201219723 六、發明說明： 【發明所屬>=5^技^領域；J 發明領域 本發明係有關於一種瓦斯爐，且該瓦斯爐包含有：爐 具本體；頂板，係覆蓋該爐具本體之上面者；及瓦斯燃燒 器’係透過業已形成於該頂板之燃燒器用開口，使一部分 露出者。 C ϋ 發明背景 以往，於瓦斯爐中，為了不讓溢出的湯汁或異物自頂 板之燃燒器用開口與瓦斯燃燒器間侵入爐具本體内部，會 設置可閉塞燃燒器用開口與瓦斯燃燒器間之閉塞板（例如 參照專利文獻1)。 此種閉塞板係透過襯墊而栽置於頂板之燃燒器用開口 之周緣部’並設置成可自由拆卸。 先行技術文獻 專利文獻 專利文獻1日本專利公開公報特開2004-93056號公報 【潑h明内容】 發明概要 發明欲解決之課題 然而，由於習知閉塞板係載置於頂板上之構造，因此， 相對於瓦斯燃燒器或頂板亦容易產生錯位，不僅閉塞狀態 足外觀上亦不理想。又，在清掃等之保養時可容易地 201219723 自頂板輕易地卸下，另一方面，在燃燒器本體之清掃等之 保養時燃燒器用開口會開放，因此，會有異物掉落、侵入 爐具本體内部之虞。 有鑑於前述情形，本發明之目的係提供一種瓦斯爐， 且該瓦斯爐可確實地閉塞混合管之下游端部與頂板之燃燒 器用開口間，並可取得良好之外觀且生產性亦高。 用以欲解決課題之手段 本發明係一種瓦斯爐，且該瓦斯爐包含有：爐具本體； 頂板，係覆蓋該爐具本體之上面者；及瓦斯燃燒器，係透 過業已形成於該頂板之燃燒器用開口，使一部分露出者； 又，前述瓦斯燃燒器包含有：混合管，係使下游端部面對 前述燃燒器用開口者；及燃燒器本體，係於前述頂板上露 出者；並且，使突設於燃燒器本體之下面中央部之筒狀混 合氣流入部嵌合於混合管之下游端，並將來自混合管之混 合氣供給至燃燒器本體，又，將閉塞板設置成與前述燃燒 器本體呈同心地連結於前述混合管，且前述閉塞板係遍及 全周地將形成於前述混合管之下游端部之外周壁與燃燒器 用開口之周緣間的環狀間隙閉塞。 若藉由本發明，則將閉塞板連結於混合管，藉此，即 使自混合管卸下燃燒器本體，閉塞板亦可維持混合管與燃 燒器用開口間之閉塞狀態，因此，可確實地防止在燃燒器 本體之清掃等之保養時，異物透過燃燒器用開口而掉落、 侵入爐具本體内部。 又，藉由將閉塞板連結於混合管，即使組裝於混合管 4 201219723 之燃燒器本體與頂板之燃燒器用開口產生軸心偏離，閉塞 板亦可確實地閉塞燃燒器用開口，並可防止異物或溢出的 湯汁侵入爐具本體内部。又，藉由使閉塞板閉塞燃燒器用 開口，爐具本體與燃燒器用開口之錯位不會露出，並可防 止外觀之降低。再者，無需如習知般用以沿著頂板之燃燒 器用開口之内周緣固定閉塞板之機構，且零件數亦少，同 時由於組裝容易，因此生產性亦高。 又，於本發明中，前述閉塞板宜形成為自其外周朝混 合管之下游端部逐漸地增加高度之形狀。藉此，當沿著頂 板之上面流動的燃燒用二次空氣朝向燃燒器本體時，會藉 由閉塞板朝上升方向導引，故，可將二次空氣順利地供給 至燃燒中的燃燒器本體，並可取得瓦斯燃燒器良好之燃 燒。又，溢出的湯汁不會積存於閉塞板上，並可防止因髒 污附著於閉塞板所造成的外觀之降低，且由於髒污之擦拭 作業亦容易，因此清掃等之保養性亦佳。 又，於本發明中，宜於自前述頂板露出之燃燒器本體 之周圍設置火架，且該火架係定位成其下部内側面嵌合於 前述閉塞板之外周部。由於火架係構成藉由閉塞板定位之 狀態，因此，可使燃燒器本體之軸心與火架之軸心一致， 並可將相對於燃燒器本體之火架之位置維持於良好之狀態。 再者，前述火架宜載置於前述閉塞板。藉此，不會因 爐具本體之應變或頂板之應變等而受到業已支持於爐具本 體之瓦斯燃燒器與頂板之相對高度之變形之影響，並可將 相對於燃燒器本體之火架之高度維持一定。 201219723 又’於本發明中’前述閉塞板宜為其外周部下面透過 襯墊而抵接於沿著燃燒器用開口周緣之頂板上面，且1述 襯墊係設置成當前述閉塞板位於非抵接狀態時，可相胃& 前述頂板而自由移動。 一般而言，瓦斯燃燒器係安裝支持於爐具本體，然而， 由於瓦斯燃燒器於爐具本體之安裝誤差’會有燃燒器本體 相對於頂板之燃燒器用開口而發生軸心偏離之情形。此 時’當襯塾嵌合、安裝於燃燒器用開口之内周緣時，相對 於襯墊，閉塞板會發生錯位。故，不僅無法藉由襯墊充分 地封裝閉塞板與燃燒器用開口間，且襯墊之一部分係自閉 塞板露出而有外觀降低之虞。 故，於本發明中，藉由將閉塞板位於非抵接狀態時的 襯墊作成可自由移動，即使產生燃燒器用開口與燃燒器本 體之軸心偏離，襯墊亦會按照其偏離尺寸而移動，因此， 不會受到軸心偏離之影響，並可確實地密封閉塞板與燃燒 器用開口間，且亦可防止外觀之降低。 圖式簡單說明 第1圖係本發明之實施形態之瓦斯爐之局部平面圖。 第2圖係本實施形態之瓦斯爐之主要部分截面圖。 第3圖係顯示本實施形態之瓦斯爐所具有的瓦斯燃燒 器之立體圖。 【 用以實施發明之形態、 以下，參照圖式，說明本發明之實施形態。如第1及2 6 201219723 圖中顯示主要部分，本實施形態之瓦斯爐係具有瓦斯燃燒 器1 ;及設置於瓦斯燃燒器1周圍的火架2。 瓦斯燃燒器1包含有：燃燒器本體4，係於構成瓦斯爐 之一部分的頂板3上露出者；及混合管8，係於構成瓦斯爐 之另一部分的爐具本體5之内部，透過台座部7連結固定於 底板6者。混合管8之下游端部8a係朝上方開口。 如第2圖所示，頂板3係設置成覆蓋爐具本體5之上面， 並藉由頂板本體1〇及閉塞板丨丨所構成，且前述頂板本體1〇 係形成直徑大於燃燒器本體4之燃燒器用開口9，前述閉塞 板11係覆蓋頂板本體10之燃燒器用開口 9。頂板本體1 〇係藉 由金屬板或玻璃板平坦地形成，閉塞板丨丨則藉由金屬板來 形成。 閉塞板11係於中央部開設可插裝混合管8之下游端部 a之插裝孔12 ^又，閉塞板Η係形成為自其外周朝混合管8 之下/玲端部8a透過落差而逐漸地增加高度之形狀。 、藉此，於調理時溢出的湯汁不會積存而可流向外周， 並可防止因髒污附著所造成的外觀之降低，且由於髒污之 擦拭作業亦料，因此清料之料性亦佳。 社]塞板11雖構成頂板3之一部分，但並未與頂板3連 8 藉由螺絲構件13，連結固定於瓦斯燃燒器1之混合管 閉塞板11係形成為在將混合管8之下游端部仏插裝於插 裝孔12時，構成與燃燒器本體4呈同心之圓形。 閉塞板11之外周部下面係透過襯墊14，抵接於依循著 °開口 9周緣之頂板本體10之上面。襯墊14係藉由以 201219723 下所構成，即·密封部14a’係密接於頂板本體1〇之上面者； 凸緣部14b，係朝該密封部14a之外周伸出，並抵接閉塞板 11之外周緣者；及垂下部14c，係自密封部14a之内周朝下 方延伸者。襯墊14之垂下部14c之外徑會稍微小於燃燒器用 開口 9之内徑，且於閉塞板丨丨與密封部14a位於非抵接狀態 時（即’閉塞板11之組裝前之狀態），構成可相對於前述頂板 本體10而自由移動。 藉此’舉例言之，即使因混合管8於爐具本體5之底部6 的安裝位置之誤差，產生組裝於混合管8之燃燒器本體4與 頂板3之燃燒器用開口9之軸心偏離，燃燒器用開口9之内周 緣亦藉由閉塞板11之外周部來隱藏，因此，可防止外觀之 降低。又，刖述襯塾14係其垂下部i4c之外徑稍微小於燃燒 器用開口9之内徑，並構成可相對於頂板本體1〇而自由移 動。