200401615 玖、發明說明 【發明所屬之技術領域】 本發明係有關全罩式安全帽之口部開閉器之支撐構造 〇 【先前技術】 作爲以完全覆蓋使用者的頭部以及面部的形式的全罩 式安全帽，根據情況，有著由於安全帽內的熱氣不流通會 產生遮蔽的霧，或由於使用者自身的熱氣而感覺不愉快的 情況。 因此，如圖10以及圖11所示，在顎保護部101上設 置將外氣導入安全帽內更換熱氣的換氣孔100，行駛中從此 換氣孔100將外氣導入。 換氣孔100透過口部開閉器102根據需要開啓關閉， 通常，口部開閉器在開啓關閉時的轉動中，以單一的轉動 中心作爲中心可轉動地被支撐，在口部開閉器102的開閉 動作中的轉動軌跡描繪出一定的弧度進行開啓關閉。 但是，爲了迅速除去遮蔽的霧或熱氣的不流通，有必 要增加外氣的導入量，以提高安全帽內的換氣效率，作爲 其手段之一，可以考慮透過形成較大的換氣孔來增加外氣 的導入量。 【發明內容】 但是，由於口部開閉器的大小要與換氣孔的大小相對 應，若口部開閉器爲具有前述單一的轉動中心的支撐形式 ，則如圖10以及圖11所市，根據口部開閉器102的支撑 200401615 位置，在口部開閉器開啓狀態中，口部開閉器102從顎保 護部101表面向外側突出很多，有損害安全帽的設計的可 能性。 因此，可以舉出使口部開閉器在全開狀態中的角度減 小、減少突出量的例子，但是，即使加大換氣孔，也不能 增加外氣的導入量。 相反，也可以考慮使口部開閉器向安全帽的內側方向 開閉的方法，在此方法中，由於口部開閉器向安全帽的內 側較大的突出，也有必要在顎保護部的內側確保口部開閉 器的空間，從在開閉中的操作性這一點來看，現實上不可 能採用。 即，進行實現外氣的導入量的增加和使設計性及操作 性得到滿足的口部開閉器的轉動中心的設定是十分困難的 ，這是減少安全帽設計自由度的主要原因。 因此，本發明是以在增加外氣的導入量和滿足良好設 計性以及操作性的同時，謀求加大安全帽設計的自由度爲 技術問題，以提供解決這一技術問題的新型口部開閉器的 支撐構造爲目的。 本發明爲了達到上述目的，採用了下述的技術手段。 該技術手段是一種支撐構造，其將設置在全罩式安全 帽的顎保護部上的開閉換氣孔的口部開閉器，以相對於固 定在帽體側的口部開閉器支撐部可轉動自如之方式予以支 撐；其特徵在於：係具有複數個口部開閉器開閉用的轉動 中心，在從口部開閉器的關閉狀態向開啓狀態的開啓動作 200401615 途中，前述轉動中心進行切換。（申請專利範圍第1項） 作爲具體實施前述申請專利範圍第1項的構成，例如 ，如圖1至圖5A至5E所示，可以舉出其構成爲，在固定 於帽體側的口部開閉器支撐部、以及以相對於其可轉動的 方式被支撐的口部開閉器中，任一方係具備引導轉動的第1 導軸S1和第2導軸S2，另一方則具備與該2個導軸相對應 的由複數圓弧形構成的嵌合部；將第1導軸S1以可移動的 方式嵌合第1嵌合部U1和與其連接的第2嵌合部U2，在 第2導軸S2以可移動的方式嵌合第3嵌合部U3 ; 在口部開閉器開啓動作的初期，第1導軸S1被第1嵌 合部U1引導、第2導軸S2被第3嵌合部U3引導，而使口 部開閉器以兩嵌合部所具有的圓弧的共通中心點的第1中 心點P1爲轉動中心進行轉動；在開啓動作的途中，從第1 導軸S1到達第1嵌合部U1與第2嵌合部U2的連接點的時 點開始，轉動中心從第1中心點P1切換到第2嵌合部U2 所具有的圓弧的第2中心點P2，使口部開閉器以第2導軸 S2爲中心進行轉動。（申請專利範圍第2項） 根據本發明的支撐構造，在圖5A至5C的開啓動作中 ，第1中心點P1是口部開閉器1的轉動中心，在第1嵌合 部U1和第3嵌合部U3達到圖5C的狀態的同時，口部開 閉器1的轉動中心切換到第2中心點P2，呈圖5D至圖5E 的開啓動作，在如圖5E以及圖4所示的全開狀態中，可以 最小限度地抑制口部開閉器1從顎保護部A1的表面向外的 突出量。 200401615 前述所例示的方式是口部開閉器1的轉動中心爲兩個 位置的形式，本發明並不限於此，也包含了如例如含有曲 率不同的圓弧的嵌合部（圖6)、或將直線透過某一角度的彎 曲部連接構成的嵌合部（圖7)那樣的，透過在嵌合部的轉動 中途移動轉動中心，由超過兩個位置的轉動中心構成的形 式。 在圖示中，在口部開閉器1上設置各嵌合部，將各導 軸設置在開閉器支撐板2上，本發明也包含了與此相反形 式的支撐構造。 在申請專利範圍第2項中，各嵌合部若是各導軸嵌合 的形態，則可以是孔形狀或者槽形態中的任何一個。 另外，在申請專利範圍第2項的情況下，如圖8所示 ，將第1導軸S1以可移動的方式嵌合的第1嵌合部U1及 第2嵌合部U2、和將第2導軸S2以可移動的方式嵌合的 第3嵌合部U3，是形成槽形態；在該槽形態的第2嵌合部 U2和第3嵌合部U3間設置段差，藉此就算在兩嵌合部的 交叉部仍不致使各自的軸跑到其他的嵌合部。（申請專利範 圍第3項） 【實施方式】 以下參照圖說明本發明的實施例。 圖1表示全罩式安全帽A，如圖3及圖4所示，在顎 保護部A1上具有透過口部開閉器1開啓關閉的換氣孔A2 〇 本實施例的全罩式安全帽A爲周知的形態，具備：吸 200401615 收衝擊襯裏C、頭部的內裝墊子D、臉頰墊DL、DR和面罩 E而構成，該吸收衝擊襯裏C在以纖維強化樹脂材料所形 成的既定形狀的帽體B的內側’使用泡沬塑料或者與此相 同的具有吸收衝擊性能的材質構成’該頭部的內裝墊子D 由聚氨基甲酸乙酯材料等構成’可拆裝地配設在此吸收衝 擊襯裏C的內側，該臉頰墊DL、DR配設在與臉頰和下巴 相對應的兩側部，該面罩E使用透明或者有色透明且具有 彈性的合成樹脂板形成爲既定形狀。 口部開閉器1可轉動地支撐在安裝於顎保護部A1上的 口部開閉器支撐部2上，其表面在全閉狀態中，與口部開 閉器支撐部2的表面同面。 口部開閉器支撐部2具有透過口部開閉器1開閉的換 氣孔3，固定在開口於顎保護部A1的貫通口 A3上，其表 面與顎保護部A1的表面幾乎同面。 口部開閉器1的構成，基本上是在開閉器本體11的左 右分別設置的第1嵌合部U1和第2嵌合部U2上，透過分 別在口部開閉器支撐部2的左右設置的第1導軸S1和第2 導軸S2的嵌合，以可轉動的方式支撐在口部開閉器支撐板 2上。 具體如圖2至圖5A至5E所示，第1嵌合部U1和第2 嵌合部U2在開閉器本體11的左右一體形成的支撐板1L、 1R上開口，第1導軸S1和第2導軸S2，在換氣孔3向左 右突出於與前述支撐板1L、1R面對地一體形成的支撐板 3L，3R地形成，透過使第1導軸S1嵌合於第1嵌合部U1 200401615 、使第2導軸S2嵌合於第3嵌合部U3，口部開閉器1以 可轉動的方式被支撐在口部開閉器支撐板2上。 口部開閉器1透過在第1中心點P1和第2中心點P2 的兩個位置的轉動中心的轉動，進行開啓關閉動作，如圖 5A至5E所示，在從關閉狀態到開啓狀態的轉動途中，轉 動中心從第1中心點P1切換至第2中心點P2。 以下詳述轉動中心的切換構造，則如圖5A至5E所示 ，第1嵌合部U1和第3嵌合部U3在從口部開閉器1的關 閉狀態到開啓的動作中，初期以第1中心點P1爲轉動中心 ，描繪各自的半徑不同的圓弧Cl、C2，在口部開閉器1的 開啓動作的途中，轉動中心從第1中心點P1切換爲與第2 導軸S2同心的第2中心點P2，而且，在第2嵌合部U2切 換後的開啓動作中，形成以第2中心點P2爲轉動中心，描 繪圓弧C3的形狀。 第1嵌合部U1和第2嵌合部U2在從第1中心點P1切 換到第2中心點P2的位置上連接。 中心點切換的位置是在口部開閉器1的轉動途中，第1 嵌合部U1的彎曲部分U11與第1導軸S1接觸，以第1中 心點P1爲轉動中心的轉動完成的位置，此時是第3嵌合部 U3的終端部U31與第2導軸S2接觸的位置。（參照圖5C) 根據圖5A至5E說明基於這樣的支撐構造的口部開閉 器1的開閉動作。 首先，如圖5A所示，在口部開閉器1的全閉狀態中， 第1嵌合部U1的始端部U12與第1導軸S1接觸，第2導 200401615 軸S2位於第2嵌合部U2與第3嵌合部U3的交叉部位（第3 嵌合部U3的始端部U32)。 接著，若使口部開閉器1從全閉狀態到開啓動作，則 如圖5B所示，口部開閉器1以第丨中心點pi爲轉動中心 ，第1嵌合部U1和第3嵌合部U3被第1導軸S1和第2導 軸S2引導而轉動。 於是，若口部開閉器1轉動，則在圖5C所示的位置， 由於第1嵌合部U1的彎曲部分U11與第1導軸S1接觸， 第3嵌合部U3的終端部U31與第2導軸S2接觸，轉動中 心從第1中心點P1切換到第2中心點P2。 