1221503 (1) 玫、發明說明 【發明所屬之技術領域】 · 本發明係有關引擎的曲柄軸，特別是由曲柄軸箱所支 承的曲柄軸頸、及從該曲柄軸頸的端部朝半徑方向的外方 延伸的曲柄臂、及從該曲柄臂的前端部朝與曲柄軸頸平行 延伸而支承連桿的大端部之曲柄銷所組成，曲柄銷係有關 將朝與該中心線平行延伸的孔穿設之改良的曲柄軸。 、 【先前技術】 先前之曲柄軸係例如在日本實開昭5 4-44 8 3 8號公報 所揭示，既知將用來輕量化及供油的孔讓其中心通過曲柄 軸及曲柄銷的兩中心之直線上從曲柄銷的中心朝與曲柄軸 頸的相反側偏位的方式穿設於曲柄銷。 【發明內容】 〔發明所欲解決之課題〕 # 在如上述所構成之先前的曲柄軸，曲柄銷的重心藉由 比該中心更朝曲柄軸頸側偏位，與在曲柄銷的中心上穿設 同樣直徑的孔比較可減少曲柄銷的曲柄軸頸之中心周圍的 ’ 慣性力矩，相反地針對曲柄銷的肉厚，爲了讓承受爆發荷 > 重的部份之肉厚最小，很難讓曲柄銷的輕量化與強度確保 之兩全。 本發明係有鑑於上述情事而加以硏創，其目的爲提供 一種引擎的曲柄軸，謀求減少曲柄銷的曲柄軸頸之中心周 -4- (2) (2)1221503 圍的慣性力矩，且可確保期望之曲柄銷的強度。 〔用以解決課題之手段〕 爲了達成上述目的，本發明係一種引擎的曲柄軸’係 針對由：曲柄軸箱所支承的曲柄軸頸、及從該曲柄軸頸的 端部朝半徑方向的外方延伸的曲柄臂、及從該曲柄臂的前 端部與曲柄軸頸平行延伸而將連桿的大端部支承的曲柄銷 所組成，曲柄銷係將與該中心線平行延伸的孔穿設，其第 1特徵爲具備有：將上述孔的中心從通過曲柄軸頸及曲柄 銷的兩中心之 Y軸朝曲柄銷的公轉方向的前側偏位之引 擎的曲柄軸。 根據該第1特徵的話，藉由將上述孔的中心從γ軸 朝曲柄銷的公轉方向的前側偏位，在引擎的膨脹行程從活 塞經由連桿而對曲柄銷施加爆發荷重時，該爆發荷重係作 用在從曲柄銷的最薄肉部偏離的地方，而且伴隨著膨脹行 程進行而由於在爆發荷重作用之點的曲柄銷之肉厚會增加 ，故曲柄銷的強度高，就可謀求該耐久性的提升。另外藉 由上述孔之上述偏位配置就可讓該孔大徑化，曲柄銷的輕 量化，進而達成曲柄銷之有關曲柄軸頸中心的慣性力矩之 減少，且有助於獲得引擎之加速性的提升。 另外本發明係除了第1特徵以外，將上述孔連通在油 泵的吐出側，同時經由穿設在曲柄銷內的供油孔而連通於 連桿的大端部之內周面的第2特徵。 根據該第2特徵的話，可將上述孔利用於用來潤滑連 -5- (3) (3)1221503 桿的大端部之內周面的油孔。 而且本發明係除了第1特徵以外，更將上述孔的中心 在曲柄銷的中心從與上述Y軸直交的X軸朝反曲柄軸頸 側偏位，且將該孔連通於油泵的吐出側，同時在通過該孔 的中心及曲柄銷的中心的直線上經由穿設於曲柄銷的薄肉 部之供油孔連通到連桿的大端部之內周面的第3特徵。 根據該第3特徵的話，利用對上述孔的中心之Y軸 及X軸的上述偏位、與向曲柄銷的薄肉部穿設的供油孔 ，曲柄銷的重心係位在比該曲柄銷的中心更靠近曲柄軸頸 ，因此使曲柄銷之有關曲柄軸頸的中心之慣性力矩減少而 有助於獲得引擎之加速性的提升。而且到上述供油孔的曲 柄軸頸之中心的迴轉半徑大，所以在該供油孔讓離心力對 油有效地起作用，就可良好地進行潤滑連桿的大端部之內 周面。 另外本發明係除了第3特徵以外，將曲柄臂與曲柄軸 頸一體地形成，且將曲柄銷壓入於裝設在該曲柄臂的連結 孔，並且藉由該壓入位置設定上述孔及供油孔的位置之第 4特徵。 根據該第4特徵的話，利用調整曲柄銷的壓入位置， 就可自由地設定對於曲柄銷的孔之中心的Y軸及X軸之 偏位量或供油孔的位相，可提高泛用性。 另外本發明係除了第1特徵以外，將上述孔的中心配 置於曲柄銷的中心與上述Y軸直交的X軸上爲第5特徵 -6 - (4) (4)1221503 根據該第5特徵的話，不論曲柄銷之孔存在與否，引 擎的膨脹行程中，可充分地將在爆發荷重作用之點的曲柄 銷之肉厚增厚，且更可將曲柄銷的強度提高，而謀求其耐 久性更加提升。 另外，本發明係除了第5特徵以外，將上述孔連通在 油泵的吐出側，同時在從上述X軸朝反曲柄軸頸側偏位 的位置經由穿設於曲柄銷的供油孔而連通於連桿的大端部 之內周面爲第6特徵。 根據該第6特徵的話，即使上述孔位在X軸上，上 述供油孔藉由從X軸朝反曲柄軸頸側偏位而裝設在曲柄 銷上，曲柄銷的重心係位在較該曲柄銷的中心更靠近曲柄 軸頸，因此讓曲柄銷之有關曲柄軸頸中心的慣性力矩減少 ，而可謀求引擎之加速性的提升。 【實施方式】 以下根據添附圖面所示之本發明之一實施例說明本發 明的實施形態。 第1圖係具備本發明的第1實施例的曲柄軸之機車用 引擎的縱剖面圖，第2圖係第1圖之線2-2的剖面圖，第 3圖係第2圖之線3 - 3的剖面圖，第4圖係第3圖之線4 -4的剖面圖，第5圖係第3圖之線5 - 5的剖面圖，第6圖 係第1圖之6部放大圖，第7圖係第6圖之線7 - 7的剖面 圖，第8圖係顯示本發明的第2實施例，與第6圖的對應 剖面圖，第9圖係第8圖之線9 - 9的剖面圖，第1 0圖係 (5) (5)1221503 顯示本發明的第3實施例，與第9圖的對應剖面圖。 首先，在第1〜5圖中，搭載於機車的引擎E，係具 備有當做引擎本體的曲柄軸箱1、及朝該曲柄軸箱1的前 端以前傾姿態所結合的汽缸體（cylinder block ) 2、及接 合在該汽缸體2的前端之汽缸蓋（cylinder head) 3’且 曲柄軸箱1與汽缸體2係藉由包圍汽缸體2的汽缸內徑（ cylinder bore) 2a 的 4 支螺樁（stud bolt) 4、4…相互地 結合。 