1314197 (1) 九、發明說明 【發明所屬之技術領域】 本發明’主要關於在機車所使用的變速機的換檔機構 ’尤其是關於變速機的換檔機構的改良，在藉由預定單位 角度的旋轉對變速機的換檔機構施加變速動作的變速鼓的 端部’設置繞著其軸線周圍排列的複數的從動銷；以讓因 應於換檔軸來自於中正位置的往復轉動而讓變速臂往復移 動的方式，使換檔軸連動於變速臂，該變速臂具有一對驅 動爪，該一對驅動爪是相對向且跨越著從動銷中互相鄰接 的兩支從動銷；藉由變速臂的往前移動，驅動爪會使與其 相對向的從動銷進給，使變速鼓旋轉預定單位角度。 【先前技術】 該變速機的換檔機構，如習知的揭示於專利文獻1的 技術。 〔專利文獻1〕 日本實公平5—95 66號公報 【發明內容】 〔發明欲解決的課題〕 在習知的變速機的換檔機構’如專利文獻1所揭示， 將一對的驅動爪一體地形成於變速臂’當變速臂往前移動 時，驅動爪會按壓在其前面相對向的從動銷而變速’當變 速臂回復移動時’上述驅動爪背面的斜面’藉由譲與其抵 -5- (2) 1314197 接的從動銷一邊滑動一邊通過，則變速臂結束回復移動。 期間，當驅動爪的背面離開從動銷時，變速臂會·撞擊,丨生地 抵接於從動銷的側面，而產生撞擊聲音，會迴響於曲軸箱 ，會成爲讓操縱者不適的撞擊聲音。 本發明，鑒於這種情形，其目的要提供一種變速機的 換檔機構，當進行換檔操作時，能避免變速臂與從動銷的 撞擊性的抵接，能夠預先防止產生撞擊聲音。 〔用以解決課題的手段〕 爲了達成上述目的，第1發明，在藉由預定單位角度 的旋轉而對變速機的換檔機構施加變速動作的變速鼓的端 部，設置有：排列於其軸線周圍的複數的從動銷；以讓因 應於換檔軸來自於中正位置的往復轉動而讓變速臂往復移 動的方式，使換檔軸連動於變速臂，該變速臂具有一對驅 動爪，該一對驅動爪是相對向且跨越著從動銷其中互相鄰 • 接的兩支從動銷；藉由變速臂的往前移動，其中一方的驅 動爪會使與其相對向的從動銷進給，使變速鼓旋轉預定單 位角度；在變速機的換檔機構，以可於：驅動爪的前面部 '相對向於從動銷的立起位置、與由從動銷的旋轉路線退去 的退去位置之間移動的方式，將驅動爪安裝於變速臂，並 且在該驅動爪連接著將驅動爪朝向上述立起位置彈壓的立 起彈簧，當變速臂回復移動時，藉由抵接於上述驅動爪背 面的從動銷，而可克服上述立起彈簧的彈壓力，使上述驅 動爪移動到上述退去位置。 -6- (3) 1314197 第2發明’針對上述第】發明’以讓該驅動爪可於上 述立起位置及退去位置之間轉動的方式，將上述驅動爪經 由樞支軸而安裝於上述變速臂。 第3發明，針對於上述第！或2發明，在上述一對驅 動爪，連接著：用來將上述一對驅動爪同時朝立起位置彈 壓的共通的立起彈簧的兩端。 第4發明’針對於上述第2發明，在上述變速臂，固 Φ 定設置有擋塊部，該擋塊部，用來限制上述驅動爪的立起 位置’且用來承受上述立起彈簧相對於該驅動爪的彈壓力 〔發明效果〕 藉由第1發明’當藉由換檔操作而進行變速臂的往復 移動時，藉由變速臂上的驅動爪的立起及退去動作，則能 讓變速鼓的從動銷進給，並且避免變速臂與從動銷的撞擊 性的抵接’能預先防止產生撞擊聲音。 藉由第2發明，是以可藉由樞支軸而於立起位置及退 去位置之間轉動的方式，將驅動爪安裝於變速臂，則驅動 爪在立起位置及退去位置之間的動作會很順暢，於是可充 分地減少立起彈簧的沉降荷重。 藉由第3發明，相對於兩驅動爪能用共通的一個立起 彈簧，所以有助於簡化構造。 藉由第4發明，藉由設置於變速臂的擋塊部，能確實 地限制驅動爪的立起位置，則能確實地利用驅動爪進行從 (4) 1314197 動銷的進給。 【實施方式】 實 檔 3 移 動 對 對 部 著 隔 滑 機 6b 5b 速 而 變 以下根據附圖所示的較佳實施例’來說明本發明的 施方式。 第1圖是本發明的第一實施例的機車用變速機的換 機構的側面圖，第2圖是第1圖的2 — 2線剖面圖，第 圖是第1圖的主要部分放大圖，第4圖是變速臂的往前 動時的作動說明圖，第5圖是變速臂的回復移動時的作 說明圖，第6圖是顯示本發明的第二實施例的與第3圖 應的圖，第7圖是顯示本發明的第三實施例的與第3圖 應的圖。 首先，開始進行第1圖〜第5圖所示的本發明的第 實施例的說明。 在第1圖及第2圖，在機車用引擎的曲軸箱1的上 ，可自由轉動地支承著變速鼓2，並且與其鄰接地支承 換檔導引軸3。在變速鼓2的外周，在長軸方向隔著間 形成有複數條的導溝4a、4b。在換檔導引軸3是可自由 動地嵌合著複數的換檔機構5a、5b的基部’在該換檔 構5a、5b的基部外周所一體地突出設置的導引銷6a、 ’是可滑動地卡合於上述導溝4a、4b。換檔機構5a、 ’其前端是卡合於曲軸箱1內的變速機的變速齒輪，變 鼓2的每次預定單位角度的旋轉會將沿著導溝4 a、4 b 移動的對應的變速齒輪予以換檔，藉由其反覆動作，將 -8- (5) 1314197 速機從空檔切換到最高檔位，或朝其相反方向進行切換。 在變速鼓2的其中一端固定著棘爪板7。該棘爪板7 ，在外周略等間隔地排列著複數的缺口 7 a、7 a…。在該棘 爪板7的其中一側方，棘爪臂9的基端部是藉由樞軸8而 可自由轉動地支承於曲軸箱1。在該棘爪臂9的前端，軸 支承著：可與複數的缺口 7a、7a…其中的一個卡合的滾子 9a，並且在樞軸8周圍安裝著：將該滾子9a朝向與缺口 7a的卡合方向彈壓的棘爪彈簧1〇。而棘爪板7、棘爪臂9 、及棘爪彈簧10，構成了 ：藉由使滾子9a彈壓卡合於缺 口 7a，來將變速鼓2保持在預定的旋轉位置的棘爪機構 11° 在棘爪板7，是藉由插入方式安裝著：突出於棘爪板 7的外端面且在外周方向等間隔地排列的複數的從動銷1 5 、15…，將該從動銷15、15…的外端按壓緊固的保持板 16，是藉由將該保持板16及棘爪板7的中心部貫穿的螺 拴17，而被固定於變速鼓2的端壁部。此時，涵蓋著變速 鼓2及棘爪板7，嵌合著用來限定兩者的相對位置的缺口 銷18。該棘爪板7及保持板16，是藉由一支螺栓17而固 定於變速鼓2。在第2圖中，圖號1 9是空檔檔位檢測開關 ，當變速鼓2來到空檔位置讓變速機成爲空檔狀態時會作 動，車輛的儀表板上的空檔顯示燈會點亮。 另一方面，在曲軸箱1的下部，是可自由旋轉地支承 著：在外端具備有換檔踏板（沒有圖示）的換檔軸20。在 換檔軸20，固定安裝著：在曲軸箱1內所配置的作動臂 -9- (6) 、1314197 21的基端部。該作動臂21，以預定的中正位置C爲起點 ，朝其前後方向往復轉動，在其作動臂21與曲軸箱1之 間，設置有：用來將作動臂21朝向上述中正位置C彈壓 的習知的中正回復機構22。 如第1圖及第3圖所示，在作動臂21的前端部’是 經由連結軸24而可相對自由轉動地連結著換檔臂25。在 該作動臂21及換檔臂25之間張設著臂部彈簧26，藉由該 φ 臂部彈簧26的彈壓力，換檔臂25會被彈壓成：與上述從 動銷1 5、1 5…群之中，鄰接的兩支從動銷1 5、1 5的外側 面抵接。 在該變速臂25，是隔著上述兩支從動銷15、15而設 ' 置有：其前面部27f互相相對向的一對驅動爪27、27。該 兩驅動爪27、27，是藉由樞支軸31、31而安裝於變速臂 25，且繞著樞支軸31往前轉動於：使前端爪部較變速臂 25的上面部更突出而與從動銷15相對向的立起位置A( # 參照第3圖及第4圖）、以及以使前端爪部由從動銷1 5、 1 5…的旋轉路線退去的方式而朝向變速臂25的上面部下 方移動的退去位置B (參照第5圖）之間；各驅動爪27 ' 的立起位置A，是藉由讓在驅動爪27、27所形成的擋塊 部28 ’抵接於在變速臂25所一體形成的擋塊部29所限制 。而且以將兩驅動爪2 7、2 7分別朝向立起位置A彈壓的 方式，在兩驅動爪2 7、2 7，在爪部與相反側，連接著•共 通的一條立起彈簧30的兩端。該立起彈簧30的沉降荷重 ’是設定成充分地小於上述臂部彈簧26的沉降荷重。 -10- (7) 1314197 兩驅動爪27、27的背面部27f’是形成在： 爲頂部的斜面。