Gas stove

Abstract

To suppress the generation of an unexpected large space near a dent part in a gas cooking stove having a configuration in which a protrusion part of a burner cap enters into the dent part of a burner body.SOLUTION: A gas cooking stove 1 includes a burner body 6A, and a burner cap 20 mounted on the burner body 6A. In the burner cap 20, a lower surface part 35 of a flange part 32 is provided with: a first protrusion 181 arranged at one side of a protrusion part in the circumferential direction and protruding to a lower side; a second protrusion 182 arranged at the other side of the protrusion part in the circumferential direction and protruding to a lower side; and a plurality of partition walls 144 arranged between the first protrusion 181 and the second protrusion 182 in the circumferential direction. A part of each of the first protrusion 181 and the second protrusion 182 is arranged closer to a center of the flange part 32 than an end part in a radial outside of the flange part 32 in a dent part 66Z.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a gas stove.

Background Art

[0002] In the gas burner disclosed in Patent Document 1, six flame transfer portions 71 to 76 are provided at 60° pitch intervals in the circumferential direction with respect to the center of the cylindrical wall 15. The flame transfer portions 71 to 76 are predetermined portions respectively corresponding to six hotplate claws provided on the hotplate when the gas burner 1 is installed on the stove. Further, in the gas burner of Patent Document 1, a positioning projection 16 is provided vertically at the flame transfer portion 74. The projection 16 is fitted into a positioning hole provided in the seating surface 2A of the burner body 2 from above.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the gas burner of Patent Document 1, in the burner body that supports the burner cap, a hole (positioning hole) into which a positioning projection is inserted is provided. However, there is a concern that the gas flow becomes unstable near this positioning hole. For example, if the positioning hole cannot be formed with high precision, an unexpected large gap is likely to occur between this hole and the lower surface of the burner cap or in its vicinity. In particular, when the burner body is formed by press working of a metal material (so-called press molding), it is difficult to form details with high precision, so there is a concern that the position and shape of the positioning hole deviate from the designed shape. Also, such problems may occur even other than press working. If such a large gap occurs, there is a concern that a larger amount of gas than expected from the design is supplied from the flame holes provided outside the projection and the hole (positioning hole).

[0005] One of the objectives of this disclosure is to prevent the creation of an unexpectedly large space near a recess in a gas stove in which a protruding part of the burner cap fits into a recess in the burner body. [Means for solving the problem]

[0006] One of the disclosures is a gas stove, The burner body that supplies gas, A burner cap comprising a cylindrical portion and a flange portion protruding from the cylindrical portion, which is attached to the burner body, A gas stove having, The burner body comprises an upper surface having an annular opposing surface facing the flange portion, and a recessed portion having a structure recessed relative to the upper surface. The burner cap comprises a plurality of flame hole grooves provided on the lower surface of the flange portion, and a projection provided on the lower surface that fits into the recessed portion, The plurality of flame hole grooves include a plurality of main flame hole grooves that together with the opposing surface constitute a main flame hole, and a plurality of flame transfer flame hole grooves that together with the opposing surface constitute a flame transfer flame hole, The lower surface portion is provided with a first protrusion located on one side of the protrusion in the circumferential direction of the flange portion and projecting downward, a second protrusion located on the other side of the protrusion in the circumferential direction and projecting downward, and a plurality of partition walls located between the first protrusion and the second protrusion in the circumferential direction. The first gas flow path is formed by comprising the first convex portion and the protruding portion, The second gas flow path is formed by comprising the second convex portion and the protruding portion, Of the plurality of flame transfer grooves, the first flame transfer groove comprises a first wall that forms part of the first protrusion and one of the plurality of partition walls, Of the plurality of flame transfer grooves, the second flame transfer groove comprises a second wall that forms part of the second protrusion and another partition wall among the plurality of partition walls. The outer circumference of the flange portion is provided with the outlets for the first flame transfer groove and the second flame transfer groove. A portion of each of the first and second protrusions is positioned closer to the center of the flange portion than the radially outer end of the flange portion in the recess. [Effects of the Invention]

[0007] According to the technology disclosed herein, in a gas stove in which the protruding part of the burner cap fits into the recessed part of the burner body, it is possible to suppress the creation of an unexpectedly large space near the recessed part. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic perspective view illustrating a gas stove according to the first embodiment. [Figure 2] Figure 2 is a perspective view illustrating a gas burner used in the gas stove of the first embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view illustrating a cross-section of the gas burner shown in Figure 2, obtained by cutting through the main flame hole and along the central axis. [Figure 4] Figure 4 is a schematic cross-sectional view illustrating a configuration of the gas burner shown in Figure 2 with the cover omitted, showing a cross-section taken at a point passing through the flame-holding hole and the central axis. [Figure 5] Figure 5 is an exploded perspective view showing a portion of the gas burner shown in Figure 2. [Figure 6] Figure 6 is a perspective view of the burner cap body of the gas burner shown in Figure 2, viewed from below. [Figure 7] Figure 7 is a bottom view of the burner cap body shown in Figure 6. [Figure 8] Figure 8 is a schematic cross-sectional view of the gas burner in Figure 2 with the cover omitted. [Figure 9] Figure 9 is an enlarged view showing a portion of Figure 8. [Figure 10]FIG. 10 is an enlarged view showing the vicinity of the protruding portion of a perspective view of the burner cap body as viewed from below. [Figure 11] FIG. 11 is an enlarged view showing the vicinity of the protruding portion in the bottom view of FIG. 7. [Figure 12] FIG. 12 is a view in which the lower surface portion of the burner cap body and the outer edge of the recessed portion are projected onto a virtual plane orthogonal to the axis.

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be listed and exemplified. Note that the features [1] to [6] exemplified below may be combined in any non - conflicting combination.

[0010] 〔1〕 A burner body for supplying gas, [[ID=2‎0]] A burner cap including a cylindrical portion and a flange portion protruding from the cylindrical portion, and being attached to the burner body, A gas stove having the above, The burner body includes an upper surface portion having an annular opposing surface facing the flange portion, and a recessed portion having a configuration recessed with respect to the upper surface portion. The burner cap includes a plurality of flame hole grooves provided on the lower surface portion of the flange portion, and a protruding portion provided on the lower surface portion and entering the recessed portion. The plurality of flame hole grooves include a plurality of main flame hole grooves that form a main flame hole together with the opposing surface, and a plurality of flame transfer hole grooves that form a flame transfer hole together with the opposing surface. On the lower surface portion, a first convex portion disposed on one side of the protruding portion in the circumferential direction of the flange portion and protruding downward, a second convex portion disposed on the other side of the protruding portion in the circumferential direction and protruding downward, and a plurality of partition walls disposed between the first convex portion and the second convex portion in the circumferential direction are provided. The first convex portion and the protruding portion constitute a first gas flow path. The second convex portion and the protruding portion constitute a second gas flow path. Of the plurality of flame transfer grooves, the first flame transfer groove comprises a first wall that forms part of the first protrusion and one of the plurality of partition walls, Of the plurality of flame transfer grooves, the second flame transfer groove comprises a second wall that forms part of the second protrusion and another partition wall among the plurality of partition walls. The outer circumference of the flange portion is provided with the outlets for the first flame transfer groove and the second flame transfer groove. A portion of each of the first and second protrusions is positioned closer to the center of the flange portion than the radially outer end of the flange portion in the recess. Gas stove.

[0011] The gas stove described in [1] can prevent the space near the recess (especially the space on both sides of the circumferential direction of the recess) from becoming too large due to the positional relationship between the first and second protrusions. Therefore, this gas stove is less likely to cause problems (such as excessive gas supply beyond the design assumption) resulting from the creation of an unexpectedly large space near the recess.

[0012] [2] A portion of the first protrusion and the second protrusion covers the internal space formed between the inner wall of the recess and the protrusion from above. The gas stove described in [1].

[0013] The gas stove described in [2] can suppress the large amount of gas flowing from the vicinity of the protruding part into the vicinity of the recessed part, or the large amount of gas flowing out from within the recessed part. Therefore, this gas stove can easily suppress the excessive flow of gas from the vicinity of the recessed part to the first flame transfer hole groove and the second flame transfer hole groove.