曲柄軸5係在曲柄箱1的左右之曲柄軸頸支持壁1 a 、lb隔著滾珠軸承6a、6b所支承，且來讓在該曲柄軸5 隔著連桿7而連接的活塞8嵌裝於汽缸內徑2 a內，並且 於汽缸蓋3裝設有火星塞9及汽門機構10，而且讓覆蓋 該汽門機構1〇的頭罩（head cover) 11接合在汽缸蓋3 的前端面。 在曲柄軸箱1的左外側壁讓傳動外罩1 2接合，且讓 皮帶式的無段變速機T配設在此等之間所規劃成的變速箱 1 3內。 如第3圖所示，曲柄軸箱1係從曲柄軸5藉由減速齒 輪組14、14’而讓驅動的餘擺線（trochoid)型之油泵15 安裝。該油泵1 5係由於從曲柄軸箱1的底部之油集中處 將潤滑油抽上來而從吐出口 1 5 a吐出，故從該吐出口 1 5 a 吐出的油係通過曲柄軸箱1的側壁之朝前油路2 0，而上 升通過汽缸體2的後端面的朝上油溝2 1。通過朝上油溝 2 1之油係經過將最上部的1支螺樁4完全插通汽缸體2 -8- (6) (6)!2215〇3 與汽缸盖3所形成之一連串的螺检孔1 9 ’而流入於上述 汽門機構1〇的搖動軸（rocker shaft) l〇a的油孔22，且 從供油孔23噴出而潤滑搖動臂（rocker arm)等。另外流 入於螺栓孔1 9的油之一部份係經由汽缸體2的傾斜油路 24，且由上升通過頭罩丨1端面的油溝25朝該頭罩1丨上 壁的朝前油路2 6移動，並且從噴油孔2 8噴出，而從上部 將汽門機構1 〇潤滑。 另外流入汽缸體2後端面的上下方向溝2 1之油的另 一部份係從該溝2 1的途中迎向曲柄軸箱1的右方之曲柄 軸頸支持壁1 b的朝後油路2 8，且被供給於曲柄軸5周圍 的潤滑。 其次，連帶參照第6圖及第7圖詳細說明有關曲柄軸 5的構成。 曲柄軸5係具備有：隔著左右之上述滾珠軸承6a、 6 b而被支承在曲柄軸箱1的左右之曲柄軸頸支持壁1 a、 lb的一對之曲柄軸頸5j a、5jb、及一體地形成在這些曲 柄軸頸5 j a、5 j b之互相對向的端部而朝半徑方向的外方 延伸之一對的曲柄臂 5wa、5wb。這些曲柄臂 5wa、5wb 的前端部係個別穿設有與曲柄軸頸5 j a、5 j b平行的連結 孔30，且讓曲柄銷5p的兩端部壓入於這些連結孔30內 ，如此兩曲柄臂5 wa、5 wb係藉由曲柄銷5p相互地被連 結成一體。曲柄銷5p係預先朝連結孔30壓入，讓連桿7 的大端部7a隔著滾針軸承3 1嵌裝在其外周。 另外曲柄銷5p係預先穿設有用來輕量化及供油的孔 -9- (7)1221503 3 2。該孔3 2的中心C 3係從通過曲柄軸頸5 j a、5 j b及 柄銷5p的兩中心C1、C2的Y軸朝曲柄銷5p的公轉方 R前側偏位距離e ’並且於曲柄銷5p的中心C2從與γ 直交的X軸的反曲柄軸頸5j a、5jb側’也就是以從曲 軸頸5 j a、5 j b朝離開的方向偏位距離e ’的方式配置。 後，在通過孔3 2的中心C 3及曲柄銷5 p的中心C 2的 線L上朝曲柄銷5 p的薄肉部3 3，穿設有將孔3 2連通 連桿7的大端部7a之內周面的供油孔34。 孔3 2係在曲柄銷5 p的一端面開口’且在其開口側 曲柄臂5 wb的外側面係形成有比曲柄銷5 p更朝半徑方 的外方延伸的環狀之安裝凹部35，且在該安裝凹部35 油收付板3 6鉚接而被固著。該油收付板3 6爲環狀且爲 形，而將孔3 2的開口部之一部份覆蓋的方式配置。 另一方面，具有上述朝後油路2 8的曲柄軸頸支承 1 b係形成有朝曲柄銷5p側突出而圍繞於油收付板3 6 筒狀小突起3 7，另外在該曲柄軸頸支承壁1 b的支承滾 軸承6b之軸承外圜的內周面係裝設有將上述朝後油路 連通於筒狀小突起3 7的內周側之軸方向油溝3 8。 接著，說明該實施例之作用。 引擎E之運轉中，從油泵1 5吐出而通過曲柄軸頸 承壁1 b的朝後油路2 8的油，係經由軸方向油溝3 8而 入於油收付板3 6的內側，且從此處移動到曲柄銷5 p的 3 2 ’藉由離心力的作用從供油孔3 4噴出，而潤滑滾針 承3 1或連桿7的大端部7a之內周面。 曲 向 軸 柄 妖 ✓ ΐ、、 直 於 的 向 讓 碟 壁 的 珠 28 支 流 孔 軸 -10- (8) (8)1221503 可是，曲柄銷5p的孔32之中心C3係如以上述的方 式，由於從通過曲柄軸頸5 j a、5 j b及曲柄銷5 p的兩中心 C1、C 2的Y軸之曲柄銷5 p的公轉方向R前側；及在曲 柄銷5 p的中心C 2從與Y軸直交的X軸之曲柄軸頸5 j a ' 5 j b側偏位配置，活塞8來到上死點，從活塞8經由連桿 7施加爆發荷重於曲柄銷5p時，該爆發荷重係作用於從 曲柄銷5 p的最薄肉部偏離的場所，而且由於隨著膨脹行 程進行而在爆發荷重作用之點的曲柄銷5 p的肉厚係進行 增加，故可謀求曲柄銷5 p的強度高，其耐久性提高。 另外藉由孔3 2的中心C 3從X軸朝反曲柄軸頸5 j a、 5jb側偏位，以及在曲柄銷5p的薄肉部33裝設有供油孔 34，曲柄銷5p的重心係位在比該曲柄銷5p的中心C2更 靠近曲柄軸頸5ja、5jb，因此曲柄銷5p之有關曲柄軸頸 5 j a、5 j b的中心C 1之慣性力矩，係由於比配置在曲柄銷 5p的中心C2的孔32及同徑的孔更小，故有助於獲得引 擎E的加速性提升。 