故，即使連結於混合管8之閉塞板丨丨與燃燒器用開口9 產生軸心偏離，襯墊14亦會按照其偏離尺寸而移動，並可 確實地密封閉塞板11之外周部下面與依循著燃燒器用開口 9周緣之頂板本體1〇之上面間。 火架2係由環狀之火架框23及5個火架爪孔所構成，且 该火架爪2b係於該火架框23之周方向隔著預定間隔而固定 支持。火架框2a係嵌合於業已形成於閉塞板n外周部之落 差，並於業經定位之狀態下載置於閉塞板U上。 即’火架2係構成透過閉塞板丨丨而载置於混合管8之狀 態。藉此，可使組裝於混合管8之燃燒器本體4之軸心與火 架2之軸心一致。再者，即使於爐具本體5發生應變等而改 8 201219723 變頂板本體ίο與底部6之距離’火架2亦藉由載置於業已連 結於混合管8之閉塞板11，而可將燃燒器本體4與載置於火 架2上之鍋底之間隔距離維持一定。 另，雖未圖示，然而，即使火架係載置於頂板本體1〇 上之形狀者，藉由使環狀之火架框之内周面嵌合於閉塞板 11之外周部，而可使燃燒器本體之軸心與火架之軸心一 致。又，舉例言之，在各火架爪之下端緣係構成載置面之 火架時，亦可將各火架爪之下部内側面嵌合於閉塞板11之 外周部。 燃燒器本體4係具有母燃燒器部15及子燃燒器部16而 構成所謂子母燃燒器。如第3圖所示，混合管8包含有：母 燃燒器用混合管部17 ’係將混合氣體供給至母燃燒器部15 者；及子燃燒器用混合管部18 ’係將混合氣體供給至子燃 燒器部16者。 如第2圖所示，混合管8之下游端部8a係於母燃燒器用 混合管部17之内側收納子燃燒器用混合管部18而作成二重 管結構。 如第1及2圖所示，燃燒器本體4係藉由燃燒器主體19及 一對燃燒器頭（母燃燒器頭20及子燃燒器頭21)所構成。燃燒 器主體19係於其外側形成母燃燒器部15之分布室22，並於 内側形成子燃燒器部16之分布室23。藉由於母燃燒器部15 之分布室22上載置母燃燒器頭2〇 ’於母燃燒器部丨5之外周 形成複數母燃燒器焰孔24 ’且藉由於子燃燒器部16之分布 室23上載置子燃燒器頭21，於子燃燒器部16之外周形成複 201219723 數子燃燒器焰孔25。 又’於燃燒1§主體19之下面中央部，對應於混合管仏 下游端部8a而設置筒狀之混合氣流入部26。如第2圖所示， 混合氣流入部26係藉由位於外側之母燃繞器用通路π及其 内側之子燃燒關通路28所構成^若混合氣流入部減合 於混合管8之下游端部Sa，則母燃燒器用通路η係與母燃燒 器用混合管部Π連通，同時子燃燒器用通物係與子燃燒 器用混合管部18連通。另，混合氣流入部％係嵌合於混合 管8之下游端部8a且可自由裝卸，並構成在清掃等之保養時 可輕易地自混合管8卸下燃燒器本體4。 又，如第2圖所示，混合氣流入部26係配置於燃燒器主 體19之子燃燒器部16之下部位置，因此，如第1及2圖所示， 母燃燒器用通路27係藉由自子燃燒器部16側呈放射狀延伸 之聯絡管部29，與母燃燒器部15之分布室22連通。 又’未圖示之氣體喷嘴係面對前述混合管8之母燃燒器 用混合管部17與子燃燒器用混合管部18各自之上游端。若 自氣體噴嘴噴出燃料氣，則隨著燃料氣之噴出，吸引一次 空氣，並生成混合氣體。 如第2圖所示，於母燃燒器頭20之一部分形成點火靶 30。點火靶30係與業已透過支持構件31支持於混合管8之點 火塞32之前端相對，並接受點火塞32之放電而對母燃燒器 部15點火。點火塞32係貫通閉塞板11而朝上方延伸。另， 於第1圖中以符號33所示者係檢測子燃燒器部16之著火的 熱電偶。雖未圖示，然而，熱電偶33亦與點火塞32相同地 10 201219723 支持於混合管8，並貫通閉塞板11而朝上方延伸。 如第1及3圖所示，藉由母燃燒器部15所形成的火焰係 透過業已形成於母燃燒器頭20之移火用狹縫20a而移火至 子燃燒器部16，藉此，子燃燒器部16會點火。藉由子燃燒 器部16所形成的火焰係自前述聯絡管部29間之空隙供給二 次空氣。此時，閉塞板11係形成為自其外周朝混合管8之下 游端部8a透過落差而逐漸地增加高度之形狀，藉此，形成 自頂板之上面朝燃燒器本體4上升之二次空氣流。故，不僅 是母燃燒器部15，於子燃燒器部16亦可供給充分量之二次 空氣，並可取得良好之燃燒狀態。 另，於本實施形態中，顯示瓦斯燃燒器1係具有母燃燒 器部15及子燃燒器部16者，然而，雖未圖示，但只要是混 合管嵌合於燃燒器本體之中央部之構造的瓦斯燃燒器，則 即使是具有單一燃燒器部之瓦斯燃燒器，亦可適當地採用 本發明。 【圖式簡單說明】 第1圖係本發明之實施形態之瓦斯爐之局部平面圖。 第2圖係本實施形態之瓦斯爐之主要部分截面圖。 第3圖係顯示本實施形態之瓦斯爐所具有的瓦斯燃燒 器之立體圖。 【主要元件符號說明】 1.. .瓦斯燃燒器 2b...火架爪 2.. .火架 3...頂板 2a...火架框 4...燃燒器本體 11 201219723 5.. .爐具本體 6 · _ · 板 7.. .台座部 8.. .混合管 8a...下游端部 9.. .燃燒器用開口 10.. .頂板本體 11.. .閉塞板 12.. .插裝孔 13.. .螺絲構件 14···襯塾 14a.·.密封部 14b...凸緣部 14c...垂下部 15.. .母燃燒器部 16.. .子燃燒器部 17.. .母燃燒器用混合管部 18.. .子燃燒器用混合管部 19.. .燃燒器主體 20.. .母燃燒器頭 20a...狹縫 21.. .子燃燒器頭 22，23...分布室 24.. .母燃燒器焰孔 25.. .子燃燒器焰孔 26.. .混合氣流入部 27.. .母燃燒器用通路 28.. .子燃燒器用通路 29.. .聯絡管部 30.. .點火乾 31.. .支持構件 32.. .點火塞 33.. .熱電偶 12201219723 VI. Description of the invention: [Invention] The field of the invention relates to a gas furnace, and the gas furnace comprises: a stove body; a top plate covering the body of the stove The upper part; and the gas burner' pass through the burner opening which has been formed in the top plate to expose a part of the burner. C ϋ BACKGROUND OF THE INVENTION In the gas furnace, in order to prevent the overflowing soup or foreign matter from invading the inside of the furnace body from the burner opening of the top plate and the gas burner, a closable burner opening and a gas burner are provided. The occlusion plate (for example, refer to Patent Document 1). The occluding plate