201249699 六、發明說明： 【發明所屬之技術領域】 本發明是有關於-種鼓式煞車機構，特 種可增進煞車制動效果之鼓式煞車機構。疋有關於 【先前技術】 請參閱第1圖及第2圖，一種習知 主要包括有-輪鼓1 〇、-固定盤2 〇、一煞Y 1車機構1 車導線40。 滹3〇及一煞 輪鼓10可以是連接於一車輪 框之-部份。 ^(未«示）或為輪 固定盤20是套設於輪鼓1〇之中，並且固 一盤體21、一煞車凸輪22、一固定銷23、盤2〇 ”有 片24、一第二煞車蹄片25及兩拉伸彈醫= 示’盤體21具有一直孔2la。煞車 第2圖所 部22a及一亩；h：舻？古4 、' /、有一抵接頭 2a及直柱體22b。直柱體迅是連接於抵接 並且直柱體22b是以轉動之方式穿設於盤體21之直^孔 之中。固定銷23是連接於盤體2卜第—煞車蹄片％是相 對於第二煞車蹄片25。在此，如第i圖所示，第―煞車蹄 片24之兩端是分別抵接於煞車凸輪22之抵接頭部22a及 固定銷23，以及第二煞車蹄片25之兩端亦是分別抵接於 煞車凸輪22之抵接頭部22a及固定銷23。如上所述，第 煞車蹄片24及第一煞車蹄片25可以固定銷23為旋轉支 點來進行旋轉，因而可根據操作需要來抵接摩擦輪鼓1〇， 進而可達成對輪鼓10 (或車輪）的煞車制動效果。此外，兩 4 201249699 拉伸彈簧26是連接於第一煞車蹄片24與第二煞車蹄片25 之間，其可使得苐一煞車蹄片24及第二煞車蹄片25之兩 立而分別保持抵接於煞車凸輪22之抵接頭部22a及固定銷 23。 煞車臂30是連接於煞車凸輪22之直柱體22b。 煞車導線40是連接於煞車臂3 0。 當煞車導線40拉動煞車臂30而驅使煞車凸輪22之直 柱體22b作動時，直柱體22b會旋轉一角度。此時，煞車 凸輪22之抵接頭部22a亦會隨之旋轉該角度而以轉動之方 式抵推第一煞車蹄片24及第二煞車蹄片25,因而迫使第 —煞車蹄片24及第二煞車蹄片25以固定銷23為支點轉動 而撐開以摩擦輪鼓10，進而可達成對輪鼓1 〇 (或車輪）的煞 車制動效果。 然而，當第一煞車蹄片24及第二煞車蹄片25被煞車 凸輪22之抵接頭部22a抵推撐開時，第一敏 比第二煞車蹄p優先完整接觸到輪“：^,2^ 整個煞車Λ輪22只能在固定盤2〇(或盤體 運動，而無法進行位移運動，故第二煞轉片=== 整與輪鼓10進行接觸摩擦。換句話說，第二煞車蹄片乃 與輪鼓1G之間的摩擦面積會不足，因而會使得煞車制動效 果不佳。 有鑑於此’本發明之目較要提供1鼓式敏 構，其可讓第-煞車蹄片及第二煞車蹄片皆完整摩捧幹 鼓，以提升整體煞車制動效果。 τ网 【發明内容】 201249699 本發明基本上採用如下所詳述之特徵以為了要解決上 述之問題。 本發明之一實施例提供一種鼓式煞車機構，包括：一 輪鼓；一固定盤，套設於該輪鼓之中，並且具有一盤體、 一煞車凸輪、一固定銷、一第一煞車蹄片及一第二煞車蹄 片，其中，該盤體具有一錐形孔，該煞車凸輪具有一抵接 頭部及一直枉體，該直柱體係連接於該抵接頭部，並且係 以轉動及偏擺之方式穿設於該盤體之該錐形孔之中，該固 定銷係連接於該盤體，該第一煞車蹄片係相對於該第二煞 車蹄片，該第一煞車蹄片之兩端係分別抵接於該煞車凸輪 之該抵接頭部及該固定銷，以及該第二煞車蹄片之兩端係 分別抵接於該煞車凸輪之該抵接頭部及該固定銷；一煞車 臂’連接於該煞車凸輪之該直柱體；以及—煞車導線，連 接於該煞車臂，其中，當該煞車導線拉動該煞車臂而驅使 _車凸輪之該直㈣作動時’該煞車凸輪之該抵接頭部 糸以轉動及偏擺之方式抵推該第—煞車蹄片及該第二煞 蹄片，以迫使該第一煞車蹄片及二 φ门久成乐一煞旱蹄片以該固定 鈉為支點轉動而抵緊摩擦該輪鼓。 根據上述實施例’該固定盤更具有—油封，以及該油 ^糸設置於該錐形孔之—内壁與_車凸輪之該直柱體之 /、，該盤體具有一直孔，該煞、車凸輪具有一 ^發明之另—實施例提供—種鼓·車機構，包括： 二!二二固定盤，套設於該輪鼓之中，並且具有-盤體、 ’、、”、—固定鎖、—第-煞車蹄片及-第二煞車蹄 抵接頭 6 201249699 =及錐她M，雜縣體L纟 係以轉動及偏擺之方式穿設於該盤體之該直：之；並且 車蹄片=:!，該第一煞車蹄片係相對於該第二煞 之該抵接頭部及該固定銷，以 :凸輪 :別:::該煞車凸輪之該抵接頭部㈣ 二連接於該煞車凸輪之該錐形柱體；以及一綠'車 使該:’其中’ #該煞車導線拉動該煞車臂而驅 =係以轉動及偏擺之方式抵推該第接 固定銷為支點轉動而抵緊摩擦該輪鼓。…、車蹄… 根據上述實施例，該固定盤更具有一油封， =係設置於該直孔之-内壁與該煞車凸輪之該錐形柱體乂之 又在本發明之中，該固定盤更具有至少-拉伸彈笼， 拉伸彈簧係連接於該第一煞車蹄片與該第二煞:蹄 為使本發明之上述目的、特徵和優點能更明顯易懂， 文特舉較佳實補魏合所關歧詳 、 【實施方式】 茲配合圖式說明本發明之較佳實施例。 第一實施例 請參閱第3A圖及第3B圖’本實施例之鼓式煞車機構 201249699 100主要包括有一輪鼓11〇、一固定盤12〇、_煞車臂13〇 及一煞車導線140。 輪鼓110可以是連接於—車輪之—輪框（未顯示）或為 輪框之一部份。 如第4圖所示，固定盤12〇是套設於輪鼓ιι〇之中， 並且固定盤120具有—盤體121、一煞車凸輪I〕】、一固定 銷123、一第一煞車蹄片124、一第二煞車蹄片125、兩拉 伸彈簧126及一油封127。 在本實施例之中，盤體121具有一錐形孔121a。 煞車凸輪122具有一抵接頭部122a及一直柱體122b 直柱體122b是連接於抵接頭部122a，並且直柱體12沘是 以轉動及偏擺之方式穿設於盤體121之錐形孔之中。 更具體而言，由於直柱體122b與錐形孔12u之間存在有 =間隙G，故穿設於錐形孔121a中之直杈體12沘可以進 行偏擺移動。此外，油封丨27乃是設置於錐形孔12U之一 内壁121a’與煞車凸輪122之直柱體12孔之間，其可在常 態下使直柱體122b定位於錐形孔12la之中央處f 固定銷123是連接於盤體12ι。 第一煞車蹄片124是相對於第二煞車蹄片IK。在此， 如第3A圖及第3B圖所示，第一煞車蹄片124之兩端是分 別抵接於煞車凸輪122之抵接頭部咖及固定銷123,以 蹄片125之兩端亦是分別抵接於煞車凸輪122 ==a及固定銷123。如上所述’第-煞車蹄片 Π4及第—煞車蹄片125可以固定銷123為旋轉支 行旋轉’因而可根據操作需要來抵接摩擦輪鼓”， 8 201249699 可達成對輪鼓110 (或車輪）的煞車制動效果。此外，兩拉 伸彈簧126是連接於第一煞車蹄片124與第二煞車蹄片125 之間，其可使得第一煞車蹄片124及第二煞車蹄片125之 兩端分別保持抵接於煞車凸輪122之抵接頭部122a及固定 銷 123。 