而且因爲供油孔34到曲柄軸頸5j a、5jb中心的旋轉 半徑大，故可在該供油孔3 4讓離心力有效地作用在油上 而良好地進行連桿7之大端部7a的內周面等之潤滑。 另外曲柄軸5係由於將曲柄銷5p壓入於相對向的曲 柄臂5 wa、5 wb之連結孔而構成的組合，藉由調整曲柄銷 5 p的壓入位置，可將對於曲柄銷5 p的孔3 2之中心C 3的 Y軸及X軸之偏位量或供油孔3 4的相位自由地設定，且 可提高泛用性。 -11 - 1221503 Ο) 接著，藉由第8圖及第9圖說明本發明之第2實施例 〇 該第2實施例的曲柄軸5係藉由鍛造等將曲柄軸頸 5ja、5jb ;曲柄臂5 wa、5 wb以及曲柄銷5p —體成形，而 且伴隨隔著金屬軸承3 1 ’支承在曲柄銷5p的連桿7之大 端部7a係分配成二部份構造。 在上述曲柄銷5 p，穿設在與其中心線平行的孔3 2係 從Y軸朝曲柄銷5p的公轉方向R前側偏位距離e而配置 在X軸上。另外在曲柄銷5p，讓連通上述孔3 2於連桿7 的大端部7a之內周面的供油孔34’以橫越曲柄銷5p的方 式穿設，且此時，供油孔34’係從X軸朝反曲柄軸頸5ja 、5jb側偏位而配置。 其他的構成係由於與前實施例同樣，故第8圖及第9 圖中，在與前實施例之對應部份係付加相同的參照符號而 省略其說明。 根據該第2實施例的話，不論在曲柄銷5 p之孔3 2的 存在與否，引擎的膨脹行程中，可讓在爆發荷重作用的點 之曲柄銷5 p的肉厚足夠厚，可謀求將曲柄銷5 p的強度更 高，而其耐久性更提升。 而且上述孔3 2即使在X軸上位置’由於讓供油孔 3 4，從X軸朝反曲柄軸頸5 j a、5 j b側偏位而裝設在曲柄銷 5p，故該狀況，曲柄銷5p的重心係位在比該曲柄銷5P的 中心C2更靠近曲柄軸頸5ja、5jb ’因此曲柄銷5ρ之關方< 曲柄軸頸5 j a、5 j b的中心C 1之慣性力矩變小’所以有助 -12 - (10) (10)1221503 於獲得引擎E的加速性之提升。 最後，藉由第1 〇圖說明關於本發明的第3實施例。 該第3實施例係在曲柄銷5p，將穿設在與其中心線 平行的孔3 2在X軸上從Y軸朝曲柄銷5 p的公轉方向R 前側距離e偏位配置之點，係雖然與上述第2實施例沒有 不同，惟將該孔3 2在確保曲柄銷5 p之預定強度而且比第 2實施例的孔3 2形成更大徑之點不同。也就是在曲柄銷 5p的中心C2，考慮穿設對曲柄銷5p賦予爆發荷重所可承 受之最小肉厚之大的孔03 2的情況。一面確保其最小肉厚 ，一面爲了形成比該中心孔〇32將上述偏位孔32形成更 大徑，故將偏位孔32以讓該圓周通過X軸與中心孔032 的圓周的交點之方式形成。 其他的構成係因爲與第2實施例同樣，故第1 0圖中 ，在與第2實施例之對應部份係付加相同的參照符號而省 略其說明。 根據該第3實施例的話，不使曲柄銷5 p的強度降低 又可將偏位孔3 2大徑化，而可謀求輕量化’此時，因爲 曲柄銷5p之有關曲柄軸頸5ja、5jb的中心C1之慣性力 矩也變小，有助於獲得引擎E的加速性之提升。 本發明並不限定於上述實施例，只要不脫離其要旨之 範圍下可以進行各種設計變更。 〔發明效果〕 根據如以上本發明的第1特徵的話，由曲柄軸箱所支 -13- (11) (11)1221503 承的曲柄軸頸、及從該曲柄軸頸的端部朝半徑方向的外方 延伸的曲柄臂、及從該曲柄臂的前端部與曲柄軸頸平行延 伸而支承連桿大端部的曲柄銷所組成，曲柄銷係穿設有與 該中心線平行延伸的孔，在引擎的曲柄軸之中，由於將上 述孔的中心從通過曲柄軸頸以及曲柄銷的兩中心的 Y軸 朝曲柄銷的公轉方向前側偏位，故在引擎的膨脹行程從活 塞經由連桿而施加在曲柄銷的***荷重時，該爆發荷重係 作用在從曲柄銷的最薄肉部偏離的地方，而且因爲隨著膨 脹行程進行而在爆發荷重作用之點的曲柄銷的肉厚增加， 可謀求曲柄銷的強度高，且其耐久性提高。另外藉由上述 孔的上述偏位配置，可讓該孔大徑化，且曲柄銷輕量化， 進而達到曲柄銷之有關曲柄軸頸的慣性力矩之減少，且有 助於獲得引擎的加速性之提升。 另外根據本發明的第2特徵的話，除了第1特徵以外 ，因爲將上述孔連通在油泵的吐出側，同時經由穿設在曲 柄銷內的供油孔而連通於連桿的大端部之內周面，故可將 上述孔利用於用來潤滑連桿的大端部之內周面的油孔。 並且根據本發明的第3特徵的話’除了第1特徵以外 ，更將上述孔的中心在曲柄銷的中心從與上述γ軸直交 的X軸朝反曲柄軸頸側偏位，且將該孔連通於油泵的吐 出側，同時因爲在通過該孔的中心及曲柄銷的中心的直線 上經由穿設於曲柄銷的薄肉部之供油孔而連通於連桿的大 端部之內周面，故曲柄銷的重心係位在比該曲柄銷的中心 更靠近曲柄軸頸，因此可謀求使曲柄銷之有關曲柄軸頸中 -14- (12) (12)1221503 心的慣性力矩減少而引擎的加速性提升。而且因爲上述供 、 油孔到曲柄軸頸中心之旋轉半徑大’故在該供油孔讓離心 · 力有效果地作用於油，而可良好地進行潤滑連桿的大端部 之內周面。 並且根據本發明的第4特徵的話，除了第3特徵以外 ，因爲將曲柄臂一體地形成在曲柄軸頸上，將曲柄銷壓入 於裝設在該曲柄臂的連結孔，且利用該壓入位置將前述孔 · 及供油孔的位置設定，藉由調整曲柄銷的壓入位置，就可 φ 自由地設定對於曲柄銷的孔之中心的Y軸及X軸之偏位 量或供油孔的位相，可提高泛用性。 並且根據本發明的第5特徵的話，除了第1特徵以外 ，因爲將上述孔的中心配置在曲柄銷的中心與上述 Y軸 直交的X軸上，不論曲柄銷之孔存在與否，引擎的膨脹 行程中，可充分地將在爆發荷重作用之點的曲柄銷之肉厚 增厚，且更可將曲柄銷的強度提高，而謀求其耐久性更加 提升。 