is placed on the peripheral edge portion of the burner opening of the top plate through the gasket and is detachably provided. CITATION LIST Patent Literature PATENT DOCUMENT PATENT DOCUMENT PATENT DOCUMENT LIST OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION However, since the conventional occlusion plate is placed on the top plate, It is also prone to misalignment with respect to the gas burner or the top plate, and not only the occlusion state is not ideal in appearance. In addition, it is easy to remove from the top plate in 201219723 during maintenance such as cleaning. On the other hand, the burner opening is opened during maintenance such as cleaning of the burner body, so that foreign matter may fall and invade the stove. The inside of the body. In view of the foregoing, it is an object of the present invention to provide a gas burner which can positively block the downstream end portion of the mixing tube and the burner opening of the top plate, and which can achieve a good appearance and high productivity. Means for solving the problem The present invention is a gas furnace, and the gas furnace comprises: a stove body; a top plate covering the upper surface of the stove body; and a gas burner, which is formed through the top plate The burner has an opening to expose a part of the burner; and the gas burner includes: a mixing tube that faces the downstream end of the burner; and a burner body that is exposed on the top plate; and a cylindrical mixed airflow portion protruding from a central portion of the lower portion of the burner body is fitted to a downstream end of the mixing pipe, and a mixed gas from the mixing pipe is supplied to the burner body, and the blocking plate is further disposed with the burner The main body is concentrically coupled to the mixing tube, and the blocking plate is closed over the entire circumference by an annular gap formed between the outer peripheral wall of the downstream end portion of the mixing tube and the periphery of the burner opening. According to the present invention, the closing plate is coupled to the mixing tube, whereby the closing plate can maintain the closed state between the mixing tube and the burner opening even if the burner body is removed from the mixing tube, so that it can be reliably prevented. When the burner body is cleaned or the like, the foreign matter is dropped through the opening of the burner and is invaded into the inside of the stove body. Further, by connecting the blocking plate to the mixing tube, even if the burner body assembled in the mixing tube 4 201219723 and the burner opening of the top plate are axially offset, the blocking plate can surely close the burner opening and prevent foreign matter or The overflowing soup invades the inside of the stove body. Further, by closing the opening of the burner with the closing plate, the misalignment of the opening of the cooker body and the burner is not exposed, and the appearance can be prevented from being lowered. Further, there is no need to use a mechanism for fixing the occlusion