煞車臂130是連接於煞車凸輪122之直柱體122b。 煞車導線140是連接於煞車臂130。 當煞車導線140拉動煞車臂130而驅使煞車凸輪122 之直柱體122b作動時，直柱體122b會先旋轉一角度。此 時，煞車凸輪122之抵接頭部122a亦會隨之旋轉該角度而 以轉動之方式抵推第一煞車蹄片124及第二煞車蹄片 125,因而迫使第一煞車蹄片124及第二煞車蹄片125以固 定銷123為支點轉動而撐開以摩擦輪鼓110。在此，第一 煞車蹄片124會比第二煞車蹄片125優先完全抵緊摩擦輪 鼓110。接著，由於由於直柱體122b與錐形孔121a之間 存在有間隙G，故穿設於錐形孔121a中之直柱體122b會 進行偏擺移動，因而可以迫使第二煞車蹄片125更進一步 以固定銷123為支點轉動而完全抵緊摩擦輪鼓110，如第 3B圖所示。此外，當直柱體122b在錐形孔121 a之中進行 偏擺移動時，設置於錐形孔121a之内壁121a’與煞車凸輪 122之直柱體122b間的油封127會受到壓迫而發生暫時的 彈性變形。 第二實施例 在本實施例中，與第一實施例相同之元件均標示以相 同之符號。 9 201249699 仍如第3A圖及第3B圖所示，本實施例之鼓式煞車機 構100’亦主要包括有一輪鼓110、一固定盤120’、一煞車 臂130及一煞車導線140。 如第5圖所示，固定盤120’是套設於輪鼓110之中， 並且固定盤120’具有一盤體121’、一煞車凸輪122’、一固 定銷123、一第一煞車蹄片124、一第二煞車蹄片125、兩 拉伸彈簧126及一油封127。 在本實施例之中，盤體12Γ具有一直孔121’a。 煞車凸輪122’具有一抵接頭部122a及一錐形柱體 122’b。錐形柱體122’b是連接於抵接頭部122a，並且錐形 柱體122’b以轉動及偏擺之方式穿設於盤體12Γ之直孔 121’a之中。更具體而言，錐形柱體122’b與直孔121’a之 間存在有一間隙G’，故穿設於直孔121’a中之錐形柱體 122’b即可進行偏擺移動。此外，油封127乃是設置於直孔 121’a之一内壁121’a’與煞車凸輪122’之錐形柱體122’b之 間，其可在常態下使錐形柱體122’b定位於直孔121’a之中 央處。 固定銷123是連接於盤體12Γ。 煞車臂130是連接於煞車凸輪122’之錐形柱體122’b。 至於本實施例之其他元件構造、特徵或運作方式均與 第一實施例相同，故為了使本案之說明書内容能更清晰易 懂起見，在此省略其重複之說明。 如上所述，當煞車導線140拉動煞車臂130而驅使煞 車凸輪122’之錐形柱體122’b作動時，錐形柱體122’b會 先旋轉一角度。此時，煞車凸輪122’之抵接頭部122a亦會 10 201249699 隨之旋轉該角度而以轉動之方式抵推第一煞車蹄片124及 第二煞車蹄片125,因而迫使第一煞車蹄片124及第二煞 車蹄片125以固定銷123為支點轉動而撐開以摩擦輪鼓 110。在此，第一煞車蹄片124會比第二煞車蹄片125優先 完全抵緊摩擦輪鼓110。接著，由於由於錐形柱體122’b 與直孔121’a之間存在有間隙G’，故穿設於直孔121’a中 之錐形柱體122’b會進行偏擺移動，因而可以迫使第二煞 車蹄片125更進一步以固定銷123為支點轉動而完全抵緊 摩擦輪鼓110,如第3B圖所示。同樣地，當錐形柱體122’b 在直孔121’a之中進行偏擺移動時，設置於直孔121’a之内 壁121’a’與煞車凸輪122’之錐形柱體122’b間的油封127 會受到壓迫而發生暫時的彈性變形。 綜上所述，由於本發明所揭露之鼓式煞車機構是利用 煞車凸輪與固定盤之間的配置變化來達成使第一煞車蹄片 及第二煞車蹄片皆能完全抵緊摩擦輪鼓之目的，故其整體 煞車制動效果可以被有效提升。 雖然本發明已以較佳實施例揭露於上，然其並非用以 限定本發明，任何熟習此項技藝者，在不脫離本發明之精 神和範圍内，當可作些許之更動與潤飾，因此本發明之保 護範圍當視後附之申請專利範圍所界定者為準。 201249699[ 第 圖； 圖式簡單說明】 1圖係顯示一 種習知之鼓式煞車機構之平面示意 _第2圖係顯示習知之鼓式煞車機 不意圖； 構之部份剖面及平面 態下林發社鼓車機構於—種運仙 狀態本發明之鼓以車機構於另—種運作 第4圖係顯示根據本發明之第 構之部份剖面及平面示意圖；以及 第5圖係顯示根據本發明之第 構之部份剖面及平面示意圖。 【主要元件符號說明】 —實施例之鼓式煞車機 二實施例之鼓式煞車機 1、100、100’〜鼓式煞車機構 10、110〜輪鼓 20、 120、120’〜固定盤 21、 121、121’〜盤體 21a、121’a〜直孔 22、 122、122’〜煞車凸輪 22a、122a〜抵接頭部 22b、122b〜直柱體 23、 123〜固定銷 24、 124〜第一煞車蹄片 12 201249699 25、 125〜第二煞車蹄片 26、 126〜拉伸彈簧 30、130〜煞車臂 40、140〜煞車導線 121a〜錐形孔 121a’、121’a’〜内壁 122’b〜錐形柱體 127〜油封 G、G’〜間隙 13201249699 VI. Description of the Invention: [Technical Field] The present invention relates to a drum type brake mechanism, and a drum type brake mechanism which can improve the brake effect of a brake.先前About [Prior Art] Please refer to Figures 1 and 2, a conventional one mainly includes a wheel drum 1 〇, a fixed disk 2 〇, and a Y 1 car mechanism 1 vehicle wire 40.