於是’各驅動爪27，在立起狀態 面部27f，來推動與其相對向的從動銷15，而當 背面部27f，與其相對向來進行按壓時’無法一 彈簧3 0延伸一邊朝向退去位置B側轉動而讓上 15進給。也就是說’各驅動爪27，僅具有單向 能。兩驅動爪2 7、2 7，其形狀及動作是對稱性的 φ 接著，針對第一實施例的作用來加以說明。 在作動臂21位於中正位置C的狀態，如第 ，變速臂25，是藉由臂部彈簧26的彈壓力而抵 銷15、15…群其中的兩支從動銷15、15的外側 ' 狀態的一對驅動爪2 7、2 7，是跨越於上述兩支毛 、1 5而相對向。棘爪臂9具有棘爪彈簧1 0的彈 滾子9a彈壓卡合於棘爪板7的一個缺口 7a ’來 2保持在該位置。 # 如第4圖所示，當藉由換檔踏板的踩踏操作 檔軸2 0，將作動臂2 1從中正位置C朝向例如箭 ' 轉動（往前移動）時，藉由讓其中一方的驅動爪 • 4圖是左方的驅動爪27)，推動與其前面部27f 其中一方的從動銷15，使變速鼓2旋轉預定角度 能讓變速機進行一階段的變速動作。此時，另一 爪27 (在第4圖是右方的驅動爪27 )，僅朝向 的從動銷15遠離的方向移動，而與變速機的變 關。 將爪部作 能以其前 以傾斜的 邊使立起 述從動銷 的進給機 〇 3圖所示 接於從動 面，立起 έ動銷15 壓力而使 將變速鼓 ，經由換 頭S方向 27 (在第 相對向的 單位，則 方的驅動 從相對向 速動作無 -11 - (8) 1314197 期間，棘爪臂9的滾子，不會伴隨著變速鼓2 旋轉，而使滾子9a從之前所卡合的缺口 7a移往相 口 7a，會將變速鼓2保持在新的旋轉位置。 如上述的其中一方的驅動爪27，在將其中一方 銷1 5進給而使變速鼓2旋轉預定單位角度的狀態 的從動銷1 5相對向於，該驅動爪27的傾斜的背面 〇 φ 因此，當解除來自於換檔踏板的操作力，藉由 復機構22使作動臂2 1回復移動到中正位置C時， 25也會伴隨著一對驅動爪27、27而回復移動，而 述其中一方的驅動爪27 (在第5圖是左側的驅動；1 ' ，會按壓其背後的傾斜於從動銷1 5的背面部27f， 邊使立起彈簧3 0延伸而一邊朝向退去位置B而繞 軸3 1轉動，而能從上述從動銷1 5遠離。 藉由該驅動爪27繞著樞支軸31的轉動，變速i ® 藉由臂部彈簧26的彈壓力，保持其與鄰接的兩支 1 5、1 5的外側面的抵接狀態，僅相對於從動銷1 5 ' ' 動，所以之間不會產生衝撞，能夠防止因爲衝撞所 * 衝撞聲音。 當使作動臂21，從中正位置C朝向與箭頭S 方向往復轉動時，變速臂會朝與上述相反的方向往 ，藉由另一方的驅動爪2 7的作動，則能使變速鼓 與上述相反的方向旋轉預定單位角度，在該情況， 25，藉由臂部彈簧26的彈壓力，能夠保持與鄰接 的上述 鄰的缺 的從動 ，其他 部27f 中正回 變速臂 此時上 \ 27) 所以一 著樞支 f 25 > 從動銷 ‘ 15滑 導致的 相反的 復移動 2朝向 變速臂 的兩支 -12- (9) 1314197 從動銷1 5、1 5的外側面的抵接狀態，在期間不會產 撞。 各驅動爪27，是以藉由樞支軸31而可於立起位 及退去位置B之間轉動的方式，安裝於變速臂25， 各驅動爪27的立起位置A及退去位置B之間的動作 暢，於是可充分地減少立起彈簧30的沉降荷重，而 著當變速臂25回復移動時，能防止由從動銷15分離， 立起彈簧3 0，藉由將其兩端連接於一對驅動爪 2 7，則能相對於兩驅動爪2 7、2 7用共通的一個驅動 而能有助於簡化構造。 接著針對第6圖所示的第二實施例來加以說明。 在該第二實施例，是將變速臂25直接固定於換 20。該變速臂25，在其中正位置C，在將換檔軸20 速鼓2的軸線之間連結的直線L上，配置成與前端部 的兩支從動銷1 5、1 5接近。在該變速臂2 5，是連接 將其朝向中正位置C彈壓的習知的中正回復機構22 該變速臂2 5的前端部，經由樞支軸3 1、3 1而安裝著 驅動爪27、27，該驅動爪27、27是隔著鄰接的兩支 銷1 5、1 5而相對向。圓柱狀的擋塊部29是藉由焊接 式而固定安裝於驅動爪27。其他構造，是與上述第一 例一樣，所以在第6圖中的與第一實施例對應的部分 用相同的參考圖號，省略重複的說明。 藉由該第二實施例，藉由使變速臂2 5從中正位 朝向箭頭S方向或與其相反的方向往復移動，則與上 生衝 置A 所以 很順 伴隨 27 ' 爪， 檔軸 及變 鄰接 著： 。在 iUtr —m 從動 等方 實施 ，是 置 c 述第 -13- (10) 1314197 一實施例同樣地’藉由驅動爪2 7、2 7、從動銷1 5、1 5… 及棘爪機構1 1的共同作用’則能譲變速鼓2產生預定單 位角度的旋轉。並且，在期間’轉動的變速臂25 ’並不會 抵接於從動銷，也不會產生衝撞聲音。而直接固定於換檔 軸20的變速臂25，是兼作爲上述第一實施例中的作動臂 21，而能讓構造簡化且讓換檔機構緊緻化。 接著，針對第7圖所示的第三實施例來加以說明。 在該第三實施例，直接固定安裝於換檔軸20的變速 臂25，是配置成橫截於變速鼓2的軸線。在該變速臂25 的前端部，是藉由樞支軸31、31而分別安裝著一對驅動 爪27、27，該一對驅動爪27、27是配置成：跨越於在換 檔軸20相反側鄰接的兩支從動銷15、15。而在變速臂25 的其中一側是一體地形成有輔助臂25a，在該輔助臂25a 連結著習知的中正回復機構22。 其他構造，與上述第二實施例一樣，所以在第7圖中 ，在與第二實施例對應的部分是附加相同的參照圖號，而 省略重複的說明。 藉由該第三實施例，藉由將變速臂25配置成橫截於 變速鼓2的軸線，則能將換檔軸20及變速鼓2的軸間距 離縮短，所以能使換檔機構更加緊緻化。 以上雖然說明了本發明的實施例，而本發明並不限定 於上述實施例，能在不脫離本發明的主旨的範圍進行各種 設計變更。例如，變速機的變速段數，並不限於如上述實 施例的四段，也可是三段或五段以上。而本發明也可適用 -14- (11) (11)1314197 於機車以外的車輛用引擎。 【圖式簡單說明】 第1圖是本發明的第一實施例的機車用變速機的換檔 機構的側面圖。 第2圖是第1圖的2 — 2線剖面圖。 第3圖是第1圖的主要部分放大圖。 第4圖是變速臂的往前移動時的作動說明圖。 第5圖是變速臂的回復移動時的作動說明圖。 第6圖是顯不本發明的第二實施例的與第3圖對應的 對應圖。 第7圖是顯示本發明的第三實施例的與第3圖對應的 對應圖。 【主要元件符號說明】 2 :變速鼓 5a、5b :換檔機構 1 5 :從動銷 2〇 :換檔軸 25 :變速臂 27 :驅動爪 27f :驅動爪的前面部 27r :驅動爪的背面部 29 =擋塊部 15- (12) (12)13141971314197 (1) Nine, the invention belongs to the technical field of the invention. The present invention is mainly concerned with the improvement of the shifting mechanism of the transmission used in the locomotive, especially regarding the shifting mechanism of the transmission, by a predetermined unit angle. Rotation of the end of the shifting drum to which the shifting mechanism of the transmission shifts the shifting mechanism Reciprocatingly moving the shifting shaft to the shifting arm, the shifting arm having a pair of driving