若使口部開閉器1從此位置開始開啓動作，則如圖5D 所示，口部開閉器1以第2中心點P2爲轉動中心，第2嵌 合部U2被第1導軸S1引導而轉動。 於是，在全開狀態中，如圖5E所示，第2嵌合部U2 的終端部U21與第1導軸S1接觸，口部開閉器1的轉動停 止。 根據本實施例的支撐構造，在全開狀態中，口部開閉 器1的前端部並非那樣從口部開閉器支撐部2的表面向外 突出，而且，可以使換氣孔3全開。 圖6及圖7分別表示在口部開閉器1中的轉動中心超 過兩個位置的例子。 另外，在圖6中的各嵌合部爲第1嵌合部U10、第2 嵌合部U20、第3嵌合部U30，圖7中的各嵌合部爲第1嵌 合部U10’ 、第2嵌合部U20’ 、第3嵌合部U30’ 。 11 200401615 在圖6中的第1嵌合部U10以及第3嵌合部U30的形 式是在嵌合部中的圓弧的曲率從中途部分發生變化的形式 ，具有沿此不同曲率的圓弧轉動的各個轉動中心點。 具體的是，與從始端部到轉動中途的圓弧C4相比，從 該轉動中途到終端部的圓弧C5的半徑更大，因此，作爲圓 弧C4的轉動中心的第1中心點P3的位置與作爲圓弧C5的 轉動中心的第2中心點P4呈不同的位置。 即，在圓弧C4中的轉動中心是第1中心點P3，從此 轉動中途開始連續，切換至沿圓弧C5的轉動時，其轉動中 心從第1中心點P3到第2中心點P4之間逐漸移動，切換 至該第2中心點P4。 這種情況下，轉動中心即使在從第1中心點P3向第2 中心點P4移動的狀態下，因爲存在沿圓弧C5的轉動，所 以在從第1中心點P3到第2中心點P4之間，也存在多個 中心點。 於是，在完成沿以第2中心點P4爲轉動中心的圓弧 C5的轉動的同時，開始了沿以第3中心點P5爲轉動中心 的圓弧C6的轉動。 因此，在前述實施例中的口部開閉器的轉動中心數是 第1、第2、第3中心點的3個位置，在從第1中心點P3 到第2中心點P4之間存在的多個中心點，即使是在存在這 樣的3個位置以上的多個轉動中心的構成中，也是可以實 施的。 在圖7中的第1嵌合部U10’ 、第2嵌合部U20’ 、第 200401615 3嵌合部U30’的形式是透過各種形狀的曲部將多個直線 ST1〜ST9連接而構成的形式。 此構成是在口部開閉器的轉動運動中，各導軸每次與 曲部接觸時，對轉動運動加以限制，透過這種限制，可以 在口部開閉器的開啓操作中發揮棘輪功能。 另外，在此構成中，因爲口部開閉器是沿各直線移動 ，嚴格地講不是轉動運動，在觀察口部開閉器整體的動作 時，進行與轉動運動相近的動作。 即，由於成爲一邊想沿各直線移動、一邊想要轉動的 動作，在其動作中產生位移，大體可以看作是以轉動的中 心點P6以及中心點P7爲轉動中心的動作。 因此，本實施例的形式也是存在超過兩個位置的多個 轉動的中心點的形式。 對在前述實施例中第1嵌合部U1和第2嵌合部U2作 爲貫通孔的情況進行了說明，在本發明中，也可以任意做 成如圖8所示的槽形態。 下面，說明作爲本實施例的槽形態的第1嵌合部和第2 嵌合部的形式。分別對本實施例的第1嵌合部賦予符號仍 ’對第2嵌合部賦予符號U2’ ，對第3嵌合部賦予符號 U3，。 另外，分別賦予第1導軸爲符號S1’ ，第2導軸爲符 號 S2，。 基本的外形，第1嵌合部U1，、第2嵌合部U2，以 及第3嵌合部U3’均與前述的第1嵌合部U1、第2嵌合部 200401615 U2及第3嵌合部U3相同。 第3嵌合部U3’的底面U3的高度位置位於從第1嵌 合部U1’和第2嵌合部U2’的底部U4開始降低一層的位 置，據此，在第3嵌合部U3’的周圍形成壁面狀的段差w 〇 第1導軸S1’爲與第1嵌合部ur的底部U4接近的 長度，第2導軸S2’爲與第3嵌合部U3’的底部U3接近 的長度，第2導軸S2’保持前述段差W，確實地保持向第 3嵌合部U 3 ’內的嵌合狀態。 根據本實施例，與前述的實施例相同，在全開狀態中 ，口部開閉器1的前端部並非那樣從口部開閉器支撐部2 的表面向外突出，而且，可以在使換氣孔3全開的基礎上 ，第2導軸S2 透過段差W，更加確實地保持在第3嵌合 部U3’上。 圖9是表示口部開閉器1的其他實施例。 本實施例的口部開閉器1在開閉器本體11的後側， 具有用於對從換氣孔向安全帽內流入的行駛風進行整流的 整流板12。 本實施例的第1嵌合部U1和第2嵌合部U2爲如圈8 所示的槽形態。 整流板12是由橫跨一體形成在口部開閉器本體11左 右的支撐板1L、1R而固定安裝的第1整流板12A ’和擒跨 該第1整流板和口部開閉器本體中央而豎設的第2整流板 12B構成的。 200401615 第1整流板12A將換氣孔以大致中央部分爲界分成上 下，第2整流板12B將換氣孔的下側以大致中央部分爲界 分成左右。 根據這樣的口部開閉器1，從換氣孔流入安全帽內的行 駛風透過整流板12，可以不使行駛風分散，而集中地流入 安全帽內。 本發明如以上所說明的那樣，在口部開閉器的全開狀 態中，口部開閉器的前端部並不太從口部開閉器支撐部的 表面向外突出，而且，可以使換氣孔全開。 因此，在增加外氣的導入量和滿足良好的設計性以及 操作性的同時，可以實現增加安全帽設計的自由度。 再有，根據申請專利範圍第2項的發明，可以具體提 供具有前述效果的支撐構造。 另外，根據申請專利範圍第3項的發明，在前述效果 的基礎上，由於透過段差第2導軸更加確實地保持在第3 嵌合部上，在口部開閉器的開啓動作中，第2導軸不會脫 離第3嵌合部，可以對口部開閉器確實地進行轉動導向， 還具有非常良好的效果。 【圖式簡單說明】 (一）圖式部分 圖1是實施本發明的口部開閉器的支撐構造的全罩式 安全帽的剖面圖。 圖2是表示口部開閉器的支撐構造的分解立體圖。 圖3是主要部放大圖。 15 200401615 圖4是表示開啓狀態的主要部放大圖。 圖5A至5E是表示開啓關閉動作的行程圖。 圖6是表示各嵌合部的其他實施例。 圖7是表不各嵌合部的其他實施例。 圖8是表示第1嵌合部和第2嵌合部的其他實施例的 立體圖。 圖9是表示口部開閉器的支撐構造的其他例的分解立 體圖。 圖10是表币習知支撑構造的剖面圖。 圖11是表示習知支撐構造的剖面圖。 (二）元件代表符號 A 全罩式安全帽 1 口部開閉器 S1， SI， 第1導軸 S2， S2， 第2導軸 m， Ul，， U10 第1嵌合部 U2， U2,， U20 第2嵌合部 U3， U3,， U30 第3嵌合部 PI 第1中心點 P2 第2中心點 W 段差 16200401615 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a support structure for a mouth shutter of a full-face helmet. [Prior art] As a full-face cover that completely covers a user's head and face Depending on the situation, there may be a case where the masked mist is generated due to the non-circulation of heat in the helmet, or the user may feel uncomfortable due to the user's own heat. Therefore, as shown in FIG. 10 and FIG. 11, the jaw guard 101 is provided with a vent hole 100 for introducing outside air into the helmet to exchange hot air, and the vent hole 100 is used to introduce outside air during driving. The vent hole 100 is opened and closed through the mouth shutter 102 as required. Generally, the mouth shutter is rotatably supported with a single rotation center as a center during the rotation of the mouth shutter, and the mouth shutter 102 is opened and closed. The