滹3〇 and 煞 The drum 10 can be connected to a part of a wheel frame. ^ (not shown) or the wheel fixing plate 20 is sleeved in the drum 1〇, and a disk body 21, a brake cam 22, a fixing pin 23, a disk 2"" has a piece 24, a first Two-way car shoes 25 and two stretching ammunition = show that the disk body 21 has a constant hole 2la. The car is in the second part of the 22a and one acre; h: 舻? ancient 4, ' /, has a joint 2a and straight column The body 22b is directly connected to the abutment and the straight cylinder 22b is inserted in the straight hole of the disk body 21 in a rotating manner. The fixing pin 23 is connected to the disk body 2 % is relative to the second brake shoe piece 25. Here, as shown in Fig. i, the two ends of the first car pedal piece 24 abut against the abutment portion 22a and the fixing pin 23 of the brake cam 22, respectively. The two ends of the second car blade 25 are respectively abutted against the abutting portion 22a of the brake cam 22 and the fixing pin 23. As described above, the second car blade 24 and the first weigh shoe 25 can fix the pin 23 as a pivot point. In order to rotate, the friction drum 1〇 can be abutted according to the operation requirement, and the braking effect on the drum 10 (or the wheel) can be achieved. In addition, two 4 201249 699 The tension spring 26 is connected between the first brake shoe 24 and the second brake shoe 25, so that the two brake shoe 24 and the second brake shoe 25 are respectively held to abut against the brake The cam 22 abuts the joint portion 22a and the fixing pin 23. The brake arm 30 is a straight cylinder 22b connected to the brake cam 22. The brake wire 40 is connected to the brake arm 30. When the brake wire 40 pulls the brake arm 30 to drive the brake cam When the straight cylinder 22b of the 22 is actuated, the straight cylinder 22b is rotated by an angle. At this time, the abutting portion 22a of the brake cam 22 also rotates the angle to rotate the first brake shoe 24 and The second brake shoe 25 is thus forced to rotate the first brake shoe 24 and the second brake shoe 25 with the fixing pin 23 as a fulcrum to expand the friction drum 10, thereby achieving the drum 1 (or wheel) However, when the first brake shoe 24 and the second brake shoe 25 are pushed apart by the abutting portion 22a of the brake cam 22, the first brake is preferentially brought into full contact with the wheel. ":^, 2^ The entire brake wheel 22 can only be moved on the fixed plate 2 (or the disk body, The displacement movement cannot be performed, so the second turn piece === is in full contact friction with the drum 10. In other words, the friction area between the second brake shoe and the drum 1G is insufficient, thus causing the brake to brake. In view of the fact that the present invention provides a drum-type sensitization, the first shovel and the second shovel can be completely worn to enhance the overall braking effect. The present invention basically adopts the features as detailed below in order to solve the