plate along the inner periphery of the burner opening of the top plate as is conventionally known, and the number of parts is small, and the productivity is also high because assembly is easy. Further, in the invention, it is preferable that the occlusive plate is formed in a shape which gradually increases in height from the outer periphery toward the downstream end portion of the mixing tube. Thereby, when the secondary air for combustion flowing along the upper surface of the top plate faces the burner body, it is guided in the ascending direction by the blocking plate, so that the secondary air can be smoothly supplied to the burner body in combustion. And can get good combustion of gas burner. Further, the overflowed soup is not accumulated on the occlusion plate, and the appearance of the smear due to dirt adhering to the occlusion plate can be prevented from being lowered, and the wiping operation by the dirt is easy, so that the maintenance property such as cleaning is also good. Further, in the invention, it is preferable that a fire holder is provided around the burner body exposed from the top plate, and the fire frame is positioned such that a lower inner side surface thereof is fitted to an outer peripheral portion of the blocking plate. Since the flame frame is positioned by the occlusion plate, the axis of the burner body can be aligned with the axis of the flame frame, and the position of the flame frame relative to the burner body can be maintained in a good state. Furthermore, the fire frame is preferably placed on the occlusion plate. Thereby, the deformation of the relative height of the gas burner and the top plate which has been supported by the main body of the furnace is not affected by the strain of the main body or the strain of the top plate, etc., and the flame frame relative to the burner body can be The height is maintained at a certain level. 201219723 In the present invention, the occlusion plate is preferably such that the outer peripheral portion thereof is in contact with the top plate of the periphery of the burner opening through the gasket, and the spacer is disposed such that the occlusion plate is non-contacted. In the state, it can move freely with the stomach and the top plate. In general, the gas burner is mounted to support the furnace body, however, due to the installation error of the gas burner in the furnace body, there is a case where the burner body is axially offset with respect to the burner opening of the top plate. At this time, when the lining is fitted and attached to the inner periphery of the burner opening, the damper plate is displaced relative to the spacer. Therefore, it is not only impossible to sufficiently enclose the gap between the closing plate and the burner opening by the gasket, and one of the gaskets is exposed from the closing plate to have a reduced appearance. Therefore, in the present invention, the spacer is freely movable by the spacer in the non-contact state, and even if the burner opening is deviated from the axis of the burner body, the spacer moves according to the deviation dimension. Therefore, it is not affected by the deviation of the axial center, and the sealing plate and the opening for the burner can be reliably sealed, and the appearance can be prevented from being lowered. