 and a burner cap 6 detachably mounted on the burner body 5. The burner body 5 has a disk-shaped bottom wall 51 and a gas inlet pipe 52 extending vertically through the bottom wall 51. A lower gas inlet pipe 52a, which is the portion of the gas inlet pipe 52 extending below the bottom wall 51 of the burner body 5, is formed straight in the vertical direction. An internal passage 521 of the gas inlet pipe 52 is formed in a tapered shape, gradually decreasing in diameter from an inlet 522 opening at the lower end surface of the lower gas inlet pipe 52a (the upstream end surface of the gas inlet pipe 52) to an outlet 523 opening at the upper end surface of an upper gas inlet pipe 52b, which is the portion of the gas inlet pipe 52 extending above the bottom wall 51 of the burner body 5. The burner body 5 is also provided with a plurality of stepped ribs 53 arranged radially, which extend outward from the outer peripheral surface of the lower part 52a of the gas inlet pipe along the underside of the bottom wall part 51. The burner body 5 is supported on the burner holder 4 by these ribs 53 in a rotation-preventing state.

[0015] The cooker burner A further includes a nozzle 7 that injects fuel gas toward the inlet 522 of the gas inlet pipe 52. The nozzle 7 is attached to the downstream end of a gas supply pipe 71 that is inserted and fixed to the center of the bottom of the burner holder 4. The cooker burner A is also provided with an ignition electrode 8 and a thermocouple 9 for flame detection.

[0016] The burner cap 6 is placed on the burner body 5 so that a distribution chamber 61 communicating with the gas inlet pipe 52 is defined between the burner body 5 and the burner cap 6. A distribution chamber outer peripheral wall 62 extends vertically between the burner body 5 and the burner cap 6 to surround the distribution chamber 61. A plurality of flame holes 63 are provided at intervals in the circumferential direction on the distribution chamber outer peripheral wall 62. Small flame holding holes 64 are also provided on the distribution chamber outer peripheral wall 62, located below and between the flame holes 63. The flame holes 63 include four trivet flame holes 63A, each located at the same position as the four trivet claws 32. One of the trivet flame holes 63A also serves as an ignition flame hole facing the ignition electrode 8. The burner cap 6 also has a canopy 65 that extends outward and covers the ignition electrode 8 from above.

[0017] In this embodiment, the distribution chamber outer peripheral wall 62 is suspended from the burner cap 6, but the distribution chamber outer peripheral wall 62 may be erected from the burner body 5, or the distribution chamber outer peripheral wall 62 may be divided into two, upper and lower, with the upper half suspended from the burner cap 6 and the lower half erected from the burner body 5. In addition, in this embodiment, the flame holes 63 are formed by holes formed in the distribution chamber outer peripheral wall 62, but grooves may be formed in the distribution chamber outer peripheral wall 62 and the flame holes 63 may be formed by these grooves.

[0018] The cooker burner A further includes an opposing plate 66 located above the outlet 523 of the gas inlet pipe 52, with a gap therebetween. The gas flow flowing out from the outlet 523 diffuses radially upon contact with the opposing plate 66. This produces an effect of drawing primary air through the inlet 522 of the gas inlet pipe 52 (the so-called radial Venturi effect). The mixture of primary air and fuel gas flowing in from the inlet 522 is then supplied to the distribution chamber 61 through the outlet 523 of the gas inlet pipe 52. In this embodiment, the opposing plate 66 is integral with the burner cap 6, but it is also possible to provide the opposing plate 66 on the burner body 5 side (see, for example, JP 2011-52947 A).

[0019] 4 and 5, an engaging piece 67 extends downward from the portion of the burner cap 6 that covers the distribution chamber 61. The burner body 5 is also provided with an engaged portion 54 with which the engaging piece 67 engages. The engaging piece 67 engages with the engaged portion 54, thereby preventing the burner cap 6 from rotating relative to the burner body 5.

[0020] More specifically, four engaging pieces 67, #1 to #4, are vertically attached at intervals in the circumferential direction to surround the upper gas inlet pipe 52b on the burner cap 6. Four protruding portions 55, #1 to #4, are provided at intervals in the circumferential direction on the burner body 5, protruding outward from the outer circumferential surface of the upper gas inlet pipe 52b, and the four engaging pieces 67 engage with the four engaged portions 54, #1 to #4, at the circumferential intervals between these protruding portions 55.