above problems. One embodiment of the present invention provides a drum brake mechanism comprising: a drum; a fixed disk, sleeved on The drum has a disc body, a brake cam, a fixing pin, a first brake shoe and a second brake shoe, wherein the disk body has a tapered hole, and the brake cam has a Abutting the connecting portion and the connecting body, the straight column system is connected to the abutting portion, and is inserted into the tapered hole of the disk body in a rotating and yaw manner, the fixed pin is connected to the disk Body, the first brake shoe The two ends of the first brake shoe are respectively abutted against the abutting portion of the brake cam and the fixing pin, and the two ends of the second brake shoe are respectively abutted with respect to the second brake shoe The abutting portion of the brake cam and the fixing pin; a straight arm body connected to the brake cam; and a brake wire connected to the brake arm, wherein the brake wire pulls the brake arm And driving the _ car cam to the straight (four) actuation, the abutting portion of the brake cam rots and yaws against the first shovel and the second shovel to force the first brake The shoe piece and the two φ door long-term music and a dry hoof piece rotate with the fixed sodium as a fulcrum to abut against the drum. According to the above embodiment, the fixing plate further has an oil seal, and the oil is disposed on the inner wall of the tapered hole and the straight cylinder of the car cam, and the disk has a straight hole, and the disk has a straight hole, The car cam has a further invention - the embodiment provides - a drum and a car mechanism, comprising: a two! two fixed plate, sleeved in the drum, and has - disk body, ',,", - fixed Lock, - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The shoe piece=:!, the first shoe piece is opposite to the abutting portion of the second jaw and the fixing pin, such as: cam:::: the abutting portion of the braking cam (four) is connected to The tapered cylinder of the brake cam; and a green 'car makes the: 'where' # The brake wire pulls the brake arm and the drive is rotated in a yaw manner to push the first fixed pin as a pivot point And the friction is rubbed against the drum...., the hoof... According to the above embodiment, the fixed plate has an oil seal, and the system is disposed at the straight The inner wall and the tapered cylinder of the brake cam are further in the present invention, the fixed disk further has at least a tensile cage, and the tension spring is coupled to the first brake shoe and the second The above-mentioned objects, features, and advantages of the present invention will become more apparent and obvious, and the preferred embodiments of the present invention are described in the accompanying drawings. For an embodiment, please refer to FIG. 3A and FIG. 3B. The drum brake mechanism 201249699 100 of the present embodiment mainly includes a drum 11〇, a fixed plate 12〇, an arm 13〇 and a brake wire 140. 