Gas burner and heating cooker

Abstract

This gas burner comprises: a burner body 5 which has a gas inflow pipe portion 52 extending vertically through a bottom wall portion 51; and a burner cap 6 which defines a distribution chamber 61 together with the burner body 5, wherein: an engagement piece 67 extends down from the burner cap 6; an engaged portion 54 with which the engagement piece 67 engages is provided on the burner body 5; and by the engagement piece 67 engaging with the engaged portion 54, the burner cap 6 is rotationally secured with respect to the burner body 5. Said gas burner makes it possible to suppress a difficulty in detaching the burner cap 6 as a result of adhesion of the engagement piece 67 to the bottom wall portion 51 of the burner body 5 due to boiling over.　An upper surface of the bottom wall portion 51 of the burner body 5 is provided with: an engaged-portion bottom surface portion 51a facing the lower end of the engagement piece 67 with a vertical gap therebetween; a lowermost portion 51b which is the lowest portion of the upper surface of the bottom wall portion; and an inclined portion 51c which is inclined downwards from the engaged-portion bottom surface portion 51a towards the lowermost portion 51b.

Description

Gas burners and cooking appliances

[0001] The present invention relates to a gas 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 for injecting fuel gas toward an inlet opening at the upstream end face of the gas inlet pipe portion, and a cooking appliance equipped with this gas burner.

[0002] A conventional gas burner of this type is disclosed in, for example, Patent Document 1, in which a mixed gas of primary air and fuel gas flowing in from an inlet is supplied to a 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 extending 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 extending in the vertical direction between the burner body and the burner cap. Also, in this gas burner, an engaging piece extending downward is suspended from 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 of the engaging piece with the engaged part prevents the burner cap from rotating relative to the burner body.

[0003] In the conventional gas burner, boil-over that seeps into the distribution chamber from the flame holes accumulates on the bottom wall of the burner body, and this boil-over can reach the bottom end of the engagement piece, causing the engagement piece to adhere to the bottom wall of the burner body through the boil-over, making it difficult to remove the burner cap.

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

[0005] In view of the above, the present invention aims to provide a gas burner and a cooking appliance equipped with this gas burner that can prevent the burner cap from becoming difficult to remove due to the engagement piece becoming stuck to the bottom wall portion of the burner body due to boiling over.

[0006] In order to solve the above problems, the first invention of the present application is a gas 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 that a distribution chamber communicating with the gas inlet pipe portion is defined between the burner body and the burner cap; and a nozzle for injecting fuel gas toward an inlet opening at an upstream end face of the gas inlet pipe portion, wherein a mixed gas 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 gas inlet pipe upper portion, which is a part of the gas inlet pipe portion extending above the bottom wall portion of the burner body, and a gas outlet opening at an upper end face 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, outside the distribution chamber, The invention is characterized in that the outer peripheral wall of the distribution chamber extending vertically so as to surround the periphery is provided with a plurality of flame holes spaced apart in the circumferential direction, the portion of the burner cap covering the distribution chamber is provided with an engaging piece extending downward, the burner body is provided with an engaged part with which the engaging piece engages, and the engagement piece engages with the engaged part to prevent the burner cap from rotating relative to the burner body, and the upper surface of the bottom wall of the burner body is provided with a bottom surface part of the engaged part that faces the lower end of the engaging piece with a vertical gap when the engaging piece is engaged with the engaged part, a lowermost part that is the lowest part of the upper surface of the bottom wall, and an inclined part that slopes downward from the bottom surface part of the engaged part to the lowermost part.

[0007] According to this invention (first invention), even if boil-over seeps into the distribution chamber from the flame holes, the boil-over will preferentially collect at the lowest part of the upper surface of the bottom wall of the burner body. The boil-over is less likely to reach the bottom surface of the engaged part, which is located above the lowest part via the inclined part. Therefore, it is possible to prevent the engagement piece from becoming stuck to the bottom wall of the burner body due to boil-over, making it difficult to remove the burner cap.

[0008] In the present invention, the engaging piece is preferably provided so as to contact or closely face the outer peripheral surface of the upper part of the gas inlet pipe. This positioning of the engaging piece radially inward prevents boil-over from adhering to the engaging piece through the flame hole. This also prevents the engaging piece from adhering to the engaging piece and getting stuck between the lower end of the engaging piece and the bottom surface of the engaged part.

[0009] Furthermore, in the present invention, it is desirable that the height of the portion of the underside of the burner cap where the engaging piece is hung is higher than the height of the upper edge of the flame hole on the inner peripheral surface of the outer wall of the distribution chamber, which prevents boil-over that seeps in from the flame hole from running down the underside of the burner cap and adhering to the engaging piece.