claws that are opposite to each other and spanning two driven pins adjacent to each other in the driven pin; Moving forward, the drive pawl feeds the follower pin opposite thereto, rotating the shift drum by a predetermined unit angle. [Prior Art] The shifting mechanism of the shifting machine is disclosed in the technique of Patent Document 1 as is conventional. [Patent Document 1] Japanese Patent Publication No. Hei 5-95 (Convention) [Problem to be Solved by the Invention] In the shifting mechanism of the conventional transmission, as disclosed in Patent Document 1, a pair of driving claws are integrated. When the shift arm is moved forward, the drive pawl will press the follower pin in the front direction of the shifting arm and shift the gear when the shift arm resumes moving. - (2) When the follower pin of 1314197 passes while sliding, the shift arm ends to move back. During this period, when the back side of the driving claw is separated from the driven pin, the shifting arm will collide and abut against the side surface of the driven pin, and an impact sound will be generated, which will reverberate to the crankcase and become an impact sound that is uncomfortable to the operator. SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object thereof is to provide a shifting mechanism for a shifting machine which can prevent an impact of a shifting arm from a driven pin from being abutted when a shifting operation is performed, and can prevent an impact sound from being generated in advance. [Means for Solving the Problem] In order to achieve the above object, in the first aspect of the invention, the end portion of the shifting drum that applies the shifting operation to the shifting mechanism of the transmission by the rotation of the predetermined unit angle is provided on the axis a plurality of surrounding follower pins; the shifting arm is coupled to the shifting arm by a reciprocating movement of the shifting arm in response to the reciprocating rotation of the shifting shaft from the neutral position, the shifting arm having a pair of driving claws, the one The driving claws are opposite to each other and span the two driven pins of the driven pin; and by the forward movement of the shifting arm, one of the driving claws feeds the opposite driving pin to make the shifting drum Rotating a predetermined unit angle; the shifting mechanism of the transmission is movable between a rising position of the front portion of the driving pawl relative to the rising position of the driven pin and a retracted position retracted by the rotating path of the driven pin, Mounting the driving claw to the shifting arm, and connecting the driving claw to the rising spring that biases the driving claw toward the rising position, and when the shifting arm returns to move, by abutting The follower pin on the rear side of the driving claw can overcome the elastic pressure of the rising spring to move the driving claw to the retracted position. -6- (3) 1314197 According to a second aspect of the invention, the driving claw is attached to the shifting shaft via a pivot shaft so that the driving claw is rotatable between the rising position and the retracting position. arm. The third invention is directed to the above! According to a second aspect of the invention, the pair of driving claws are connected to both ends of a common