110 may be connected to the wheel-wheel frame (not shown) or part of the wheel frame. As shown in Fig. 4, the fixed disk 12〇 is sleeved in the wheel drum, and the fixed disk 120 is fixed. There is a disk body 121, a brake cam I], a fixing pin 123, a first brake shoe 124, a second brake shoe 125, two tension springs 126 and an oil seal 127. In this embodiment The disk body 121 has a tapered hole 121a. The brake cam 122 has an abutting portion 122a and a The straight cylinder 122b is connected to the abutting portion 122a, and the straight cylinder 12 is inserted into the tapered hole of the disk body 121 in a rotating and yaw manner. More specifically, due to the straight There is a gap G between the cylinder 122b and the tapered hole 12u, so that the straight body 12沘 penetrating in the tapered hole 121a can be yawed. Further, the oil seal 27 is disposed on the tapered hole 12U. One of the inner wall 121a' and the hole of the straight cylinder 12 of the brake cam 122 can normally position the straight cylinder 122b at the center of the tapered hole 12la. The fixing pin 123 is connected to the disk body 12ι. The brake shoe 124 is relative to the second brake shoe IK. Here, as shown in FIGS. 3A and 3B, the two ends of the first brake shoe 124 are respectively abutted against the joint portion of the brake cam 122 and the fixing pin 123, and the ends of the shoe 125 are also They are respectively abutted against the brake cam 122 == a and the fixed pin 123. As described above, the 'first-turner shoe Π4 and the first-hand hoof blade 125 can fix the pin 123 as a rotating branch 'and thus can abut the friction wheel drum according to the operation need', 8 201249699 can achieve the drum drum 110 (or the wheel) In addition, the two tension springs 126 are connected between the first brake shoe 124 and the second brake shoe 125, which can make the first brake shoe 124 and the second brake shoe 125 The ends are respectively abutted against the abutting portion 122a and the fixing pin 123 of the brake cam 122. The brake arm 130 is a straight cylinder 122b connected to the brake cam 122. The brake wire 140 is connected to the brake arm 130. When the brake wire 140 pulls the brake When the arm 130 drives the straight cylinder 122b of the brake cam 122 to move, the straight cylinder 122b first rotates by an angle. At this time, the abutting portion 122a of the brake cam 122 also rotates the angle to push it in a rotating manner. The first brake shoe 124 and the second brake shoe 125 thereby force the first brake shoe 124 and the second brake shoe 125 to rotate with