[0010] In the present invention, the lowermost portion of the upper surface of the bottom wall of the burner body is preferably annularly arranged so as to surround the upper portion of the gas inlet pipe. This allows boil-over to accumulate almost uniformly in the circumferential direction at the lowermost portion of the annular shape. Therefore, uneven accumulation of the boil-over amount can be prevented, which causes unevenness in the amount of ejected gas in the circumferential direction and disrupts the heat distribution.

[0011] Furthermore, the gas burner 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 gas inlet pipe lower part, 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, an inlet is opened in the lower end face of the gas inlet pipe lower part, which is the upstream end face of the gas inlet pipe part, and an opposing plate part is provided above and opposite to the outlet opening at the upper end face of the gas inlet pipe upper part with a gap therebetween, and that 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).

[0012] 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) is a perspective view of a burner cap of the burner for a cooking device according to an embodiment, as seen obliquely from below, and (b) is a perspective view of a burner body of the burner for a cooking device according to an embodiment, as seen obliquely from above.

[0013] 1 to 3 show a cooking appliance equipped with a gas 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 formed in the top plate main body 21 from above. A trivet 3 is disposed on the cover plate 22. A gas burner A that 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.

[0014] 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.

[0015] The gas burner A 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.

[0016] 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 as an ignition means and a thermocouple 9 for flame detection.

[0017] 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.

[0018] 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.

[0019] 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).

[0020] 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.

[0021] More specifically, the burner cap 6 is provided with four engaging pieces 67, located radially outward from the outlet 523 and radially inward from the trivet inner peripheral surface 62a, which is the inner peripheral surface of the portion of the distribution chamber outer peripheral wall 62 where the trivet holes 63A are provided. The engaging pieces 67 correspond to the four trivet holes 63A. The burner body 5 also has four convex portions 55, spaced circumferentially, protruding outward from the outer peripheral surface of the gas inlet pipe upper portion 52b. The engaging pieces 67 engage with four engaged portions 54 at four circumferential intervals between the convex portions 55. This configuration allows the engaging pieces 67 to interfere with the gas flow from the outlet 523 toward the trivet holes 63A, reducing the gas flow rate emitted from each trivet hole 63A. This shortens the combustion flame of the gas emitted from each trivet hole 63A, thereby reducing CO2 emissions caused by the combustion flame coming into contact with the trivet claws 32.

[0022] Furthermore, the #1 engaging piece 67 located radially inward of the trivet flame hole 63A that also serves as an ignition flame hole has a wider circumferential width than the other engaging pieces 67, and the #1 engaged part 54 with which the #1 engaging piece 67 engages also has a wider circumferential width than the other engaged parts 54. Therefore, each engaging piece 67 can engage with the corresponding predetermined engaged part 54 only when the burner cap 6 is in a predetermined phase with respect to the burner body 5 where the #1 engaging piece 67 matches the #1 engaged part 54.

[0023] However, if the boil-over that has entered the distribution chamber 61 from the flame hole 63 reaches the lower end of the engaging piece 67, the engaging piece 67 may become stuck to the bottom wall portion 51 of the burner body 5 through the boil-over, making it difficult to remove the burner cap 6.

[0024] 3, the upper surface of the bottom wall 51 of the burner body 5 is provided with an engaged portion bottom surface portion 51a that faces the lower end of the engaging piece 67 with a vertical gap when the engaging piece 67 is engaged with the engaged portion 54, a lowest portion 51b that is the lowest part of the upper surface of the bottom wall 51, and an inclined portion 51c that slopes downward from the engaged portion bottom surface portion 51a to the lowest portion 51b. The lowest portion 51b is provided in an annular shape so as to surround the periphery of the gas inlet pipe upper portion 52b at a position radially outward from the protrusion 55.

[0025] With this, even if boil-over seeps into the distribution chamber 61 from the flame holes 63, the boil-over will preferentially accumulate at the lowest part 51b on the upper surface of the bottom wall part 51 of the burner body 5. The boil-over is less likely to reach the bottom surface part 51a of the engaged part, which is located above the lowest part 51b via the inclined part 51c. This prevents the burner cap 6 from becoming difficult to remove due to the engagement piece 67 sticking to the bottom wall part 51 of the burner body 5 due to boil-over. Furthermore, because the lowest part 51b is annular, boil-over accumulates at the lowest part 51b almost uniformly in the circumferential direction. This prevents uneven accumulation of the amount of gas ejected from the burner body 51, resulting in uneven heat distribution.