[0014] [3] In the circumferential direction, a third protrusion is provided on the side opposite to the first protrusion from the projection, In the circumferential direction, a fourth protrusion is provided on the side opposite to the second protrusion from the protruding portion. The first main flame hole groove is formed by comprising the first protrusion and the third protrusion, The second main flame hole groove is formed by comprising the second protrusion and the fourth protrusion, The first protrusion protrudes downward from the third protrusion, The second protrusion protrudes downward from the fourth protrusion, The radially inner end of the first protrusion is positioned closer to the center of the flange than the radially inner end of the third protrusion. The radially inner end of the second protrusion is positioned closer to the center of the flange than the radially inner end of the fourth protrusion. A gas stove as described in [1] or [2].

[0015] The gas stove described in [3] can have the first protrusion positioned lower and more radially inward, and the second protrusion positioned lower and more radially inward. Therefore, this gas stove can ensure gas flow through the first and second gas flow paths while more reliably preventing excessive gas flow into the first and second flame transfer grooves.

[0016] [4] A portion of each of the first and second protrusions is positioned closer to the center of the flange portion than the radially outer end of the flange portion on the protrusion. A gas stove that has one of the following descriptions: [1] through [3].

[0017] The gas stove described in [4] can prevent the space between the protruding part and each convex part from becoming too large near the recessed part, even if manufacturing errors occur, and thus can suppress "excessive gas flow caused by this space becoming too large."

[0018] [5] The inner flame transfer groove of the plurality of flame transfer grooves is provided with the plurality of partition walls, The outer circumference of the flange portion is provided with an outlet for the inner flame transfer hole groove. The third gas flow path is configured with the aforementioned protrusion and the plurality of partition walls, The first gas passage allows at least a portion of the gas flowing through the first gas passage to flow into the third gas passage. The second gas passage allows at least a portion of the gas flowing through the second gas passage to flow into the third gas passage. The third gas passage directs at least a portion of the gas flowing through the third gas passage into the inner flame transfer hole groove. A gas stove that lists one of the following: [1] through [4].

[0019] The gas stove described in [5] allows the gas flowing through the first and second gas channels to flow not only through the first and second flame transfer grooves, but also through the inner flame transfer groove due to the presence of a third gas channel. Therefore, this gas stove improves the dispersion of gas and further suppresses localized gas concentration.

[0020] [6] A stepped portion is provided between the protruding portion and the plurality of partition walls, The stepped portion covers the internal space formed between the inner wall portion of the recessed portion and the protruding portion from above. A gas stove that lists one of the following: [1] through [5].

[0021] The gas stove described in [6] can prevent gas flowing near the protruding portion from flowing into the recessed portion due to the presence of the stepped portion. In this gas stove, the first protrusion, the second protrusion, and the stepped portion work synergistically near the recessed portion, making it even easier to suppress excessive gas flow from the vicinity of the recessed portion to the vicinity of the flame transfer hole groove on the outside.

[0022] <First Embodiment> The following describes a gas stove 1, etc., equipped with gas burners 4, 5, and 6 for a gas stove according to the first embodiment.

[0023] 1. Overview of gas stoves The gas stove 1 shown in Figure 1 is a built-in stove that is incorporated into, for example, a cabinet (not shown in Figure 1). The gas stove 1 includes gas burners (cooktop burners) 4, 5, 6, a housing 2, a top plate 3, a grill section 8, and the like.

[0024] In the following description, in the gas stove 1 shown in Figure 1, the first direction of the plate surface direction of the plate-shaped top plate 3 is the front-to-back direction. The above plate surface direction is a planar direction parallel to a predetermined flat surface that forms the upper surface of the top plate 3. In the representative example described below (Figure 1, etc.), the first direction is the short side direction when the top plate 3 is viewed from above, and is the front-to-back direction. In the above representative example (Figure 1, etc.), the second direction of the plate surface direction of the top plate 3 that is perpendicular to the above first direction is the left-to-right direction. In the above representative example (Figure 1, etc.), the second direction is the long side direction when the top plate 3 is viewed from above, and is the left-to-right direction. The direction perpendicular to the above front-to-back direction and perpendicular to the above left-to-right direction is the up-to-down direction. In the above representative example (Figure 1, etc.), the plate thickness direction of the top plate 3 is the third direction, and is the up-to-down direction.

[0025] The housing 2 shown in Figure 1 is mainly made of, for example, a known metal material. The housing 2 constitutes the outer casing of the gas stove 1. The housing 2 houses some or all of the gas burners 4, 5, 6 and other components. The housing 2 has a pair of side walls on both the left and right sides, and a rear wall (not shown in Figure 1) is provided connected to the rear ends of these side walls. The front part of the housing 2 (not shown in Figure 1) is constructed in a frame-like or wall-like manner, and includes, for example, a frame that is arranged to span across the aforementioned pair of side walls. Furthermore, a bottom wall (not shown in Figure 1) is connected to the lower part of this front part, the pair of side walls, and the rear wall. The housing 2 has a box-like shape with its upper end open, and its internal space is enclosed by this front part, the pair of side walls, the rear wall, and the bottom wall.

[0026] The top plate 3 shown in Figure 1 is fixed to the upper end of the housing 2. The top plate 3 is positioned on the housing 2 in such a way that it partially or completely closes the opening at the upper end of the housing 2. The top plate 3 has a rectangular plate shape in plan view. The top plate 3 is provided with multiple openings (through holes) 3A, 3B, and 3C for exposing the gas burners 4, 5, and 6.

[0027] The gas burners 4, 5, and 6 shown in Figure 1 are provided to correspond to the respective openings 3A, 3B, and 3C formed in the top plate 3. Gas burner 4 is positioned to be inserted into opening 3A, which is located near the right and front ends of the top plate 3. Gas burner 5 is positioned to be inserted into opening 3B, which is located near the left and front ends of the top plate 3. Gas burner 6 is positioned to be inserted into opening 3C, which is located in the center of the top plate 3 in the left-right direction and near the rear end. A grill section 8 is provided near the left-right center of the housing 2. The grill section 8 includes a box-shaped grill compartment (detailed illustration omitted in Figure 1), a grill door 8A for opening and closing the grill compartment, and a grill burner (detailed illustration omitted in Figure 1) which is configured as a gas burner and is located inside the grill compartment.

[0028] As shown in Figure 1, two ignition buttons 11 and 14 are provided on the front of the gas stove 1, near the right end. Two ignition buttons 12 and 13 are provided on the front of the gas stove 1, near the left end. Ignition button 11 is an operation button for igniting and extinguishing the gas burner 4. Ignition button 12 is an operation button for igniting and extinguishing the gas burner 5. Ignition button 13 is an operation button for igniting and extinguishing the gas burner 6. Ignition button 14 is an operation button for igniting and extinguishing the gas burner of the grill section 8. Each of the ignition buttons 11, 12, 13, and 14 is positioned so that it can be seen and operated from the front. Each of the ignition buttons 11, 12, 13, and 14 is configured to be displaceable between a protruding position that extends forward and a retracted position that is moved backward from the protruding position. Each of the ignition buttons 11, 12, 13, and 14 is configured to be rotatable, and the flame of the gas burner corresponding to each button is adjusted by the rotational position of each ignition button 11, 12, 13, and 14.

[0029] Multiple openings 3A, 3B, and 3C provided in the top plate 3 are through holes. A burner cap 21, which forms the head of the gas burner 4, is placed inside opening 3A. A burner cap 22, which forms the head of the gas burner 5, is placed inside opening 3B. A burner cap 20, which forms the head of the gas burner 6, is placed inside opening 3C. The two burner caps 21 and 22 have the same configuration as each other. Burner caps 21, 22 and burner cap 20 have the same configuration except for their different sizes. Metal trivets 7 are provided on the top plate 3 so as to surround each of the burner caps 20, 21, and 22.