rising spring for pressing the pair of driving claws toward the standing position at the same time. According to a fourth aspect of the invention, in the second aspect of the invention, the shift arm is fixedly provided with a stopper portion for restricting the rising position of the driving claw and for supporting the rising spring The spring pressure of the driving claws [Effect of the Invention] According to the first invention, when the shifting arm is reciprocated by the shifting operation, the driving claws on the shifting arm can be raised and retracted. The follower pin feed of the shift drum and the avoidance of the impact of the shift arm with the follower pin can prevent the impact sound from being generated in advance. According to the second aspect of the invention, the driving claw is attached to the shift arm so as to be rotatable between the standing position and the retracted position by the pivot shaft, and the driving claw is moved between the standing position and the retracted position. It will be smooth, so the settling load of the rising spring can be sufficiently reduced. According to the third aspect of the invention, a common standing spring can be used with respect to the two driving claws, which contributes to simplification of the structure. According to the fourth aspect of the invention, by providing the stopper portion of the shift arm, the standing position of the driving claw can be surely restricted, and the driving from the (4) 1314197 can be reliably performed by the driving claw. [Embodiment] The shifting of the shifting machine 3 to the speed of the partitioning machine 6b 5b will be described below with reference to the preferred embodiment shown in the drawings. 1 is a side view of a change mechanism of a locomotive gearbox according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line 2-4 of FIG. 1, and FIG. 1 is an enlarged view of a main portion of FIG. Fig. 4 is an explanatory view of the operation of the shift arm when it is moved forward, Fig. 5 is an explanatory view when the shift arm is moved back, and Fig. 6 is a view showing the second embodiment of the present invention and Fig. 3 Fig. 7 is a view showing a third embodiment of the present invention and Fig. 3; First, the description of the first embodiment of the present invention shown in Figs. 1 to 5 is started. In the first and second figures, the shift drum 2 is rotatably supported on the crankcase 1 of the locomotive engine, and the shift guide shaft 3 is supported adjacent thereto. On the outer circumference of the shift drum 2, a plurality of guide grooves 4a, 4b are formed in the longitudinal direction. The shift guide shaft 3 is a base portion of the shifting mechanism 5a, 5b that is movably fitted with a plurality of shifting mechanisms 5a, 5b. The guide pins 6a, 'which are integrally protruded on the outer circumference of the base of the shifting mechanisms 5a, 5b are The guide grooves 4a, 4b are slidably engaged. The shifting mechanism 5a, 'the front end thereof is a shifting gear of the transmission engaged in the crankcase 1, and each predetermined unit angular rotation of the variable drum 2 will shift the corresponding shifting along the guide grooves 4a, 4b. The gear is shifted, and by its repeated action, the -8-(5) 1314197 speed machine is switched from neutral to the highest gear or in the