turning trajectory in action draws a certain arc to open and close. However, in order to quickly remove the shielding fog or the non-circulation of hot air, it is necessary to increase the amount of outside air introduced to improve the ventilation efficiency in the helmet. As one of the means, it is considered to form a larger ventilation hole. Increase the amount of outside air introduced. [Summary of the Invention] However, since the size of the mouth shutter should correspond to the size of the ventilation hole, if the mouth shutter is a support form having the aforementioned single rotation center, as shown in Fig. 10 and Fig. 11, according to Position 200401615 of the mouth shutter 102. When the mouth shutter is opened, the mouth shutter 102 protrudes a lot from the surface of the jaw protection portion 101, which may damage the design of the helmet. Therefore, an example of reducing the angle of the mouth shutter in the fully opened state and reducing the amount of protrusion can be cited. However, even if the vent hole is enlarged, the amount of outside air introduced cannot be increased. Conversely, a method of opening and closing the mouth shutter toward the inside of the helmet may also be considered. In this method, since the mouth shutter protrudes to the inside of the helmet, it is also necessary to secure the mouth on the inside of the jaw guard. From the viewpoint of operability during opening and closing, it is impossible to adopt the space of the shutter. That is, it is very difficult to set the center of rotation of the mouth shutter to achieve an increase in the amount of introduction of outside air and satisfy design and operability. This is the main reason for reducing the degree of freedom in the design of the helmet. Therefore, the present invention aims to provide a new type of mouth shutter that solves this technical problem while increasing the amount of outside air introduction and satisfying good design and operability while seeking to increase the degree of freedom in the design of the helmet. Support structure for the purpose. In order to achieve the above object, the present invention adopts the following technical means. This technical means is a support structure that rotates an opening-and-closing shutter of an opening / closing vent hole provided on a jaw protecting portion of a full-face helmet, so as to be rotatable with respect to the opening-and-closing shutter supporting portion fixed to the cap body It is supported in a free manner; it is characterized in that it has a plurality of rotation centers for opening and closing the mouth shutter. During the opening action 200401615 from the closed state of the mouth shutter to the opened state, the aforementioned rotation center is switched. (Item 1 of the scope of patent application) As a specific implementation of the above item 1 of the scope of patent application, for example, as shown in FIGS. 1 to 5A to 5E, the structure can be exemplified by the mouth portion fixed to the cap body side. One of the shutter support portion and the mouth shutter supported rotatably is provided with a first guide shaft S1 and a second guide shaft S2 for guiding rotation, and the other is provided with the two guide shafts. A fitting portion composed of a plurality of circular arcs corresponding to the guide shaft; the first guide shaft S1 is movably fitted into the first fitting portion U1 and the second fitting portion U2 connected thereto, and the second guide portion S1 is The shaft S2 is movably fitted to the third fitting portion U3; at the initial stage of the