[0030] 2. Overview of Gas Burners The following section will primarily detail the configuration and operation of the gas burner 6. As shown in Figures 2 to 5, the gas burner 6 comprises a burner body 6A and a burner cap 20 attached to the burner body 6A. As shown in Figure 1, the gas burner 6 is supported within the housing 2 and fixed to the housing 2 directly or indirectly via other components. The gas burner 6 straddles the upper and lower sides of the top plate 3 through the opening 3C.

[0031] The burner body 6A shown in Figures 2 to 5 is a component for supplying combustion gas, and also a component that supports and holds the burner cap 20 from below. The burner body 6A is also a component that constitutes a path (flow path) for supplying combustion gas from a combustion gas flow path provided outside itself to the burner cap 20. The burner body 6A is a metal part formed by, for example, press working (so-called press molding) of a metal material, for example, by sandwiching the metal material (raw material) to be processed between molds and forming (plastic deformation). As shown in Figure 3, the burner body 6A mainly comprises a cylindrical lower section 6B and a throat section 6C connected to the lower section 6B. The lower section 6B is the part that faces the burner cap 20 from below. The lower section 6B is the part that forms a mixed gas chamber 6Z inside itself, and has a structure that surrounds the outside of the space inside the mixed gas chamber 6Z. The lower mounting section 6B, for example, receives and supports the flange section 32 of the burner cap body 30. The throat section 6C is a cylindrical portion extending from the lower mounting section 6B and constitutes a pipeline for gas flow. The throat section 6C functions as a mixing tube for mixing fuel gas and combustion air. The mixed gas chamber 6Z shown in Figure 3 communicates with the inside of the throat section 6C (Figure 2). The mixed gas chamber 6Z constitutes a space for mixing fuel gas supplied via the throat section 6C with combustion air. The combustion gas in the mixed gas chamber 6Z spreads radially outward from the burner cap 20 and is released from the outer circumference of the flange section 32 through each flame hole 70. Specifically, the flame holes 70 are one of the main flame hole 71, the flame transfer flame hole 72, or the flame retaining hole 73.

[0032] The burner cap 20 shown in Figures 2 to 5 functions as a burner head. As shown in Figure 3, the burner cap 20 is a component attached to the burner body 6A and is positioned above the lower mounting section 6B. The burner cap 20 is configured in an annular shape as a whole. The burner cap 20 comprises an annular burner cap body 30 and a cover body 40 fixed to the burner cap body 30. The burner cap 20 is assembled by the burner cap body 30 and the cover body 40 being assembled together. The burner cap body 30 is a component with flame hole grooves 110 formed on its outer circumference. The cover body 40 is a component that covers the burner cap body 30. As shown in Figure 1, near any of the flame hole grooves 110, an ignition electrode 10 and a thermocouple (not shown) for flame detection are provided. In Figures 2 to 5, only the reference numerals of some of the flame hole grooves 110 are shown, but numerous flame hole grooves 110 are formed around the entire circumference of the burner cap body 30.

[0033] As shown in Figures 2 to 4, the temperature sensor 9 is positioned to penetrate the lower mounting section 6B and the center of the burner cap 20. The temperature sensor 9 functions to detect the temperature of the bottom of a cooking utensil (such as a cooking pot) placed on the trivet 7 by contacting the bottom of the utensil. In Figures 3 and 4, components other than the temperature sensor 9 are shown in cross-section, and the configuration of the temperature sensor 9 is schematically shown in a side view.

[0034] In the gas stove 1 shown in Figure 1, for example, when the ignition button 13 is pressed, fuel gas is supplied to the burner body 6A shown in Figures 2 to 4 along with primary air, and the mixture flows out from the numerous flame holes 110 of the burner cap 20 attached to the burner body 6A. When the ignition button 13 is pressed, a controller (not shown) located inside the gas stove 1 sparks an electrode 10 close to the burner cap 20 shown in Figures 2 to 4, igniting the mixture and generating a flame around the burner cap 20. This allows the bottom of the cooking utensil placed on the trivet 7 around the burner cap 20 to be heated, enabling cooking.

[0035] 3. Details of the burner body As shown in Figures 2 and 5, the burner body 6A has a configuration in which the lower mounting section 6B and the throat section 6C are integrally connected. The lower mounting section 6B is a cylindrical base on which the burner cap 20 is mounted. The lower mounting section 6B comprises a cylindrical section 60 and a lower connecting section 74.

[0036] As shown in Figure 5, the cylindrical portion 60 is cylindrical and constitutes the upper end of the burner body 6A. The cylindrical portion 60 is the outer inner wall portion of the mixed gas chamber 6Z. The cylindrical portion 60 comprises an inner circumferential wall portion 62, an outer circumferential wall portion 64, and an upper surface portion 66. The inner circumferential wall portion 62 is cylindrical and constitutes the outer inner wall portion of the mixed gas chamber 6Z. The inner circumferential surface of the inner circumferential wall portion 62 is a cylindrical surface centered on a predetermined central axis G shown in Figure 3. The outer circumferential wall portion 64 is cylindrical and surrounds the inner circumferential wall portion 62. The upper surface portion 66 connects the upper end of the inner circumferential wall portion 62 and the upper end of the outer circumferential wall portion 64. The upper surface portion 66 constitutes the upper end of the burner body 6A. The upper surface portion 66 is arranged in an annular shape. The upper surface portion 66 is provided with an opposing surface 66A. The upper surface portion 66 is a part that constitutes a portion of each flame hole 70. The opposing surface 66A is an annular surface that faces the flange portion 32 (annular portion) of the burner cap 20. The opposing surface 66A is a surface that is positioned opposite the lower surface portion 35 of the flange portion 32, and more specifically, it is a surface that is positioned opposite at least the groove portion 35B. Furthermore, the opposing surface 66A is positioned opposite each flame hole groove 110. The opposing surface 66A constitutes a part of the inner surface of each flame hole 70 (main flame hole 71, flame transfer flame hole 72, flame retention hole 73). The opposing surface 66A is arranged in an annular shape with the central axis G as the center. The opposing surface 66A is an inclined surface that is lower as it moves inward (towards the inner peripheral wall portion 62), and is configured as a mortar shape overall. The diameter of the opposing surface 66A with respect to the central axis G is smaller as it moves downward. The opposing surface 66A preferably functions as a support surface that supports the flange portion 32 of the burner cap body 30 from below.

[0037] Below the cylindrical portion 60, a lower connecting portion 74 is provided, which is connected to the cylindrical portion 60. The lower connecting portion 74 comprises an annular outer wall portion 75 connected to the inner circumferential wall portion 62, a bottom wall portion 78 connected to the lower end of the outer wall portion 75, and a cylindrical support cylinder 76 rising upward from the bottom wall portion 78. The upper end of the outer wall portion 75 is connected to the lower end of the inner circumferential wall portion 62, and the outer wall portion 75 and the inner circumferential wall portion 62 constitute the outer inner wall portion (annular wall portion) of the mixed air chamber 6Z. The bottom wall portion 78 functions as the bottom wall of the mixed air chamber 6Z. The support cylinder 76 is positioned to straddle the area inside the inner circumferential wall portion 62 and the area inside the outer wall portion 75 in the vertical direction. The support cylinder 76 has a cylindrical shape centered on the central axis G, with an open upper end. The burner cap body 30 has a configuration in which the cylindrical portion 31 of the burner cap body 30 is inserted into the support cylinder 76 from above. The cylindrical portion 31 and the support cylinder 76 form the inner wall portion (annular wall portion) of the mixed gas chamber 6Z. The outer wall portion 75 is integrally formed with the throat portion 6C. The internal space of the outer wall portion 75 (the space within the mixed gas chamber 6Z) is designed to allow gas to flow in from the internal space of the throat portion 6C.

[0038] 4. Details of the burner cap The following description concerns the detailed configuration of the burner cap 20. As shown in Figures 2 to 5, the burner cap body 30 is attached to the burner body 6A from above. The burner cap body 30 is attached to the burner body 6A. The cover body 40 is positioned above the burner cap body 30 so as to cover the burner cap body 30 and is fixed to the burner cap body 30. The burner cap body 30 is cylindrical. The burner cap body 30 is made of a metal material such as aluminum die-cast. The burner cap body 30 comprises a cylindrical cylindrical portion 31 and a flange portion 32 that protrudes from the upper end of the cylindrical portion 31.