opposite direction. A pawl plate 7 is fixed to one end of the shift drum 2. The pawl plate 7 has a plurality of notches 7a, 7a, ... arranged at equal intervals on the outer circumference. On one of the pawl plates 7, the base end portion of the pawl arm 9 is rotatably supported by the crankcase 1 by a pivot 8. At the front end of the pawl arm 9, a roller 9a engageable with one of the plurality of notches 7a, 7a, ... is mounted, and around the pivot 8 is mounted: the roller 9a is oriented toward the notch 7a The pinch spring of the snapping direction is 1 〇. The pawl plate 7, the pawl arm 9, and the pawl spring 10 constitute a pawl mechanism 11 that holds the shift drum 2 in a predetermined rotational position by snapping the roller 9a into the notch 7a. In the pawl plate 7, a plurality of follower pins 15, 15, ... which are protruded from the outer end faces of the pawl plates 7 and are equally spaced in the outer circumferential direction are attached by inserting, and the follower pins 15, 15... The holding plate 16 that is fastened at the outer end is fixed to the end wall portion of the shift drum 2 by the threaded rod 17 that penetrates the center portion of the holding plate 16 and the pawl plate 7. At this time, the shift drum 2 and the pawl plate 7 are covered, and a notch pin 18 for defining the relative positions of the two is fitted. The pawl plate 7 and the retaining plate 16 are fixed to the shift drum 2 by a bolt 17. In Fig. 2, the figure number 19 is a neutral gear position detecting switch, and when the shifting drum 2 comes to the neutral position to make the transmission go into a neutral state, the neutral display lamp on the dashboard of the vehicle lights up. . On the other hand, the lower portion of the crankcase 1 is rotatably supported by a shift shaft 20 having a shift pedal (not shown) at the outer end. In the shift shaft 20, the base end portions of the actuator arms -9-(6) and 1314197 21 disposed in the crankcase 1 are fixedly mounted. The actuator arm 21 reciprocally rotates in the front-rear direction with a predetermined centering position C as a starting point, and between the actuator arm 21 and the crankcase 1, a biasing force for biasing the actuator arm 21 toward the neutral position C is provided. The known Zhongzheng reply agency 22. As shown in Figs. 1 and 3, the shift arm 25 is coupled to the distal end portion of the actuator 21 via the connecting shaft 24 so as to be relatively rotatable. An arm spring 26 is disposed between the actuator arm 21 and the shift arm 25, and the shift arm 25 is biased by the elastic pressure of the φ arm spring 26 to: and the follower pin 15 and 15 In the group, the outer sides of the two adjacent follower pins 15 and 15 abut. The shift arm 25 is provided with a pair of drive claws 27 and 27 whose front face portions 27f face each other across the two follower pins 15 and 15. The two driving claws 27 and 27 are attached to the shift arm 25 by the pivot shafts 31 and 31, and are rotated forward about the pivot shaft 31 to make the front end claw portion protrude from the upper surface portion of the shift arm 25. The standing position A (# referring to FIGS. 3 and 4) facing the follower pin 15 and the state in which the leading end claw portion is retracted by the rotation path of the follower pins 15 5, 15 ... toward the shift arm 25 The retracted