the fixing pin 123 as a fulcrum to expand the friction drum 110. Here, the first煞 蹄 片 124 will be better than the first The brake shoe 125 preferentially abuts against the friction drum 110. Then, since there is a gap G between the straight cylinder 122b and the tapered hole 121a, the straight cylinder 122b penetrating in the tapered hole 121a is biased. The pendulum moves, thereby forcing the second brake shoe 125 to further rotate against the friction wheel drum 110 with the fixing pin 123 as a fulcrum, as shown in Fig. 3B. Further, when the straight cylinder 122b is in the tapered hole 121a When the yaw movement is performed, the oil seal 127 provided between the inner wall 121a' of the tapered hole 121a and the straight cylinder 122b of the brake cam 122 is pressed and temporarily elastically deformed. The second embodiment is in this embodiment. The same components as those in the first embodiment are denoted by the same symbols. 9 201249699 As shown in FIGS. 3A and 3B, the drum brake mechanism 100' of the present embodiment also mainly includes a drum 110 and a fixing. The disc 120', the arm 130 and a brake wire 140. As shown in Fig. 5, the fixed disc 120' is sleeved in the drum 110, and the fixed disc 120' has a disc 121', a brake cam 122', a fixed pin 123, a first shovel 124. A second brake shoe 125, two tension springs 126 and an oil seal 127. In the embodiment, the disk body 12 has a straight hole 121'a. The brake cam 122' has an abutting portion 122a and a cone. a cylindrical body 122'b. The tapered cylindrical body 122'b is connected to the abutting portion 122a, and the tapered cylindrical body 122'b is inserted into the straight hole 121'a of the disk body 12 in a rotating and yaw manner. More specifically, there is a gap G' between the tapered cylinder 122'b and the straight hole 121'a, so that the tapered cylinder 122'b penetrating in the straight hole 121'a can be biased. Pendulum movement. In addition, the oil seal 127 is disposed between the inner wall 121'a' of the straight hole 121'a and the tapered cylinder 122'b of the brake cam 122', which can position the tapered cylinder 122'b under normal conditions. At the center of the straight hole 121'a. The fixing pin 123 is connected to the disk body 12A. The brake arm 130 is a tapered cylinder 122'b that is coupled to the brake cam 122'. The other components of the present embodiment are the same as those of the first embodiment, and therefore, in order to make the contents of the present specification clearer and easier to understand, the repeated description thereof will be omitted. As described above, when the brake wire 140 pulls the brake arm 130 to urge the tapered cylinder 122'b of the brake cam 122' to actuate, the tapered cylinder 122'b will first rotate an angle. At this time, the