[0039] As shown in Figure 3, the cylindrical portion 31 is configured in a cylindrical shape with a predetermined central axis G as the center of the cylinder, and extends in the direction of the central axis G. The direction of the central axis G is, for example, the vertical direction. In the example in Figure 3, the direction in which the cylindrical portion 31 extends is the vertical direction. The inner circumferential surface of the cylindrical portion 31 is configured as a cylindrical surface centered on the central axis G or an annular surface along the cylindrical surface centered on the central axis G. The outer circumferential surface of the cylindrical portion 31 is also configured as a cylindrical surface centered on the central axis G or an annular surface along the cylindrical surface centered on the central axis G. The upper end of the cylindrical portion 31 constitutes the opening at the upper end of the burner cap 20. The lower end of the cylindrical portion 31 constitutes the opening at the lower end of the burner cap 20. A through hole 36 extending vertically is formed in the central part of the burner cap body 30. The through hole 36 is configured to allow gas to pass through in the vertical direction. The inner circumference of the cylindrical portion 31 forms a through hole 36, which functions as a hole extending from the upper end to the lower end of the burner cap 20.

[0040] As shown in Figure 3, the flange portion 32 is configured as a flange-shaped portion (projection) that extends radially outward from the upper end portion of the cylindrical portion 31 with respect to the central axis G. The radial direction with respect to the central axis G is the direction that passes through and is perpendicular to the central axis G. In this specification, the radial direction with respect to the central axis G is also simply referred to as the radial direction. The flange portion 32 corresponds to an example of an annular portion. The flange portion 32 is connected to the upper end portion of the cylindrical portion 31 and is configured as a portion that extends radially outward from the upper end portion with respect to the central axis G. In the example in Figure 3, the central axis G, which is the center of the cylindrical portion 31, is the center of the flange portion. The flange portion 32 and the cylindrical portion 31 are integrally constructed from, for example, the same metal material. The flange portion 32 is provided with an upper surface portion 34. The upper surface portion 34 is the portion that constitutes the upper plate surface of the flange portion 32. The second projection 43 of the cover body 40 contacts the upper surface portion 34. The surface (upper surface) of the upper surface portion 34 is an annular surface along a plane perpendicular to the central axis G. Multiple flame hole grooves 110 are provided on the lower surface portion 35 of the flange portion 32. When the burner cap 20 is mounted on the burner body 6A as shown in Figure 3, the lower surface portion 35 of the flange portion 32 is positioned opposite the opposing surface 66A of the burner body 6A. In the mounted state shown in Figure 3, it is desirable that the lower surface portion 35 of the flange portion 32 is placed so as to contact the opposing surface 66A.

[0041] As shown in Figures 3 and 5, the cover body 40 is constructed as a circular annular plate. The cover body 40 is made of metal (for example, stainless steel). As shown in Figures 2, 3, and 5, the cover body 40 has a main body portion 41, a first projection portion 42, and a second projection portion 43. The main body portion 41, the first projection portion 42, and the second projection portion 43 of the cover body 40 are integrally formed from the same material.

[0042] As shown in Figures 3 and 5, the main body portion 41 is configured as a circular annular plate that covers the flange portion 32 of the burner cap body 30 from above. As shown in Figure 3, the first projection portion 42 is formed by bending it from the main body portion 41, for example, through metalworking (bending, etc.). The second projection portion 43 is formed by bending it from the main body portion 41, for example, through metalworking (bending, etc.). The cover body 40 is surface-treated (for example, barrel polishing, etc.) to have a smooth and glossy finish. In the center of the cover body 40, a through hole 44 is provided, which has a diameter approximately the same as the through hole 36 of the burner cap body 30, and penetrates through the main body portion 41 in the thickness direction. The through hole 44 is arranged in communication with the through hole 36 so as to continue above the internal space of the through hole 36.

[0043] As shown in Figures 3 and 5, the first projection 42 protrudes downward from the circular inner edge of the main body 41. The projection length of the first projection 42 is greater than the projection length of the second projection 43. The first projection 42 is cylindrical. The first projection 42 is inserted into the cylindrical portion 31. The first projection 42 is fixed to the cylindrical portion 31 while in contact with the inner circumference 39 of the cylindrical portion 31. Specifically, a recess 50 is provided in the inner circumference 39 of the cylindrical portion 31, and a hooking portion 47, which is part of the first projection 42, enters into the recess 50 and hooks into the recess 50, so that the first projection 42 does not come out of the cylindrical portion 31. In this configuration, the cover body 40 is fixed to the burner cap body 30.

[0044] 5. Structure near the protruding part As shown in Figure 5, the burner body 6A comprises an upper surface portion 66 having an annular opposing surface 66A facing the flange portion 32, and a recessed portion 66Z that is recessed relative to the upper surface portion 66. The opposing surface 66A is the mounting surface on which the flange portion 32 is placed. The lower surface portion 35 of the flange portion 32 contacts the opposing surface 66A. The lower surface portion 35 is the part that constitutes the lower surface of the flange portion 32. The opposing surface 66A is a mortar-shaped tapered surface, and has a shape that widens towards the top, with the diameter (diameter centered on the central axis G) increasing as it moves upward.

[0045] The recessed portion 66Z is formed on the upper surface portion 66 and on the inner circumferential wall portion 62. The recessed portion 66Z is configured as a recess that is recessed downwards on the upper surface portion 66 and as a groove that extends vertically on the inner circumferential wall portion 62. The recessed portion 66Z is a recess and groove into which the protruding portion 160 fits, and restricts the rotation of the protruding portion 160 in the circumferential direction about the central axis G when the protruding portion 160 is fitted into the recessed portion 66Z. In the mounted state where the protruding portion 160 is fitted into the recessed portion 66Z (the state in which the burner cap 20 is mounted on the burner body 6A), the protruding portion 160 is allowed to move upward while maintaining a posture along the vertical direction, but rotation in the circumferential direction and movement downward are restricted (prohibited). Therefore, the recessed portion 66Z restricts the rotation of the burner cap 20 about the central axis G when the burner cap 20 is mounted on the burner body 6A. The recess of the recessed portion 66Z spans both the upper surface portion 66 and the inner circumferential wall portion 62. The recessed portion 66Z is recessed downward from the opposing surface 66A, and in the inner circumferential wall portion 62, it is recessed radially outward.

[0046] As shown in Figures 6 and 7, the burner cap 20 comprises a plurality of flame hole grooves 110 and a projection 160. The plurality of flame hole grooves 110 are configured as grooves that allow gas to flow from the inside (towards the cylindrical portion 31) to the outside (towards the outer peripheral portion 33) on the lower surface side of the flange portion 32. The plurality of flame hole grooves 110 are provided on the lower surface portion 35 of the flange portion 32 and are configured as grooves that extend radially around the central axis G or grooves that extend in a direction slightly inclined with respect to the radial direction. Each flame hole groove 110 is a groove that allows gas to flow from the central axis G side to the outer peripheral portion 33 side, and has two walls that face each other in the circumferential direction and an upper wall, with the lower side open. Each flame hole groove 110 connects the space below the annular portion 35A and the space outside the outer peripheral portion 33, allowing gas to flow between these spaces. Each flame hole groove 110 constitutes a part of each flame hole 70. Each flame hole 70 is formed by positioning the lower surface portion 35 to block the lower part of each flame hole groove 110. Each flame hole 70 is a flow path for gas to flow from the central axis G side to the outer peripheral portion 33 side. Each flame hole 70 connects the space below the annular portion 35A and the space outside the outer peripheral portion 33, and is a flow path for gas to flow between these spaces. The gas present in the space below the annular portion 35A (the space within the mixed gas chamber 6Z) is released from the outer peripheral portion 33 through each flame hole 70.