opening operation of the mouth shutter, the first guide shaft S1 is guided by the first fitting portion U1, and the second guide shaft S2 is fitted by the third The U3 is guided, and the mouth shutter is rotated with the first center point P1, which is the common center point of the arc of the two fitting portions, as the rotation center. During the opening operation, the first guide shaft S1 reaches the first Starting at the point of connection between the first fitting portion U1 and the second fitting portion U2, the rotation center is switched from the first center point P1 to the second fitting portion U2. The second center point P2 of the arc has the mouth shutter rotating around the second guide shaft S2. (Item 2 of the scope of patent application) According to the support structure of the present invention, in the opening operation of FIGS. 5A to 5C, the first center point P1 is the rotation center of the mouth shutter 1, and at the first fitting portion U1 and the third When the fitting portion U3 reaches the state shown in FIG. 5C, the rotation center of the mouth shutter 1 is switched to the second center point P2, and the opening action is shown in FIGS. 5D to 5E. In the fully opened state shown in FIGS. 5E and 4 In this way, the amount of protrusion of the mouth shutter 1 from the surface of the jaw guard A1 can be minimized. 200401615 The method exemplified above is a form in which the center of rotation of the mouth shutter 1 is two positions. The present invention is not limited to this, but also includes, for example, a fitting portion including arcs with different curvatures (FIG. 6), or A fitting portion (FIG. 7) that is formed by connecting a straight line through a bent portion at a certain angle, is formed by moving the rotation center halfway through the rotation of the fitting portion, and the rotation center is formed by more than two positions. In the figure, each fitting portion is provided on the mouth shutter 1 and each guide shaft is provided on the shutter support plate 2. The present invention also includes a support structure of the opposite type. In item 2 of the scope of patent application, if the respective fitting portions are in the form of the respective guide shafts being fitted, they may be in either a hole shape or a groove shape. In addition, in the case of applying for the second item of the patent scope, as shown in FIG. 8, the first fitting portion U1 and the second fitting portion U2 and the first fitting portion U1 and the second fitting portion U2 that movably fit the first guide shaft S1 are shown in FIG. 8. The third fitting portion U3 in which the two guide shafts S2 are movably fitted is formed in a groove shape; a step is provided between the second fitting portion U2 and the third fitting portion U3 in the groove shape. The intersection of the two fitting portions still does not cause the respective shafts to run to the other fitting portions. (Item 3 of Patent Application Range) [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows a full-face helmet A, as shown in Figs. 3 and 4, a jaw protection portion A1 has a vent hole A2 that is opened and closed through a mouth shutter 1. The full-face helmet A of this embodiment It is a well-known form, and it is provided with a suction lining 200401615, an impact lining C, a head inner cushion D, a cheek pad DL, DR, and a mask E. The impact absorbing lining C is formed in a predetermined shape formed of a fiber-reinforced resin material. The inside of the cap body B is made of foamed plastic or the same material with shock absorption