φ 並且根據本發明的第6特徵的話，除了第5特徵以外 ，因爲將上述孔連通在油泵的吐出側，同時在從上述X 軸朝反曲柄軸頸側偏位的位置經由穿設於曲柄銷的供油孔 - 而連通於連桿的大端部之內周面，故即使上述孔位在X 軸上，曲柄銷的重心係位在比該曲柄銷的中心更靠近曲柄 軸頸，因此曲柄銷之有關曲柄軸頸中心的慣性力矩減少， 而可謀求引擎之加速性的提升。 -15- (13) (13)1221503 【圖式簡單說明】 第1圖係具備有本發明的第1實施例之曲柄軸的機車 用引擎的縱剖面圖。 第2圖係第1圖的線2 - 2之剖面圖。 第3圖係第2圖的線3-3之剖面圖。 第4圖係第3圖的線4 - 4之剖面圖。 第5圖係第3圖的線5 - 5之剖面圖。 第6圖係第1圖的部份6之放大圖。 第7圖係第6圖的線7 - 7之剖面圖。 第8圖係顯示本發明的第2實施例，與第6圖的對應 剖面圖。 第9圖係第8圖的線9-9之剖面圖。 第1 0圖係顯示本發明的第3實施例，與第9圖的對 應剖面圖。 〔圖號說明〕 C 1 曲 柄軸 頸 的 中 心 C2 曲 柄銷 的 中 心 C3 曲 柄銷 的 孔 之 中 心 E 引 擎 L 直 線 R 曲 柄銷 的 公 轉 方 向 1 曲 柄軸 箱 5 曲 柄軸 -16- (14)1221503 5ja、5jb 曲柄軸頸 5p 曲柄銷 5 wa、5 wb 曲柄臂 7 連桿 7 a 大端部 3 0 連結孔 32 Λ o 曲柄銷的孔 曲柄銷的薄肉部 34 、 34” 供油孔 -17-1221503 (1) Description of the invention [Technical field to which the invention belongs] · The present invention relates to a crank shaft of an engine, particularly a crank journal supported by a crank shaft box, and a radial direction from an end of the crank journal. It consists of a crank arm that extends outward and a crank pin that extends from the front end of the crank arm to the large end of the connecting rod and extends parallel to the crank journal. The crank pin is about to extend parallel to the centerline. Improved crank shaft through holes. [Prior art] For example, a conventional crank shaft system is disclosed in Japanese Utility Model Publication No. 5 4-44 8 3 8 and it is known that a hole for weight reduction and oil supply has its center passing through both the crank shaft and the crank pin. The straight line of the center is inserted into the crank pin in such a manner as to be offset from the center of the crank pin toward the opposite side of the crank journal. [Summary of the Invention] [Problems to be Solved by the Invention] # In the previous crank shaft configured as described above, the center of gravity of the crank pin is deviated toward the crank journal side from the center, and is inserted in the center of the crank pin. Holes of the same diameter can reduce the moment of inertia around the center of the crank pin of the crank pin. Conversely, the meat thickness of the crank pin is the opposite. In order to minimize the meat thickness of the heavy parts that bear the burst load, it is difficult to make the crank The weight and