[0047] As shown in Figures 6 and 7, the lower surface portion 35 of the flange portion 32 has an annular portion 35A that extends outward from the cylindrical portion 31 while being connected to the cylindrical portion 31, and a groove component 35B that is provided in an annular shape around the annular portion 35A. The annular portion 35A is configured in an annular shape and is a non-formed region in which no flame hole grooves 110 are formed. The groove component 35B is provided on the lower surface portion 35 between the annular portion 35A and the outer peripheral portion 33, and has a configuration with a number of protrusions that project downward. Multiple flame hole grooves 110 are arranged in a circumferential direction in a region away from the cylindrical portion 31. Each flame hole groove 110 is open on the bottom, and the opening on the bottom is closed by the opposing surface 66A. As shown in Figures 6, 7, and 10, the multiple flame hole grooves 110 include multiple main flame hole grooves 120 that, together with the opposing surface 66A, constitute the main flame hole 71; multiple flame transfer hole grooves 130 that, together with the opposing surface 66A, constitute the flame transfer flame hole 72; and multiple flame retaining hole grooves 128 that, together with the opposing surface 66A, constitute the flame retaining hole 73 (see also Figures 2 to 5, Figure 8, etc.).

[0048] Of the flame hole grooves 110, the main flame hole groove 120 is a groove that forms a path for guiding the gas supplied from the burner body 6A from the center side of the flange portion 32 outwards. As shown in Figures 2 and 3, the main flame hole groove 120 and the opposing surface 66A of the burner body 6A form the main flame hole 71. Specifically, each main flame hole 71 is formed by each main flame hole groove 120 and the upper surface portion 66. The inner wall surface of each main flame hole 71 is formed by the inner wall surface of each main flame hole groove 120 and the opposing surface 66A.

[0049] Of the flame hole grooves 110, the flame retaining hole groove 128 is a groove that forms a path for guiding the gas supplied from the burner body 6A from the center side of the flange portion 32 outwards. The vertical size (depth) of the flame retaining hole groove 128 is smaller than the vertical size (depth) of the main flame hole groove 120. As shown in Figures 2 and 4, the flame retaining hole groove 128 forms a flame retaining hole 73 between itself and the opposing surface 66A of the burner body 6A. Specifically, each flame retaining hole 73 is formed by each flame retaining hole groove 128 and the upper surface portion 66. The inner wall surface of each flame retaining hole 73 is formed by the inner wall surface of each flame retaining hole groove 128 and the opposing surface 66A.

[0050] Of the flame hole grooves 110, the flame transfer flame hole groove 130 is provided between the two main flame hole grooves 120 and forms a flame transfer flame hole 72 with the opposing surface 66A. Specifically, each flame transfer flame hole 72 is formed by each flame transfer flame hole groove 130 and the upper surface portion 66. The inner wall surface of each flame transfer flame hole 72 is formed by the inner wall surface of each flame transfer flame hole groove 130 and the opposing surface 66A. The flame transfer flame hole 72 is a flame hole that releases gas to create a flame that transfers the flame generated near one main flame hole 71 to the other main flame hole 71, which is located on both sides of itself (both sides in the circumferential direction). The size (depth) of the upper and lower grooves of the flame transfer flame hole groove 130 is smaller than the size (depth) of the upper and lower grooves of the main flame hole groove 120. Specifically, in any case of focusing on any of the flame-transferring grooves 130, the maximum depth of the flame-transferring groove 130 is smaller than the maximum depth of the main flame-transferring groove 120 closest to it on one side in the circumferential direction, and also smaller than the maximum depth of the main flame-transferring groove 120 closest to it on the other side in the circumferential direction.

[0051] As shown in Figures 6, 8, and 9, the protrusion 160 is a projection provided on the lower surface 35 so as to protrude downward. The size of the downward protrusion of the protrusion 160 is greater than the size of the downward protrusion of each wall portion constituting the multiple flame hole grooves 110. The lower end position of the protrusion 160 is lower than the lowest end position of the multiple flame hole grooves 110. The protrusion 160 is positioned to fit into the recess 66Z when the burner cap 20 is attached to the burner body 6A. When the burner cap 20 is attached to the burner body 6A, the cylindrical portion 31 is inserted into the support cylinder 76, so the movement of the cylindrical portion 31 in the radial direction (radial direction around the central axis G) is restricted. In other words, when the burner cap 20 is attached to the burner body 6A, the burner cap 20 is restricted from moving in the horizontal direction (plane direction perpendicular to the central axis G). Furthermore, because the protruding portion 160 fits into the recessed portion 66Z, the rotation of the cylindrical portion 31 around the central axis G within the support cylinder 76 is restricted, and the burner cap 20 is positioned so that it does not rotate around the central axis G.

[0052] In the examples shown in Figures 10 and 11, the first flame transfer groove 131, the second flame transfer groove 132, and the inner flame transfer groove 133 are part of a plurality of flame transfer grooves 130. The first flame transfer groove 131, the second flame transfer groove 132, and the inner flame transfer groove 133 constitute a group of flame transfer grooves radially outside the protrusion 160. This group of flame transfer grooves comprises a first wall 141 (part of the first convex portion 181) positioned on one side of the protrusion 160 in the circumferential direction of the flange portion 32, a second wall 142 (part of the second convex portion 182) positioned on the other side of the protrusion 160 in the circumferential direction, and a plurality of partition walls 144 positioned between the first convex portion 181 and the second convex portion 182 in the circumferential direction. The first flame transfer groove 131, the second flame transfer groove 132, and the inner flame transfer groove 133 are flame holes provided between the first main flame groove 120X and the second main flame groove 120Y in the circumferential direction of the flange portion 32, and release gas to create a flame that transfers the flame generated in one of them to the other. The circumferential direction of the flange portion 32 is the direction along the surface (outer surface) of the outer periphery portion 33 of the flange portion 32. For example, if a virtual plane is defined that passes through the upper end position of the multiple main flame grooves 120 (the uppermost position of the multiple main flame grooves 120) in the flange portion 32 and is perpendicular to the central axis G, and a virtual circle (the largest virtual circle if multiple virtual circles can be set) is defined on that virtual plane with the central axis G as its center and passing through the position of the surface (outer surface) of the outer periphery portion 33, then the direction of this virtual circle (circumferential direction) may be defined as the circumferential direction of the flange portion 32.

[0053] As shown in Figures 10 and 11, the multiple partition walls 144 are arranged between the first wall 141 and the second wall 142. The multiple partition walls 144 consist of one partition wall 144A and other partition walls 144B. The first flame transfer groove 131 is constructed with the one partition wall 144A and the first wall 141 as constituent elements. The first flame transfer groove 131 is a groove in which the one partition wall 144A and the first wall 141 are spaced apart from each other and has an upper wall portion (upper wall within the groove) connecting the one partition wall 144A and the first wall 141, and is configured as a flow path through which gas flows toward the outlet 131A between the one partition wall 144A and the first wall 141. Outlet 131A is the outlet of the first flame transfer groove 131 and is an outlet formed by including the radially outer end of the first wall 141 and the radially outer end of one compartment wall 144A. The second flame transfer groove 132 is formed by including another compartment wall 144B and the second wall 142 as constituent elements. The second flame transfer groove 132 is a groove in which the other compartment wall 144B and the second wall 142 are spaced apart from each other and has an upper wall portion (upper wall in the groove) connecting the other compartment wall 144B and the second wall 142, and is configured as a flow path for gas to flow toward outlet 132A between the other compartment wall 144B and the second wall 142. Outlet 132A is the outlet of the second flame transfer groove 132 and is an outlet formed by including the radially outer end of the second wall 142 and the radially outer end of the other compartment wall 144B. The inner flame transfer groove 133 is composed of one compartment wall 144A and another compartment wall 144B. The inner flame transfer groove 133 comprises a plurality of compartment walls 144. The inner flame transfer groove 133 is a groove in which one compartment wall 144A and the other compartment wall 144B are spaced apart from each other and which has an upper wall portion (upper wall within the groove) connecting the two compartment walls 144A and 144B, and is configured as a flow path through which gas flows toward the outlet 133A. The outlet 133A is the outlet of the inner flame transfer groove 133 and is an outlet provided on the outer circumference of the flange portion 32. The outlet 133A is a discharge port that includes the radially outer end of one compartment wall 144A and the radially outer end of the other compartment wall 144B.