position B (refer to FIG. 5) that moves below the upper surface; the standing position A of each of the driving claws 27' is abutted by the stopper portion 28' formed by the driving claws 27, 27 The stopper portion 29 integrally formed by the shift arm 25 is restricted. Further, in a manner of biasing the two driving claws 27 and 27 toward the standing position A, two of the two standing claws 30 are connected to the claw portions and the opposite sides of the two driving claws 27 and 27, respectively. end. The settling load ' of the rising spring 30 is set to be sufficiently smaller than the settling load of the arm spring 26. -10- (7) 1314197 The back surface portion 27f' of the two driving claws 27, 27 is formed as a slope which is a top portion. Then, the drive claws 27 push the driven pin 15 opposed thereto in the upright state surface portion 27f, and when the back surface portion 27f is pressed against the opposite direction, it is impossible to rotate toward the retracted position B side while the spring 30 extends. And let the 15 feed. That is to say, each of the driving claws 27 has only a unidirectional energy. The shape and operation of the two driving claws 2 7 and 2 7 are symmetrical. Next, the action of the first embodiment will be described. In a state where the actuator arm 21 is at the center position C, as in the first, the shift arm 25 is offset by the elastic pressure of the arm spring 26 to the outer side of the two follower pins 15, 15 of the group 15, 15 ... The pair of driving claws 2 7 and 27 are opposed to each other across the two hairs and 15 . The pawl arm 9 has a spring 9a of the pawl spring 10 that is snap-fitted to a notch 7a' of the pawl plate 7 to be held in this position. # As shown in Fig. 4, when the actuator arm 2 is rotated from the neutral position C toward, for example, the arrow ' (moving forward) by stepping the shift lever 20 of the shift pedal, by driving one of the drives The claws 4 are the left driving claws 27), and the driven pin 15 of one of the front portions 27f is pushed to rotate the shift drum 2 by a predetermined angle to allow the shifting machine to perform one-step shifting operation. At this time, the other pawl 27 (the drive pawl 27 on the right in Fig. 4) moves only in the direction away from the follower pin 15, and is changed to the speed changer. The claw portion can be connected to the driven surface with the inclined side of the front side of the feeder pin 3, and the pressure of the ram pin 15 is raised to make the shift drum pass the direction of the head S. 27 (In the opposite unit, the side drive is driven from the relative speed without -11 - (8) 1314197, the roller of the pawl arm 9 does not rotate with the shift drum 2, and the roller 9a Moving from the previously engaged notch 7a to the phase port 7a maintains the shifting drum 2 in a new rotational position. As one of the above-described driving claws 27, the one of the pins 15 is fed to the shifting drum 2 The follower pin 15 that is rotated in a state of a predetermined unit angle is opposed to the inclined back surface 〇φ of the drive pawl 27. Therefore, when the operating force from the shift pedal is released, the actuating arm 2 1 is moved back by the reset mechanism 22. When the middle position C is reached, 25 is also moved back along with a pair of driving claws 27, 27, and one