strength of the pin are both guaranteed. The present invention has been made in view of the above circumstances, and an object thereof is to provide a crankshaft of an engine, so as to reduce the center of inertia moment around the crank journal of the crankpin, and to reduce the moment of inertia around the crankpin. Ensure the desired strength of the crank pin. [Means for solving the problem] In order to achieve the above object, the present invention relates to a crankshaft of an engine, which is directed to a crank journal supported by a crankcase, and a radial direction outward from an end of the crank journal. It consists of a crank arm that extends squarely, and a crank pin that extends from the front end of the crank arm parallel to the crank journal and supports the large end of the connecting rod. The crank pin is threaded through a hole that extends parallel to the centerline. The first feature is a crank shaft of an engine including a center of the hole shifted from a Y-axis passing through the two centers of the crank journal and the crank pin toward the front side in the revolution direction of the crank pin. According to this first feature, when the center of the hole is shifted from the γ axis toward the front side of the revolution direction of the crank pin, the explosive load is applied to the crank pin when the expansion stroke of the engine is applied from the piston through the connecting rod. It is applied at a place deviating from the thinnest meat portion of the crank pin, and as the expansion stroke progresses, the meat thickness of the crank pin increases at the point where the burst load acts, so the strength of the crank pin is high, and the durability can be sought Promotion. In addition, the above-mentioned offset arrangement of the hole can make the hole larger in diameter and reduce the weight of the crank pin, thereby achieving a reduction in the moment of inertia of the crank pin related to the center of the crank journal, and contributing to the acceleration of the engine. Promotion. In addition to the first feature, the present invention is a second feature in which the above-mentioned hole communicates with the discharge side of the oil pump and communicates with the inner peripheral surface of the large end