[0054] As shown in Figures 10 and 11, the lower surface portion 35 is provided with a first protrusion 181, a second protrusion 182, a third protrusion 183, and a fourth protrusion 184.

[0055] The first protrusion 181 is a protrusion that constitutes part of the first flame transfer groove 131, part of the gas flow path 151, and part of the first main flame groove 120X. The first protrusion 181 is a protrusion that is located on one side of the projection 160 in the circumferential direction of the flange portion 32 and protrudes downward. The first protrusion 181 comprises a first wall 141 and a main flame inner wall 121A. The main flame inner wall 121A is a portion that constitutes the inner wall of the first main flame hole 120X.

[0056] The second protrusion 182 is a protrusion that constitutes part of the second flame transfer groove 132, part of the gas flow path 152, and part of the second main flame groove 120Y. The second protrusion 182 is a protrusion that is located on the other side of the projection 160 in the circumferential direction of the flange portion 32 and protrudes downward. The second protrusion 182 comprises a second wall 142 and a main flame inner wall 122A. The main flame inner wall 122 is a portion that constitutes the inner wall of the second main flame hole 120Y.

[0057] The third protrusion 183 is a protrusion located on the opposite side of the first protrusion 181 in the circumferential direction of the flange portion 32. The third protrusion 183 is spaced apart from the first protrusion 181 in the circumferential direction.

[0058] In the examples shown in Figures 10 and 11, the first main flame hole groove 120X is formed by a first protrusion 181 and a third protrusion 183. The first main flame hole groove 120X comprises a main flame hole inner wall 121A which is part of the first protrusion 181 and a main flame hole inner wall 121B which is part of the third protrusion 183, with the main flame hole inner wall 121A and the main flame hole inner wall 121B being spaced apart and facing each other in the circumferential direction. The first main flame hole groove 120X is a groove through which gas flows between the main flame hole inner wall 121A and the main flame hole inner wall 121B.

[0059] The fourth protrusion 184 is a protrusion located in the circumferential direction on the opposite side from the protruding portion of the second protrusion 182. The fourth protrusion 184 is spaced apart from the second protrusion 182 in the circumferential direction.

[0060] In the examples shown in Figures 10 and 11, the second main flame hole groove 120Y is formed by a second protrusion 182 and a fourth protrusion 184. The second main flame hole groove 120Y comprises a main flame hole inner wall 122A which is part of the second protrusion 182 and a main flame hole inner wall 122B which is part of the fourth protrusion 183, with the main flame hole inner walls 124A and 124B positioned opposite each other in the circumferential direction with a gap between them. The fourth main flame hole groove 120Y is a groove through which gas flows between the main flame hole inner wall 122A and the main flame hole inner wall 122B.

[0061] As shown in Figure 10, the first protrusion 181 protrudes downward from the third protrusion 183. Figures 11 and 12 are diagrams showing the configuration of the lower surface of the burner cap body 30 projected onto a virtual plane perpendicular to the axis G. In Figure 12, the dashed line indicated by 66Z' is the figure obtained by projecting the outer edge of the recess 66Z onto the virtual plane. The area inside the dashed line 66Z' in Figure 12 is the area of ​​the internal space of the recess 66Z. The part located inside the dashed line in Figure 12 is the part located above the internal space. In Figure 12, the line L is a radial line passing through the axis G and the center of the protrusion 160. The line M is a radial line passing through the axis G and the radially inner end of the first protrusion 181. The line N is a radial line passing through the axis G and the radially inner end of the third protrusion 183. Line P is a radial line passing through axis G and the radially inner end of the second protrusion 182. Line Q is a radial line passing through axis G and the radially inner end of the fourth protrusion 184.

[0062] As shown in Figure 12, the radially inner end 181A of the first protrusion 181 (the side closer to the center (central axis G) of the flange portion 32) is positioned closer to the center of the flange portion 32 than the radially inner end 183A of the third protrusion 183 (the side closer to the center of the flange portion 32). In other words, end 181A is closer to the center (central axis G) of the flange portion 32 than end 183A. A portion of the first protrusion 181 is positioned closer to the center of the flange portion 32 than the radially outer end 166Z of the flange portion 32 in the recess 66Z. In other words, the part of the first protrusion 181 closest to the center (central axis G) of the flange portion 32 is closer to the center of the flange portion 32 than the part of the recess 66Z furthest from the center (central axis G) of the flange portion 32. A portion of the first protrusion 181 is positioned closer to the center of the flange portion 32 than the radially outer end 160A of the flange portion 32 in the projection 160. In other words, the portion of the first protrusion 181 closest to the center of the flange portion 32 is closer to the center of the flange portion 32 than the portion of the projection 160 furthest from the center of the flange portion 32. Furthermore, a portion of the first protrusion 181 covers the internal space formed between the inner wall portion of the recess 66Z and the projection 160 from above. Specifically, the first protrusion 181 has a flat lower end surface (for example, a flat surface perpendicular to the vertical direction) at its lower end, and the first wall 141, which forms part of the side wall of the first protrusion 181, has a wall surface that is partially or entirely inclined downwards with respect to the vertical direction. In this configuration, at least a portion of the wall surface of the first wall 141 is arranged to cover the internal space formed between the inner wall portion of the recess 66Z and the projection 160 from above. More specifically, a part or all of the wall surface of the first inner wall 141A, described later, is inclined with respect to the vertical direction, and the first inner wall 141A is arranged to cover the internal space from above. At least a part of the lower end surface (e.g., flat surface) of the first protrusion 181 may also cover the internal space from above.

[0063] As shown in Figure 10, the second protrusion 182 protrudes downward more than the fourth protrusion 184. As shown in Figure 12, the radially inward end 182A of the second protrusion 182 (the side closer to the center (central axis G) of the flange portion 32) is positioned closer to the center of the flange portion 32 than the radially inward end 184A of the fourth protrusion 184 (the side closer to the center (central axis G) of the flange portion 32). In other words, end 182A is closer to the center (central axis G) of the flange portion 32 than end 184A. A portion of the second protrusion 182 is positioned closer to the center of the flange portion 32 than the radially outward end 166Z of the flange portion 32 in the recess 66Z. In other words, the part of the second protrusion 182 closest to the center (central axis G) of the flange portion 32 is closer to the center of the flange portion 32 than the part of the recess 66Z furthest from the center (central axis G) of the flange portion 32. A portion of the second protrusion 182 is positioned closer to the center of the flange portion 32 than the radially outer end 160A of the flange portion 32 in the projection 160. In other words, the portion of the second protrusion 182 closest to the center of the flange portion 32 is closer to the center of the flange portion 32 than the portion of the projection 160 furthest from the center of the flange portion 32. A portion of the second protrusion 182 covers the internal space formed between the inner wall portion of the recess 66Z and the projection 160 from above. Specifically, the second protrusion 182 has a flat lower end surface (for example, a flat surface perpendicular to the vertical direction) at its lower end, and the second wall 142, which forms part of the side wall of the second protrusion 182, has a part or all of its wall surface as an inclined surface that slopes downward with respect to the vertical direction. In this configuration, at least a portion of the wall surface of the second wall 142 is positioned to cover the internal space formed between the inner wall portion of the recess 66Z and the projection 160 from above. More specifically, a part or all of the wall surface of the second inner wall 141B, which will be described later, is inclined in the vertical direction, and the second inner wall 141B is positioned to cover the internal space from above. At least a part of the lower end surface (e.g., flat surface) of the second protrusion 182 may also cover the internal space from above.