abutting portion 122a of the brake cam 122' is also 10 201249699, and the angle is rotated to push the first brake shoe 124 and the second brake shoe 125 in a rotating manner, thereby forcing the first brake shoe 124 And the second brake shoe 125 is rotated by the fixing pin 123 as a fulcrum to expand the drum drum 110. Here, the first brake shoe 124 will preferentially abut the friction drum 110 more preferentially than the second brake shoe 125. Then, since there is a gap G' between the tapered cylinder 122'b and the straight hole 121'a, the tapered cylinder 122'b penetrating in the straight hole 121'a is yawed, thereby The second brake shoe 125 can be forced to rotate further with the fixing pin 123 as a fulcrum to completely abut against the friction drum 110, as shown in Fig. 3B. Similarly, when the tapered cylinder 122'b is yawed in the straight hole 121'a, the inner wall 121'a' of the straight hole 121'a and the tapered cylinder 122' of the brake cam 122' are disposed. The oil seal 127 between b is subjected to compression and temporarily elastically deformed. In summary, the drum brake mechanism disclosed in the present invention utilizes the configuration change between the brake cam and the fixed disc to achieve that the first brake shoe and the second brake shoe can completely abut the friction drum. Purpose, so the overall brake effect can be effectively improved. Although the present invention has been disclosed in its preferred embodiments, it is not intended to limit the present invention, and it is possible to make some modifications and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims. 201249699[Picture; Simple description of the drawing] 1 The figure shows the plane diagram of a conventional drum type brake mechanism. The second figure shows the conventional drum type brake machine. The partial section and the plane state of the forest are not intended. The drum mechanism of the present invention is in a state in which the drum of the present invention is operated by the vehicle mechanism in another mode. FIG. 4 is a partial cross-sectional and plan view showing the structure according to the present invention; and FIG. 5 is a view showing the invention according to the present invention. A partial section and a plan view of the first part of the structure. [Description of main component symbols] - drum brake system of the second embodiment of the embodiment, drum brake machine 1, 100, 100' - drum brake mechanism 10, 110 - drum drum 20, 120, 120' - fixed disk 21, 121, 121'~disk body 21a, 121'a~ straight hole 22, 122, 122'~ brake cam 22a, 122a~ abutting portion 22b, 122b~ straight cylinder 23, 123~ fixing pin 24, 124~ first煞 蹄 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 ~ Tapered cylinder 127 ~ oil seal G, G' ~ gap 13