[0021] Here, the gas flow from the outlet 523 at the upper end of the gas inlet pipe upper portion 52b toward the flame hole 63 in the same direction as the engaging piece 67 interferes with the engaging piece 67, reducing the gas flow rate ejected from this flame hole 63. Therefore, the heating power is reduced at the circumferential location in the same direction as the engaging piece 67. If the burner cap 6 were provided with only one engaging piece 67, the heating power would be reduced only at the one circumferential location in the same direction as the engaging piece 67, and the uniformity of the heat distribution would be impaired. However, if multiple engaging pieces 67 are provided as in this embodiment, when the entire circumference of the burner A is divided into multiple circumferential ranges each including a portion in the same direction as each engaging piece 67, the heating power in these multiple circumferential ranges becomes uniform, ensuring uniformity of the heat distribution.

[0022] In this embodiment, the four engagement pieces 67, #1 to #4, are positioned in the same direction as the four trivet claws 32, i.e., the four trivet flame holes 63A. This causes the gas flow from the outlet 523 toward each trivet flame hole 63A to interfere with the engagement pieces 67, reducing the amount of gas ejected from each trivet flame hole 63A. This shortens the combustion flame of the gas ejected from each trivet flame hole 63A (trivet flame hole flame), preventing the trivet flame from coming into contact with the trivet claws 32 and generating CO.

[0023] However, when multiple engaging pieces 67 are provided as described above, even if the burner cap 6 is incorrectly set in a state where these engaging pieces 67 do not engage with the engaged portions 54 but instead ride up onto the convex portions 55, the burner cap 6 will not tilt, which may make it difficult for the user to recognize that the burner cap 6 has been incorrectly set.

[0024] Therefore, in this embodiment, two or more types of protrusions 55 with different upper surface heights are provided. Specifically, the #2 and #3 protrusions 55 located on the front depth side of the cooking appliance (left side in Figures 2, 4, and 5) have a higher upper surface height than the #1 and #4 protrusions 55 located on the rear depth side (right side in Figures 2, 4, and 5). As a result, when the engaging pieces 67 are not engaged with the corresponding engaged pieces 54, the engaging pieces 67 ride up onto the #2 and #3 protrusions 55, tilting the burner cap 6 so that the front depth side of the burner cap 6 is higher. This makes it easier for the user to recognize that the burner cap 6 has been set incorrectly.

[0025] Furthermore, in this embodiment, the circumferential spacing between the engaging pieces 67, 67 and the circumferential spacing between the engaged parts 54, 54 are not made uniform, but each engaging piece 67 can engage with a corresponding predetermined engaged part 54 only when the burner cap 6 is at a predetermined phase with respect to the burner body 5. More specifically, the circumferential width of the engaging piece 67 of #1 located at the rear in the same direction as the trivet flame hole 63A that also serves as an ignition flame hole is made wider than the circumferential widths of the other engaging pieces 67 of #2 to #4, and the circumferential width of the engaged part 54 of #1 located at the rear corresponding to the engaging piece 67 of #1 is also made wider than the circumferential widths of the other engaged parts 54 of #2 to #4. Therefore, the circumferential distance θ between the engaging piece 67 of #1 and the adjacent engaging pieces 67 of #2 and #4, and between the engaged part 54 of #1 and the adjacent engaged parts 54 of #2 and #4, is narrower than the circumferential distance θ' between the engaging piece 67 of #3 and the respective engaging pieces 67 of #2 and #4, and between the engaged part 54 of #3 and the respective engaged parts 54 of #2 and #4. Only when the burner cap 6 is in a predetermined phase with respect to the burner body 5, i.e., when the engaging piece 67 of #1 matches the engaged part 54 of #1, can each of the engaging pieces 67 of #1 to #4 be engaged with each of the engaged parts 54 of #1 to #4. Therefore, the mounting phase of the burner cap 6 with respect to the burner body 5 can be uniquely determined.

[0026] 6, it is also possible to make the circumferential widths of all the engaging pieces 67 and all the engaged parts 54 uniform, and to shift the positions of the engaging piece 67 of #2 and the engaged part 54 of #2 slightly backward (to the right in FIG. 6) so that the circumferential intervals θ between the engaging piece 67 of #1 and the engaging pieces 67 of #2 and #4 and between the engaged part 54 of #1 and the engaged parts 54 of #2 and #4 are narrower than the circumferential intervals θ' between the engaging piece 67 of #3 and the engaging pieces 67 of #2 and #4 and between the engaged part 54 of #3 and the engaged parts 54 of #2 and #4. In this case too, each engaging piece 67 can engage with the corresponding engaged part 54 only when the burner cap 6 is in a predetermined phase with respect to the burner body 5. In addition, the positions of the engaging piece 67 of #2 and the engaged portion 54 of #2 and the positions of the engaging piece 67 of #4 and the engaged portion 54 of #4 may be shifted rearward or forward, or at least one of the positions of the engaging piece 67 of #1 and the engaged portion 54 of #1 and the positions of the engaging piece 67 of #3 and the engaged portion 54 of #3 may be shifted laterally, so that the circumferential spacing between the engaging pieces 67, 67 and the circumferential spacing between the engaged portions 54, 54 are uneven.