portion of the connecting rod through an oil supply hole provided in the crank pin. According to this second feature, the above-mentioned hole can be used for lubricating the oil hole on the inner peripheral surface of the large end portion of the rod. Furthermore, in addition to the first feature, the present invention further shifts the center of the hole at the center of the crank pin from the X-axis orthogonal to the Y-axis toward the inverse crank journal side, and communicates the hole to the discharge side of the oil pump. At the same time, the third feature of communicating with the inner peripheral surface of the large end portion of the connecting rod via a oil supply hole passing through the thin meat portion of the crank pin on a straight line passing through the center of the hole and the center of the crank pin. According to this third feature, the center of gravity of the crank pin is located at a position higher than that of the crank pin by using the above-mentioned offset of the Y-axis and X-axis of the center of the hole and the oil supply hole penetrating the thin meat portion of the crank pin. The center is closer to the crank journal, so the inertia moment of the center of the crank journal related to the crank journal is reduced, which helps to improve the acceleration of the engine. In addition, the radius of rotation to the center of the crank journal of the oil supply hole is large, so that the centrifugal force effectively acts on the oil in the oil supply hole, and the inner peripheral surface of the large end portion of the connecting rod can be lubricated well. In addition to the third feature of the present invention, the crank arm is integrally formed with the crank journal, the crank pin is pressed into a connecting hole provided in the crank arm, and the hole and the supply hole are set by the pressing position. The fourth feature of the position of the oil hole. According to this fourth feature, by adjusting the press-in position of the crank pin, it is possible to freely set the offset amount of the Y axis and the X axis with respect to the center of the hole of the crank pin or the phase of the oil supply hole, which can improve versatility. . In addition to the first feature, the present invention is the fifth feature in which the center of the hole is arranged on the X axis perpendicular to the Y axis of the center of the crank pin.