[0026] In this embodiment, the engaging piece 67 is provided radially inward so as to closely face the outer circumferential surface of the gas inlet pipe upper portion 52b. This separates the engaging piece 67 from the flame hole 63, preventing boil-over from adhering to the engaging piece 67 through the flame hole 63. This also prevents the engaging piece 67 from adhering to the engaging piece 67 from getting between the lower end of the engaging piece 67 and the engaged portion bottom surface portion 51a, thereby preventing the engaging piece 67 from sticking.

[0027] Furthermore, in this embodiment, the height of the portion of the underside of the burner cap 6 where the engaging piece 67 is suspended is set higher than the height of the upper edge of the flame holes 63 on the inner peripheral surface of the distribution chamber outer peripheral wall portion 62. Therefore, it is possible to prevent boil-over that seeps in from the flame holes 63 from running down the underside of the burner cap 6 and adhering to the engaging piece 67.

[0028] 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 engaging piece 67 is closely opposed to the outer circumferential surface of the gas inlet pipe upper portion 52b. However, the engaging piece 67 may abut against the outer circumferential surface. Furthermore, in the above embodiment, the engaged portions 54 are defined by the spacing between the protrusions 55 protruding from the outer circumferential surface of the gas inlet pipe upper portion 52b. However, it is also possible to form grooves in the outer circumferential surface of the gas inlet pipe upper portion 52b and define the engaged portions 54 using these grooves. In this case, the grooves also become part of the outer circumferential surface of the gas inlet pipe upper portion 52b, and therefore, engaging the engaging piece 67 with the groove is included in abutting the outer circumferential surface of the gas inlet pipe upper portion 52b.

[0029] Furthermore, in the above embodiment, the lowermost portion 51b of the upper surface of the bottom wall portion 51 of the burner body 5 is annularly disposed radially outward from the engaging portion 54, but it is also possible to provide the lowermost portion 51b so that it extends radially between the multiple engaging portions 54. Also, in the above embodiment, four engaging pieces 67 are provided corresponding to the four trivet flame holes 63A so that the flow rate of gas ejected from the trivet flame holes 63A can be limited by the engaging pieces 67. However, if the engaging piece 67 does not have this function, only one engaging piece 67 may be provided. Furthermore, while the gas burner A in the above embodiment draws in primary air using the radial Venturi effect, it is also possible to provide a venturi portion near the upstream end of the lower gas inlet pipe 52a and configure it to draw in primary air using negative pressure generated in the venturi portion. In this case, the lower gas inlet pipe 52a does not have to be formed straight in the vertical direction.

[0030] A...gas burner, 5...burner body, 51...bottom wall portion, 51a...bottom surface portion of engaged portion, 51b...lower portion, 51c...inclined portion, 52...gas inlet pipe portion, 52a...lower portion of gas inlet pipe, 52b...upper portion of gas inlet pipe, 522...inlet, 523...outlet, 54...engaged 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 gas burner 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 for injecting fuel gas toward an inlet opening at the upstream end face of the gas inlet pipe, wherein 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 upper part of the gas inlet pipe, which is a part of the gas inlet pipe extending above the bottom wall of the burner body; a plurality of flame holes are provided at intervals in the circumferential direction on the outer peripheral wall of the distribution chamber extending vertically to surround the outer periphery of the distribution chamber between the burner body and the burner cap; an engaging piece extending downward is suspended from the part of the burner cap covering the distribution chamber; an engaged part with which the engaging piece engages is provided on the burner body; and the burner cap is prevented from rotating relative to the burner body by the engaging piece engaging with the engaged part. A gas burner characterized in that the upper surface of the bottom wall portion of the burner body is provided with a bottom surface portion of the engaged portion that faces the lower end of the engaging piece with a vertical gap when the engaging piece is engaged with the engaged portion, a lowest part that is the lowest part of the upper surface of the bottom wall portion, and an inclined part that slopes downward from the bottom surface portion of the engaged portion to the lowest part.

2. A gas burner according to claim 1, wherein said engaging piece is provided so as to contact or to face closely to the outer circumferential surface of the upper part of said gas inlet pipe portion.

3. A gas burner as described in claim 1 or 2, characterized in that the height of the portion of the underside of the burner cap where the engaging piece is suspended is higher than the height of the upper edge of the flame hole on the inner surface of the outer wall portion of the distribution chamber.

4. A gas burner according to claim 1 or 2, characterized in that the lowest part is provided in an annular shape so as to surround the upper part of the gas inlet pipe.

5. A gas burner 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 and opposite the outlet with a gap, which diffuses the gas flow flowing out from the outlet in the radial direction and has the effect of drawing in primary air from the inlet.

6. A cooking device comprising the gas burner according to any one of claims 1, 2 and 5.

Images