[0027] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the height of the upper surfaces of the protrusions 55 of #2 and #3 on the front side in the depth direction is high, but the height of the protrusions 55 of #1 and #4 on the rear side in the depth direction may also be high. In this case, if the burner cap 6 is set incorrectly, the burner cap 6 tilts so that the rear side in the depth direction is higher. However, since it is easier for a user standing in front of the cooking appliance to recognize the tilt of the burner cap 6 if the front side in the depth direction is higher, it is desirable to raise the height of the upper surfaces of the protrusions 55 of #2 and #3 on the front side in the depth direction, as in the above embodiment. It is also possible to provide two or more types of engaging pieces 67 with different vertical lengths so that the burner cap 6 tilts when each engaging piece 67 is not engaged with each engaged piece 54.

[0028] In addition, while the above embodiment has four trivet claws 32 and four engaging pieces 67, the number of these may be other than four. Furthermore, the engaging pieces 67 may be positioned in a different direction from the trivet claws 32. While the cooker burner A of the above embodiment draws in primary air using the so-called radial venturi effect, it is also possible to provide a venturi section near the upstream end of the lower gas inlet pipe 52a and configure the burner to draw in primary air using the negative pressure generated in the venturi section. In this case, the lower gas inlet pipe 52a does not need to be formed straight in the vertical direction.

[0029] A...burner for cooking appliance, 2...top plate, 3...trivet, 32...trivet claws, 5...burner body, 51...bottom wall portion, 52...gas inlet pipe portion, 52a...lower part of gas inlet pipe, 52b...upper part of gas inlet pipe, 522...inlet, 523...outlet, 54...engaged portion, 55...convex portion, 6...burner cap, 61...distribution chamber, 62...outer peripheral wall portion of distribution chamber, 63...flame hole, 66...opposing plate portion, 67...engaging piece, 7...nozzle.

Claims

1. A burner for a cooking appliance that heats an object to be heated that is placed on a trivet on the top plate of the cooking appliance, comprising: a burner body having a bottom wall and a gas inlet pipe extending vertically through the bottom wall; a burner cap placed on the burner body so that a distribution chamber communicating with the gas inlet pipe is defined between the burner body and the burner cap; and a nozzle that injects fuel gas toward an inlet opening at the upstream end face of the gas inlet pipe, so that a mixture of primary air and fuel gas flowing in from the inlet opening is supplied to the distribution chamber from an outlet opening at the upper end face of the upper part of the gas inlet pipe, which is a part of the gas inlet pipe that extends above the bottom wall of the burner body; and a plurality of flame holes are provided at intervals in the circumferential direction on the outer peripheral wall of the distribution chamber that extends vertically so as to surround the outer periphery of the distribution chamber between the burner body and the burner cap. A burner for a heating cooker, characterized in that an engaging piece extending downward is attached to the part of the burner cap covering the distribution chamber, and an engaged part with which the engaging piece engages is provided on the burner body, and the engagement piece engages with the engaged part to prevent the burner cap from rotating relative to the burner body, and the burner body is provided with a plurality of convex parts protruding outward from the outer peripheral surface of the upper part of the gas inlet pipe at intervals in the circumferential direction, and the burner cap is provided with a plurality of engaging pieces that engage with a plurality of engaged parts formed by the plurality of circumferential intervals between these convex parts, and two or more types of convex parts with different upper surface heights are provided, or two or more types of engaging pieces with different vertical lengths are provided, so that the burner cap tilts when each engaging piece is not engaged with each engaged part.

2. A burner for a heating cooker as described in claim 1, characterized in that the circumferential spacing between the engaging pieces and the circumferential spacing between the engaged parts are not uniform, and each engaging piece can engage with a corresponding specified engaged part only when the burner cap is in a specified phase with respect to the burner body.

3. A burner for a cooking appliance as described in claim 1, characterized in that the lower part of the gas inlet pipe, which is the part of the gas inlet pipe extending downward from the bottom wall part of the burner body, is formed straight in the vertical direction, the inlet is opened at the lower end face of the lower gas inlet pipe, which is the upstream end face of the gas inlet pipe, and an opposing plate part is provided above the outlet opening with a gap between them, which diffuses the gas flow flowing out from the outlet opening in the radial direction and has the effect of drawing in primary air from the inlet opening.

4. A burner for a heating cooker according to any one of claims 1 to 3, characterized in that each of the engagement pieces is arranged in the same direction as each of the trivet claws provided on the trivet.

5. A cooking device comprising the burner for cooking devices according to claim 1 or 2.

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