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial plan view showing a gas furnace of an embodiment of the present invention. Fig. 2 is a cross-sectional view showing the main part of the gas burner of the present embodiment. Fig. 3 is a perspective view showing a gas burner included in the gas burner of the embodiment. [Embodiment for Carrying Out the Invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in Figs. 1 and 2, 201219723, the gas furnace of the present embodiment has a gas burner 1 and a flame frame 2 provided around the gas burner 1. The gas burner 1 comprises: a burner body 4 which is exposed on a top plate 3 constituting a part of the gas furnace; and a mixing pipe 8 which is inside the furnace body 5 constituting another part of the gas furnace and passes through the pedestal portion 7 is fixed to the bottom plate 6. The downstream end portion 8a of the mixing tube 8 is opened upward. As shown in FIG. 2, the top plate 3 is disposed to cover the upper surface of the cooker body 5, and is constituted by a top plate body 1 and a closed plate, and the top plate body 1 is formed to have a larger diameter than the burner body 4. The burner opening 9 covers the burner opening 9 of the top plate body 10. The top plate body 1 is formed flat by a metal plate or a glass plate, and the closed plate is formed by a metal plate. The occlusion plate 11 is formed in the central portion to open the insertion hole 12 of the downstream end portion a of the insertable mixing tube 8. Further, the occlusion plate is formed so as to be permeable from the outer circumference toward the lower portion of the mixing tube 8/the end portion 8a. Gradually increase the shape of the height. Therefore, the soup overflowing during conditioning does not accumulate and can flow to the outer circumference, and can prevent the appearance of the dirt due to the adhesion of dirt, and the wiping operation due to dirt is also expected. good. The plug plate 11 constitutes a part of the top plate 3, but is not connected to the top plate 3, and is connected to the gas burner 1 by the screw member 13, and the mixing tube closing plate 11 is formed at the downstream end of the mixing tube 8. When the cartridge is inserted into the insertion hole 12, it is formed in a circular shape concentric with the burner body 4. The outer peripheral portion of the occluding plate 11 is passed through the spacer 14 so as to abut against the upper surface of the top plate body 10 which follows the circumference of the opening 9. The gasket 14 is constructed by 201219723, that is, the sealing portion 14a' is in close contact with the upper surface of the top plate body 1; the flange portion 14b extends toward the outer periphery of the sealing portion 14a and abuts the blocking plate. The outer periphery of the seal portion 14 and