performance. The head's built-in cushion D is made of polyurethane material and the like. On the inner side of the impact liner C, the cheek pads DL and DR are arranged on both sides corresponding to the cheek and the chin, and the mask E is formed into a predetermined shape using a transparent or colored transparent and elastic synthetic resin plate. The mouth shutter 1 is rotatably supported on the mouth shutter supporting portion 2 mounted on the jaw protection portion A1, and its surface is in the same state as the surface of the mouth shutter supporting portion 2 in the fully closed state. The mouth shutter support portion 2 has a ventilation hole 3 opened and closed through the mouth shutter 1, and is fixed to the through-hole A3 opened to the jaw protection portion A1, and its surface is almost the same as the surface of the jaw protection portion A1. The configuration of the mouth shutter 1 is basically provided on the left and right of the first and second fitting portions U1 and U2 provided on the left and right sides of the shutter body 11, respectively. The fitting of the first guide shaft S1 and the second guide shaft S2 is rotatably supported on the mouth shutter support plate 2. Specifically, as shown in FIGS. 2 to 5A to 5E, the first fitting portion U1 and the second fitting portion U2 are opened on the support plates 1L and 1R integrally formed on the left and right of the shutter body 11, and the first guide shaft S1 and the first 2 guide shafts S2 are formed in the ventilation holes 3 to the left and right on the support plates 3L and 3R integrally formed facing the support plates 1L and 1R, and the first guide shaft S1 is fitted to the first fitting portion U1 200401615 The second guide shaft S2 is fitted to the third fitting portion U3, and the mouth shutter 1 is rotatably supported on the mouth shutter support plate 2. The opening and closing device 1 performs opening and closing operations by rotating the centers of rotation at two positions of the first center point P1 and the second center point P2, as shown in FIGS. 5A to 5E. On the way, the rotation center is switched from the first center point P1 to the second center point P2. The switching structure of the rotation center is described in detail below. As shown in FIGS. 5A to 5E, the first fitting portion U1 and the third fitting portion U3 are moved from the closed state of the mouth shutter 1 to the opened state, and the initial movement 1 center point P1 is the rotation center, and the arcs Cl and C2 with different radii are drawn. During the opening operation of the mouth shutter 1, the rotation center is switched from the first center point P1 to the center concentric with the second guide axis S2. At the second center point P2, in the opening operation after the second fitting portion U2 is switched, the shape of the arc C3 is drawn with the second center point P2 as the rotation center. The first fitting portion U1 and the second fitting portion U2 are connected at a position switched from the first center point P1 to the second center point P2. The position at which the center point is switched is the position where the bending portion U11 of the first fitting portion U1 is in contact with the first guide shaft S1 during the rotation of the mouth shutter 1, and the rotation is completed with the first center point P1 as the rotation center. The time is the position where the terminal portion U31 of the third fitting portion U3 is in contact with the second guide shaft S2. (Refer to FIG. 5C) The opening and closing operation of the mouth shutter 1 based