of the driving claws 27 (in the fifth drawing, the driving on the left side; 1 ', will press the inclination behind it) The rear side portion 27f of the follower pin 15 is extended toward the rising spring 30 When the position B is removed, it is rotated about the shaft 31, and can be moved away from the above-mentioned driven pin 15. By the rotation of the driving claw 27 about the pivot shaft 31, the shifting speed i is maintained by the elastic pressure of the arm spring 26. The abutting state with the outer side faces of the two adjacent 15 and 15 is only moved relative to the follower pin 15'', so that no collision occurs between them, and it is possible to prevent the impact from being hit by the collision. 21, when reciprocating from the centering position C toward the direction of the arrow S, the shift arm will be in the opposite direction to the above, and by the operation of the other driving claw 27, the shift drum can be rotated in the opposite direction as described above. In this case, in this case, 25, by the elastic pressure of the arm spring 26, it is possible to maintain the follow-up of the adjacent neighboring one, and the other portion 27f is in the forward shift arm at this time. f 25 > Follow-up '15 slip caused by the opposite complex movement 2 toward the shift arm two -12- (9) 1314197 follower pin 15 5, 15 the outer side of the contact state, during the period will not collide Each of the driving claws 27 is erected by the pivot shaft 31 The method of rotating between the retracted positions B is attached to the shift arm 25, and the movement between the rising position A and the retracting position B of each of the driving claws 27 is smooth, so that the settling load of the rising spring 30 can be sufficiently reduced, and When the shift arm 25 is moved back, it can be prevented from being separated by the follower pin 15, and the spring 30 can be raised. By connecting the two ends thereof to the pair of driving claws 2, 7 can be used with respect to the two driving claws 27 and 27 One drive can help simplify the construction. Next, the second embodiment shown in Fig. 6 will be described. In this second embodiment, the shift arm 25 is directly fixed to the change 20. The shift arm 25 is disposed at a positive position C on a straight line L connecting the axes of the shift shaft 20 speed drum 2 so as to be close to the two follower pins 15 and 15 of the front end portion. The shift arm 25 is connected to a conventional center returning mechanism 22 that biases it toward the centering position C. The front end portion of the shift arm 25 is attached to the driving claws 27 and 27 via the pivot shafts 31 and 31. The drive claws 27 and 27 are opposed to each other via the adjacent two pins 15 and 15. The cylindrical stopper portion 29 is fixedly attached to the driving claw 27 by welding. Other configurations are the same as those in the first example described above, and therefore, the portions corresponding to those in the first embodiment in Fig. 6 are denoted by the same reference numerals, and the overlapping description will be omitted. According to the second embodiment, by shifting the shift arm 25 from the center position toward the direction of the arrow S or the direction opposite thereto, the A is flushed with the upper side so that it is smoothly accompanied by the 27' claw, the