the lower portion 14c extend downward from the inner circumference of the seal portion 14a. The outer diameter of the lower portion 14c of the gasket 14 is slightly smaller than the inner diameter of the burner opening 9, and when the occlusion plate 丨丨 and the sealing portion 14a are in a non-contact state (ie, the state before the assembly of the occlusion plate 11), The configuration is free to move relative to the top plate body 10 described above. By way of example, even if the mixing tube 8 is at the mounting position of the bottom portion 6 of the oven body 5, the axial center deviation of the burner opening 4 assembled to the mixing tube 8 and the burner opening 9 of the top plate 3 is generated. The inner circumference of the burner opening 9 is also hidden by the outer peripheral portion of the closing plate 11, so that the appearance can be prevented from being lowered. Further, the lining 14 is described as having an outer diameter of the hanging portion i4c which is slightly smaller than the inner diameter of the burner opening 9, and is configured to be freely movable with respect to the top plate body 1b. Therefore, even if the occlusion plate 连结 connected to the mixing tube 8 and the burner opening 9 are axially offset, the spacer 14 is moved according to its offset size, and the outer periphery of the occluding plate 11 can be surely sealed and followed. The top surface of the top plate body 1 of the periphery of the opening 9 of the burner is used. The fire frame 2 is composed of an annular fire frame 23 and five fire frame claw holes, and the fire frame claws 2b are fixedly supported by a predetermined interval in the circumferential direction of the frame 23. The fire frame 2a is fitted to the gap which has been formed on the outer peripheral portion of the occlusion plate n, and is placed on the occlusion plate U in a state of being positioned. Namely, the "fire frame 2" is configured to be placed on the mixing tube 8 through the blocking plate. Thereby, the axis of the burner body 4 assembled to the mixing pipe 8 can be aligned with the axis of the cradle 2. Furthermore, even if the furnace body 5 is strained, etc., the distance between the bottom plate body ίο and the bottom portion 6 is also changed. The fire frame 2 can also be burned by being placed on the occlusion plate 11 which has been connected to the mixing pipe 8. The distance between the body 4 and the bottom of the pot placed on the fire frame 2 is maintained constant. Further, although not shown, even if the frame of the flame frame is placed on the top plate body 1 , the inner circumferential surface of the annular frame frame can be fitted to the outer peripheral portion of the blocking plate 11 . The axis of the burner body is aligned with the axis of the fire frame. Further, for example, when the lower edge of each of the frame claws constitutes the frame on which the mounting surface is formed, the inner side surface of the lower portion of each of the frame claws may be fitted to the outer peripheral portion of the blocking plate 11. The