on such a support structure will be described with reference to FIGS. 5A to 5E. First, as shown in FIG. 5A, in the fully closed state of the mouth shutter 1, the starting end portion U12 of the first fitting portion U1 is in contact with the first guide shaft S1, and the second guide 200401615 is located at the second fitting portion The intersection of U2 and the third fitting portion U3 (the start end portion U32 of the third fitting portion U3). Next, if the mouth shutter 1 is moved from the fully closed state to the opening operation, as shown in FIG. 5B, the mouth shutter 1 is centered on the first center point pi as the rotation center, and the first fitting portion U1 and the third fitting portion are fitted. The portion U3 is guided and rotated by the first guide shaft S1 and the second guide shaft S2. Then, if the mouth shutter 1 is rotated, at the position shown in FIG. 5C, since the curved portion U11 of the first fitting portion U1 contacts the first guide shaft S1, the terminal portion U31 of the third fitting portion U3 and the first When the two guide shafts S2 come into contact, the rotation center is switched from the first center point P1 to the second center point P2. When the mouth shutter 1 is opened from this position, as shown in FIG. 5D, the mouth shutter 1 is centered on the second center point P2, and the second fitting portion U2 is guided by the first guide shaft S1 to rotate. . Then, in the fully opened state, as shown in FIG. 5E, the terminal portion U21 of the second fitting portion U2 comes into contact with the first guide shaft S1, and the rotation of the mouth shutter 1 is stopped. According to the support structure of the present embodiment, in the fully opened state, the front end portion of the mouth shutter 1 does not protrude outward from the surface of the mouth shutter support portion 2, and the vent hole 3 can be fully opened. Figs. 6 and 7 show examples in which the center of rotation in the mouth shutter 1 exceeds two positions, respectively. In addition, each fitting portion in FIG. 6 is a first fitting portion U10, a second fitting portion U20, and a third fitting portion U30, and each fitting portion in FIG. 7 is a first fitting portion U10 ', The second fitting portion U20 'and the third fitting portion U30'. 11 200401615 The form of the first fitting portion U10 and the third fitting portion U30 in FIG. 6 is a form in which the curvature of the arc in the fitting portion is changed from a halfway portion, and the arc has a rotation along this different curvature The center point of each rotation. Specifically, the radius of the arc C5 from the middle of the rotation to the end is larger than that of the arc C4 from the beginning to the middle of the rotation. Therefore, the first center point P3 of the center of rotation of the arc C4 is The position is different from the second center point P4 which is the rotation center of the arc C5. That is, the rotation center in the arc C4 is the first center point P3, and the rotation is continued from the middle of the rotation. When switching to the rotation along the arc C5, the rotation center is from the first center point P3 to the second center point P4. Move gradually and switch to this second center point P4. In this case, even if the rotation center is moving from the first center point P3 to the second center point P4, since there is a rotation along the arc C5, the rotation center is between the first center point P3 and the second center point P4. There are also multiple central points. Then, the rotation along the arc C5 with the