[0064] As shown in Figures 10 and 11, the first wall 141 is a wall portion that forms part of the first protrusion 181 and is a wall portion that constitutes part of the first flame transfer groove 131. The first wall 141 comprises a first inner wall 141A, which is the inner wall on the protruding portion 160 side, and a third inner wall 141C, which is provided on the outer peripheral portion 33 side of the first inner wall 141A. The first inner wall 141A and the third inner wall 141C are arranged consecutively such that the end of the first inner wall 141A constitutes the end of the third inner wall 141C. The first inner wall 141A and the third inner wall 141C are located on the back side (opposite side in the circumferential direction) of one inner wall within the main flame groove 120X, and the first wall 141 and one inner wall within the main flame groove 120X are provided on a common projection (a projection that protrudes downward). This common projection is configured to protrude downward from the upper wall within the groove of the first flame transfer groove 131 and the upper wall within the groove of the main flame hole groove 120X. At least a portion of the first inner wall 141A faces the base end of the projection 160 in the circumferential direction.

[0065] The first gas flow path 151 is a gas flow path comprising a first convex portion 181 and a projection portion 160. Specifically, the first gas flow path 151 is comprised of a first inner wall 141A, a base end portion of the projection portion 160 (specifically, the portion of the base end portion that is on the side of the first inner wall 141A), and an upper wall portion (the upper part of the inner wall in the groove) disposed between the base end portion and the first inner wall 141A. The first gas flow path 151 is a flow path that allows gas to flow radially outward between the first inner wall 141A and the base end portion of the projection portion 160. The "base end portion of the projection portion 160" that constitutes a part of the first gas flow path 151 is the root portion of the projection portion 160, which is provided away from the first inner wall 141A and is positioned opposite the first inner wall 141A, and is the inner wall of the groove through which gas flows between it and the first inner wall 141A.

[0066] The first gas channel 151 is a gas channel leading to the first flame transfer groove 131 and the inner flame transfer groove 133, and is a channel that directs at least a portion of the gas flowing through the first gas channel 151 to the third gas channel 153. In other words, the gas flowing through the first gas channel 151 branches off and flows into the first flame transfer groove 131 and the inner flame transfer groove 133. The first inner wall 141A is inclined to approach the second wall 142 as it approaches the outer circumference 33. In the example of Figure 11, the orientation of the first inner wall 141A is such that it approaches the virtual plane L as it moves radially outward. The virtual plane L is a plane that passes through the central axis G and the center of the protrusion 160. The first gas channel 151 flows toward one of the compartment walls 144A. The third inner wall 141C is inclined to move away from the second wall 142 as it approaches the outer periphery 33. In the first fire transfer groove 131, the region where the third inner wall 141C and one compartment wall 144A face each other in the circumferential direction has a wider width (circumferential groove width) as it approaches the outer periphery 33.

[0067] The second wall 142, which constitutes a part of the second flame transfer groove 132, comprises a second inner wall 142B, which is the inner wall on the protruding portion 160 side, and a fourth inner wall 142D, which is provided on the outer peripheral portion 33 side of the second inner wall 142B. The second inner wall 142B and the fourth inner wall 142D are arranged consecutively such that the end of the second inner wall 142B constitutes the end of the fourth inner wall 142D. The second inner wall 142B and the fourth inner wall 142D are located on the back side (opposite side in the circumferential direction) of one inner wall within the groove of the main flame transfer groove 120Y, and the second wall 142 and one inner wall within the groove of the main flame transfer groove 120Y are provided on a common projection (a projection that protrudes downward). This common projection is configured to protrude downward from the upper wall within the groove of the second flame transfer groove 132 and the upper wall within the groove of the main flame transfer groove 120Y. At least a portion of the second inner wall 142B faces the base end of the projection 160 in the circumferential direction.

[0068] The second gas passage 152 is a gas passage comprising a second convex portion 182 and a protruding portion 160. The second gas passage 152 is comprised of a second inner wall 142B, a base end portion of the protruding portion 160 (specifically, the portion of the base end portion that is on the side of the second inner wall 142B), and an upper wall portion (the upper part of the inner wall in the groove) positioned between the base end portion and the second inner wall 142B, and is a passage that allows gas to flow radially outward between the second inner wall 142B and the base end portion of the protruding portion 160. The "base end portion of the protruding portion 160" which constitutes a part of the second gas passage 152 is the root portion of the protruding portion 160, which is provided away from the second inner wall 142B and positioned opposite the second inner wall 142B, and is the inner wall of the groove through which gas flows between it and the second inner wall 142B.

[0069] The second gas channel 152 is a gas channel leading to the second flame transfer groove 132 and the inner flame transfer groove 133, and is a channel that directs at least a portion of the gas flowing through the second gas channel 152 to the third gas channel 153. In other words, the gas flowing through the second gas channel 152 branches off and flows into the second flame transfer groove 132 and the inner flame transfer groove 133. The second inner wall 142B is inclined to approach the first wall 141 as it approaches the outer periphery 33. In the example in Figure 11, the orientation of the second inner wall 142B is such that it approaches the virtual plane L as it moves radially outward. The second gas channel 152 flows toward the other compartment wall 144B. The fourth inner wall 142D is inclined to move away from the first wall 141 as it approaches the outer periphery 33. In the second fire transfer groove 132, the region where the fourth inner wall 142D and the other compartment wall 144B face each other in the circumferential direction has a wider width (circumferential groove width) as it approaches the outer periphery 33.

[0070] The distance between the first inner wall 141A and the second inner wall 142B (distance in the direction perpendicular to the virtual plane L) narrows as it approaches the outer perimeter 33. The distance between the third inner wall 141C and the fourth inner wall 142D (distance in the direction perpendicular to the virtual plane L) widens as it approaches the outer perimeter 33.

[0071] The outer circumference 33 of the flange portion 32 is provided with outlets 131A, 132A, and 133A for the first flame transfer groove 131, the second flame transfer groove 132, and the inner flame transfer groove 133, respectively.

[0072] As shown in Figures 9 to 11, a stepped portion 170 is provided between the protruding portion 160 and the multiple partition walls 144. As shown in Figures 10 and 11, the stepped portion 170 and the multiple partition walls 144 form a third gas passage 153 that guides the gas flowing through the first gas passage 151 and the second gas passage 152 to the inner flame transfer hole groove 133. The third gas passage 153 is configured to include a protruding portion and multiple partition walls. The third gas passage 153 directs at least a portion of the gas flowing through the third gas passage 153 to the inner flame transfer hole groove 133.

[0073] The stepped portion 170 is a stepped structure provided between the protruding portion 160 and the multiple partition walls 144. The stepped portion 170 covers the internal space formed between the inner wall portion of the recessed portion 66Z and the protruding portion 160 from above.

[0074] 6. Examples of effects The gas stove 1 described above, due to the positional relationship between the first protrusion 181 and the second protrusion 182, can prevent the space near the recess 66Z (especially the space near both sides of the recess 66Z in the circumferential direction) from becoming too large. Therefore, this gas stove 1 can be less prone to problems caused by the unexpected large space near the recess 66Z (such as excessive gas supply beyond the design assumption).

[0075] Furthermore, in this gas stove 1, since a portion of each of the first protrusion 181 and the second protrusion 182 covers the internal space formed between the inner wall of the recess 66Z and the protrusion 160 from above, it is possible to suppress the large amount of gas flowing near the protrusion 160 into the vicinity of the recess 66Z or the large amount of gas flowing out from within the recess 66Z. Therefore, this gas stove 1 is able to easily suppress the excessive flow of gas through the vicinity of the recess 66Z to the first flame transfer hole groove 131 and the second flame transfer hole groove 132.

[0076] Specifically, the first protrusion 181 has a flat lower end surface (for example, a flat surface perpendicular to the vertical direction) at its lower end, and this lower end surface is in contact with the opposing surface 66A (mounting surface) of the burner body 6A and is supported from below by the opposing surface 66A. On the other hand, the first wall 141, which forms part of the side wall of the first protrusion 181, has a part or all of its wall surface as an inclined surface that slopes downward with respect to the vertical direction. At least a part of the wall surface of the first wall 141 is positioned to cover the internal space formed between the inner wall of the recess 66Z and the protrusion 160 from above. More specifically, part or all of the wall surface of the first inner wall 141A is an inclined wall surface with respect to the vertical direction (specifically, an inclined surface that slopes downward with respect to the vertical direction from the upper wall inside the groove of the first gas passage 151 toward the lower end surface of the first protrusion 181), and the first inner wall 141A is arranged to cover the internal space from above. Therefore, even if there is a slight deviation from the design configuration due to molding errors in the burner body 6A or some other reason, excessive gas flow from the internal space into the first gas passage 151 is suppressed.