burner body 4 has a mother burner portion 15 and a sub-burner portion 16 to constitute a so-called mother burner. As shown in Fig. 3, the mixing pipe 8 includes a mixed burner portion 17' for supplying the mixed gas to the mother burner portion 15 and a mixed burner portion 18' for supplying the mixed gas to the sub-combustor. The burner unit 16 is. As shown in Fig. 2, the downstream end portion 8a of the mixing tube 8 is housed in the mixing tube portion 18 for the sub-combustor in the inside of the mixing tube portion 17 for the mother burner to form a double tube structure. As shown in Figs. 1 and 2, the burner body 4 is constituted by a burner main body 19 and a pair of burner heads (a mother burner head 20 and a sub-burner head 21). The burner main body 19 is formed on the outer side thereof to form the distribution chamber 22 of the mother burner portion 15, and the distribution chamber 23 of the sub-burner portion 16 is formed inside. The plurality of mother burner flame holes 24' are formed on the outer circumference of the mother burner portion 丨5 by the distribution chamber 22 of the mother burner portion 15, and the distribution chamber 23 of the sub-burner portion 16 is formed. The set burner head 21 is placed, and the 201219723 number burner burner hole 25 is formed on the outer periphery of the sub-burner portion 16. Further, in the central portion of the lower portion of the combustion main body 19, a cylindrical mixed airflow portion 26 is provided corresponding to the downstream end portion 8a of the mixing pipe. As shown in Fig. 2, the mixed airflow entering portion 26 is constituted by the outer side bypass passage π and the inner sub-combustion closed passage 28, and if the mixed airflow portion is reduced to the downstream end portion Sa of the mixing tube 8, The mother burner passage η is in communication with the mother burner mixing pipe portion, and the sub-burner communication system is in communication with the sub-combustor mixing pipe portion 18. Further, the mixed airflow inlet portion % is fitted to the downstream end portion 8a of the mixing pipe 8, and is detachably attachable, and is configured to easily detach the burner body 4 from the mixing pipe 8 during maintenance such as cleaning. Further, as shown in Fig. 2, the mixed airflow entering portion 26 is disposed at a position below the sub-burner portion 16 of the combustor body 19. Therefore, as shown in Figs. 1 and 2, the mother burner passage 27 is controlled by the subroutine. The contact portion 29 that radially extends on the side of the burner portion 16 communicates with the distribution chamber 22 of the mother burner portion 15. Further, a gas nozzle (not shown) faces the upstream end of each of the mixing tube portion 17 for the mother burner and the mixing tube portion 18 for the sub-combustor of the mixing tube 8. When the fuel gas is ejected from the gas nozzle, the primary air is sucked as the fuel gas is ejected, and a mixed gas is generated. As shown in Fig. 2, an ignition target 30 is formed in a portion of the mother