second center point P4 as the rotation center is completed, and the rotation along the arc C6 with the third center point P5 as the rotation center is started. Therefore, in the foregoing embodiment, the number of rotation centers of the mouth shutter is three positions of the first, second, and third center points, and there are many between the first center point P3 and the second center point P4. The center points can be implemented even in a configuration in which there are a plurality of rotation centers having three or more such positions. The form of the first fitting portion U10 ′, the second fitting portion U20 ′, and the 200401615 3 fitting portion U30 ′ in FIG. 7 is a form in which a plurality of straight lines ST1 to ST9 are connected through curved portions of various shapes. . This configuration restricts the rotation movement of each guide shaft each time the guide shaft contacts the curved portion during the rotation movement of the mouth shutter. Through this restriction, the ratchet function can be exerted in the opening operation of the mouth shutter. In addition, in this configuration, since the mouth shutter is moved along each straight line, strictly speaking, it is not a rotational movement, and when the overall movement of the mouth shutter is observed, an action similar to the rotation movement is performed. In other words, since it is an operation that wants to move along each straight line and rotates, the displacement occurs during the operation. Generally, it can be regarded as the operation with the center point P6 and P7 of the center of rotation as the center of rotation. Therefore, the form of this embodiment is also a form in which there are a plurality of center points of rotation in more than two positions. In the foregoing embodiment, the case where the first fitting portion U1 and the second fitting portion U2 are used as through holes has been described. In the present invention, a groove shape as shown in FIG. 8 may be arbitrarily formed. The form of the first fitting portion and the second fitting portion as the groove shape of the present embodiment will be described below. The symbols are assigned to the first fitting portion of the present embodiment, and the symbol U2 is given to the second fitting portion, and the symbol U3 is given to the third fitting portion. The first guide axis is given the symbol S1 'and the second guide axis is given the symbol S2. The basic shape, the first fitting portion U1, the second fitting portion U2, and the third fitting portion U3 'are all fitted to the aforementioned first fitting portion U1, second fitting portion 200401615 U2, and third fitting The part U3 is the same. The height position of the bottom surface U3 of the third fitting portion U3 'is located at a position lowered one level from the bottom U4 of the first fitting portion U1' and the second fitting portion U2 ', and accordingly, at the third fitting portion U3' A wall surface-shaped step w surrounds the first guide shaft S1 ′ is a length close to the bottom U4 of the first fitting portion ur, and the second guide shaft S2 ′ is close to the bottom U3 of the third fitting portion U3 ′. In the length, the second guide shaft S2 'maintains the aforementioned step W, and reliably maintains the fitted state into the third fitting portion U3'. According to this embodiment, as in the previous embodiment, the front end portion of the mouth shutter 1 does not protrude outward from the surface of the mouth shutter support portion 2 in the fully opened state, and the vent hole 3 can be made On the basis of