shift shaft and the adjacent Then: In the iUtr-m slave or the like, it is described in the thirteenth - (10) 1314197. The same embodiment "by driving the claws 2 7 , 2 7 , the follower pins 15 , 1 5 ... and the pawl mechanism The synergy of 1 1 enables the shift drum 2 to produce a rotation of a predetermined unit angle. Further, during the period "rotation of the shift arm 25" does not abut against the follower pin, and no collision sound is generated. Further, the shift arm 25 fixed directly to the shift shaft 20 serves as the actuating arm 21 in the first embodiment described above, and the structure can be simplified and the shift mechanism can be tightened. Next, the third embodiment shown in Fig. 7 will be described. In the third embodiment, the shift arm 25 directly fixed to the shift shaft 20 is disposed to cross the axis of the shift drum 2. At the front end portion of the shift arm 25, a pair of drive claws 27, 27 are respectively mounted by the pivot shafts 31, 31, and the pair of drive claws 27, 27 are disposed so as to be opposite to the shift shaft 20 Two follower pins 15, 15 adjacent to each other. On the one side of the shift arm 25, an auxiliary arm 25a is integrally formed, and the conventional intermediate return mechanism 22 is coupled to the auxiliary arm 25a. The other configuration is the same as that of the second embodiment described above. Therefore, in the seventh embodiment, the same reference numerals are attached to the portions corresponding to the second embodiment, and the overlapping description will be omitted. According to the third embodiment, by arranging the shift arm 25 to be transverse to the axis of the shift drum 2, the distance between the shift shaft 20 and the shift drum 2 can be shortened, so that the shift mechanism can be tightened. Towards. The embodiments of the present invention have been described above, and the present invention is not limited to the embodiments described above, and various design changes can be made without departing from the spirit and scope of the invention. For example, the number of shifting stages of the transmission is not limited to four stages as in the above embodiment, and may be three or more. The present invention is also applicable to a vehicle engine other than a locomotive -14- (11) (11) 1314197. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view showing a shifting mechanism of a locomotive gearbox according to a first embodiment of the present invention. Fig. 2 is a sectional view taken along line 2-4 of Fig. 1. Fig. 3 is an enlarged view of a main part of Fig. 1. Fig. 4 is an explanatory diagram of the operation when the shift arm is moved forward. Fig. 5 is an explanatory diagram of the operation when the shift arm is moved back. Fig. 6 is a view corresponding to Fig. 3 showing a second embodiment of the present invention. Fig. 7 is a view corresponding to Fig. 3 showing a third embodiment of the present invention. [Description of main components] 2: Shift drum 5a, 5b: Shift mechanism 1 5 : Follower pin 2: Shift shaft 25: Shift arm 27: Drive pawl 27f: Front portion 27r of the drive pawl: Back portion of the drive pawl 29 = block part 15-(12) (12) 1314197
3 Ο :立起彈簧 3 1 :樞支軸 A :驅動爪的立起位置 B :驅動爪的退去位置 -16-3 Ο : Stand-up spring 3 1 : pivot axis A : Stand-up position of the drive claw B : Retraction position of the drive claw -16-