burner head 20. The ignition target 30 is opposed to the front end of the spark plug 32 of the mixing tube 8 through the support member 31, and receives the discharge of the ignition plug 32 to ignite the mother burner portion 15. The ignition plug 32 extends through the blocking plate 11 and upward. Further, in the first drawing, the thermocouple of the sub-combustor portion 16 is detected as indicated by reference numeral 33. Although not shown, the thermocouple 33 is also supported by the mixing tube 8 in the same manner as the ignition plug 32. 201219723, and extends upward through the blocking plate 11. As shown in the first and third figures, the flame formed by the mother burner portion 15 passes through the misalignment slit 20a which has been formed in the mother burner head 20, and is transferred to the sub-combustor portion 16, whereby The sub-burner portion 16 will ignite. The flame formed by the sub-combustion unit 16 supplies secondary air from the gap between the communication pipe portions 29. At this time, the occlusion plate 11 is formed to gradually increase the height from the outer periphery toward the downstream end portion 8a of the mixing tube 8 by the drop, thereby forming a secondary air flow rising from the upper surface of the top plate toward the burner body 4. . Therefore, not only the mother burner portion 15, but also a sufficient amount of secondary air can be supplied to the sub-combustor portion 16, and a good combustion state can be obtained. Further, in the present embodiment, the gas burner 1 is provided with the mother burner portion 15 and the sub-burner portion 16. However, although not shown, the mixing tube is fitted to the central portion of the burner body. The gas burner of the configuration can be suitably used in the present invention even in the case of a gas burner having a single burner portion. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial plan view showing a gas furnace of an embodiment of the present invention. Fig. 2 is a cross-sectional view showing the main part of the gas burner of the present embodiment. Fig. 3 is a perspective view showing a gas burner included in the gas burner of the embodiment. [Main component symbol description] 1.. Gas burner 2b... Fire holder claw 2.. Fire frame 3... Top plate 2a... Fire frame 4... Burner body 11 201219723 5. Furnace body 6 · _ · plate 7.. pedestal part 8.. mixing tube 8a... downstream end part 9.. burner opening 10.. top plate body 11... occlusion plate 12.. Inserting hole 13. Screw member 14·· Lining 14a.. Sealing part 14b...Flange part 14c...Folding lower part 15.. Mother burner part 16:.Burn burner Part 17. Mixing tube part for mother burner 18. Mixing tube part for sub-burner 19. Burner body 20.. Mother burner head 20a... Slit 21.. Sub burner head 22, 23... distribution chamber 24: female burner flame hole 25.. sub-burner flame hole 26.. mixed air flow inlet portion 27: female burner passage 28: sub-burner passage 29 .. .Contact pipe section 30.. Ignition dry 31.. Support member 32.. Ignition plug 33.. Thermocouple 12