full opening, the second guide shaft S2 penetrates the step W and is more surely held on the third fitting portion U3 '. FIG. 9 shows another embodiment of the mouth shutter 1. The mouth shutter 1 of this embodiment is provided with a rectifying plate 12 on the rear side of the shutter body 11 for rectifying the traveling wind flowing from the ventilation hole into the helmet. The first fitting portion U1 and the second fitting portion U2 in this embodiment have a groove shape as shown in a circle 8. The fairing plate 12 is a first fairing plate 12A ′ fixedly mounted across support plates 1L and 1R integrally formed on the left and right of the mouth shutter body 11, and is vertically erected across the center of the first fairing plate and the mouth shutter body. The second rectifying plate 12B is provided. 200401615 The first rectifying plate 12A divides the vent hole up and down with a substantially central portion as a boundary, and the second rectifying plate 12B divides the lower side of the vent hole with a roughly central portion as a boundary. According to such an opening / closing shutter 1, the traveling wind flowing into the helmet from the ventilation hole passes through the rectifying plate 12, so that the traveling wind can be concentrated into the helmet without dispersing the traveling wind. As described above, in the fully opened state of the mouth shutter, the front end portion of the mouth shutter does not protrude outward from the surface of the mouth shutter support portion, and the vent hole can be fully opened. . Therefore, it is possible to increase the degree of freedom in the design of the helmet while increasing the amount of outside air introduced and satisfying good design and operability. Furthermore, according to the invention in the second scope of the patent application, a support structure having the aforementioned effects can be specifically provided. In addition, according to the invention of claim 3 in the scope of the patent application, in addition to the aforementioned effects, the second guide shaft is more surely held on the third fitting portion due to the transmission step. In the opening operation of the mouth shutter, the second The guide shaft is not separated from the third fitting portion, and the mouth shutter can be surely rotated and guided, and has a very good effect. [Brief description of the drawings] (I) Schematic part Fig. 1 is a cross-sectional view of a full-face helmet with a supporting structure for implementing an opening and closing device of the present invention. Fig. 2 is an exploded perspective view showing a supporting structure of the mouth shutter. FIG. 3 is an enlarged view of a main part. 15 200401615 Fig. 4 is an enlarged view of a main part showing an opened state. 5A to 5E are stroke diagrams showing opening and closing operations. FIG. 6 shows another embodiment of each fitting portion. FIG. 7 shows another embodiment of each fitting portion. Fig. 8 is a perspective view showing another embodiment of the first fitting portion and the second fitting portion. Fig. 9 is an exploded perspective view showing another example of the support structure of the mouth shutter. Fig. 10 is a sectional view of a conventional support structure for a watch. Fig. 11 is a sectional view showing a conventional support structure. (II) Symbols for components A Full-face helmet 1 Mouth shutter S1, SI, 1st guide shaft S2, S2, 2nd guide shaft m, Ul ,, U10 1st fitting part U2, U2 ,, U20 2nd fitting part U3, U3 ,, U30 3rd fitting part PI 1st center point P2 2nd center point W segment 16