[0077] Similarly, the first protrusion 182 has a flat lower end surface (for example, a flat surface perpendicular to the vertical direction) at its lower end, and this lower end surface is in contact with the opposing surface 66A (mounting surface) of the burner body 6A and is supported from below by the opposing surface 66A. On the other hand, the second wall 142, which forms part of the side wall of the second protrusion 182, has a part or all of its wall surface as an inclined surface that slopes downward with respect to the vertical direction. At least a part of the wall surface of the second wall 142B is positioned to cover the internal space formed between the inner wall of the recess 66Z and the protrusion 160 from above. More specifically, part or all of the wall surface of the second inner wall 141B is an inclined wall surface with respect to the vertical direction (specifically, an inclined surface that slopes downward with respect to the vertical direction from the upper wall inside the groove of the second gas passage 152 toward the lower end surface of the second protrusion 182), and the second inner wall 142B is positioned to cover the internal space from above. Therefore, even if there is a slight deviation from the design configuration due to molding errors of the burner body 6A or some other reason, excessive gas flow from the internal space into the second gas passage 152 is suppressed.

[0078] Furthermore, the gas stove 1 can position the first protrusion 182 lower and more radially inward in relation to the third protrusion 183, and the second protrusion 182 lower and more radially inward in relation to the fourth protrusion 184. Therefore, the gas stove 1 can ensure gas flow through the first gas passage 151 and the second gas passage 152, while more reliably preventing excessive gas flow into the first flame transfer hole groove 131 and the second flame transfer hole groove 132.

[0079] In the gas stove 1, a portion of each of the first protrusion 181 and the second protrusion 182 is positioned closer to the center of the flange portion 32 than the radially outer end of the flange portion 32 in the protruding portion 160. Therefore, even if manufacturing errors occur, it is possible to prevent the space between the protrusion 160 and each protrusion from becoming too large near the recessed portion 66Z, thereby suppressing "excessive gas flow caused by this space becoming too large."

[0080] In the gas stove 1, the gas that has flowed through the first gas channel 151 and the second gas channel 152 can be directed not only to the first flame transfer groove 131 and the second flame transfer groove 132, but also to the inner flame transfer groove 133 due to the presence of the third gas channel 153. Therefore, in this gas stove 1, the dispersion of gas is increased, and localized gas concentration can be further suppressed.

[0081] The gas stove 1 can prevent gas flowing near the protruding portion 160 from flowing into the recessed portion 66Z due to the presence of the stepped portion 170. In this gas stove 1, the first convex portion 181, the second convex portion 182, and the stepped portion 170 work synergistically in the vicinity of the recessed portion 66Z, making it even easier to suppress excessive gas flow from the vicinity of the recessed portion 66Z to the vicinity of the flame transfer hole groove outside of it.

[0082] <Other Embodiments> The present invention is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.

[0083] In the above description of the embodiment, a gas stove 1 configured as a built-in stove was given as an example of a stove, but the stove may be other types such as a table stove.

[0084] In the above-described embodiment, the multiple partition walls 144 were composed of one partition wall 144A and another partition wall 144B, but three or more partition walls may be provided spaced apart in the circumferential direction. In this case, two or more inner flame transfer grooves may be provided, each formed by adjacent partition walls in the three or more partition walls.

[0085] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope set forth in the claims or equivalents thereof. [Explanation of symbols]

[0086] 1: Gas stove 4: Gas burner 5: Gas burner 6: Gas burner 6A: Burner body 20: Burner Cap 21: Burner Cap 22: Burner Cap 31:Cylinder part 32: Flange section 33: Outer periphery 35: Bottom part 66:Top part 66A: Opposite surface 66Z: Recessed area 70 flame hole 71 Main flame hole 72. Fire-spreading flame holes 110 Flame hole groove 120 Main flame hole groove 130 Flame-transferring grooves 131 First fire-transferring flame hole groove 131A Exit 132 Second Flame Transfer Hole Groove 132A Exit 133 Inner flame transfer hole groove 133A Exit 144 partition wall 144A Partition wall 144B Other partition walls 151 First gas flow path 152 Second gas flow path 153 Third gas channel 160 Protrusion 170 Step section 181 First protrusion 182 Second protrusion 183 Third protrusion 184 Fourth protrusion

Claims

1. a burner body for supplying gas; a burner cap having a cylindrical portion and a flange portion extending from the cylindrical portion and attached to the burner body; A gas stove having The burner body includes an upper surface portion having an annular opposing surface opposing the flange portion, and a recessed portion recessed relative to the upper surface portion, The burner cap includes a plurality of flame hole grooves provided on a lower surface of the flange portion, and a protrusion provided on the lower surface and inserted into the recessed portion, The plurality of flame hole grooves include a plurality of main flame hole grooves which, together with the opposing surface, form main flame holes, and a plurality of flame transfer flame hole grooves which, together with the opposing surface, form flame transfer flame holes, The lower surface portion is provided with a first convex portion that is disposed on one side of the protruding portion in the circumferential direction of the flange portion and that protrudes downward, a second convex portion that is disposed on the other side of the protruding portion in the circumferential direction and that protrudes downward, and a plurality of partition walls that are disposed between the first convex portion and the second convex portion in the circumferential direction, a first gas flow path is formed by the first convex portion and the protruding portion, a second gas flow path is formed by the second convex portion and the protruding portion, a first fire-transfer flame hole groove among the plurality of fire-transfer flame hole grooves includes a first wall forming a part of the first protrusion and one of the plurality of partition walls; a second fire-transfer flame hole groove among the plurality of fire-transfer flame hole grooves includes a second wall forming a part of the second protrusion and another partition wall among the plurality of partition walls; The flange portion has an outer periphery provided with outlets of the first flame transfer groove and the second flame transfer groove, A portion of each of the first protrusion and the second protrusion is disposed closer to the center of the flange portion than the radially outer end of the flange portion in the recess. Gas stove.

2. A part of each of the first convex portion and the second convex portion covers from above an internal space defined between an inner wall portion of the recess portion and the protrusion portion.

2. The gas stove according to claim 1.

3. a third convex portion is provided on the opposite side of the first convex portion from the protruding portion in the circumferential direction, a fourth convex portion is provided on the opposite side of the second convex portion from the protruding portion in the circumferential direction, a first main flame hole groove is formed by the first convex portion and the third convex portion, a second main flame hole groove is formed by the second convex portion and the fourth convex portion, the first protrusion protrudes downward further than the third protrusion, the second protrusion protrudes downward further than the fourth protrusion, a radially inner end of the first protrusion is disposed closer to the center of the flange portion than a radially inner end of the third protrusion, A radially inner end of the second protrusion is disposed closer to the center of the flange than a radially inner end of the fourth protrusion.

3. A gas stove according to claim 1 or claim 2.

4. A portion of each of the first convex portion and the second convex portion is disposed closer to the center of the flange portion than an outer end of the flange portion in the radial direction. A gas stove according to any one of claims 1 to 3.

5. Among the plurality of fire transfer flame hole grooves, the inner fire transfer flame hole groove has the plurality of partition walls, An outlet of the inner flame transfer flame hole groove is provided on the outer periphery of the flange portion, a third gas flow path is formed by the protrusion and the plurality of partition walls, the first gas flow passage causes at least a portion of the gas flowing through the first gas flow passage to flow into the third gas flow passage; the second gas flow path causes at least a portion of the gas flowing through the second gas flow path to flow into the third gas flow path; The third gas flow passage causes at least a portion of the gas flowing through the third gas flow passage to flow into the inner flame transfer flame hole groove. A gas stove according to any one of claims 1 to 4.

6. a step portion is provided between the protrusion and the plurality of partition walls, The step portion covers from above an internal space defined between an inner wall portion of the recess portion and the protrusion portion. A gas stove according to any one of claims 1 to 5.

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