-6-(4) (4) 1221503 According to the fifth feature Regardless of the presence or absence of the hole of the crank pin, the flesh of the crank pin at the point where the explosive load acts can be sufficiently thickened during the expansion stroke of the engine, and the strength of the crank pin can be increased to achieve its durability. Improved even more. In addition, in addition to the fifth feature, the present invention communicates the above-mentioned hole on the discharge side of the oil pump, and communicates at a position deviated from the X-axis toward the inverse crank journal side via an oil supply hole provided in the crank pin. The inner peripheral surface of the large end portion of the link has a sixth feature. According to this sixth feature, even if the hole position is on the X axis, the oil supply hole is installed on the crank pin by being deviated from the X axis toward the inverse crank journal side, and the center of gravity of the crank pin is positioned more than that. The center of the crank pin is closer to the crank journal, so the moment of inertia of the center of the crank pin related to the crank journal is reduced, and the acceleration of the engine can be improved. [Embodiment] An embodiment of the present invention will be described below based on an embodiment of the present invention shown in the accompanying drawings. FIG. 1 is a longitudinal sectional view of a locomotive engine including a crankshaft according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is taken along line 3 of FIG. 2. -3 sectional view, Fig. 4 is a sectional view of line 4-4 of Fig. 3, Fig. 5 is a sectional view of line 5-5 of Fig. 3, and Fig. 6 is an enlarged view of part 6 of Fig. 1 Fig. 7 is a sectional view taken along line 7-7 of Fig. 6, and Fig. 8 is a sectional view corresponding to Fig. 6 of the second embodiment of the present invention. Fig. 9 is taken along line 9 of Fig. 8- A cross-sectional view of FIG. 9 is a cross-sectional view corresponding to FIG. 9, showing the third embodiment of the present invention in FIG. 10 (5) and (5) 1221503. First, in Figs. 1 to 5, the engine E mounted on a locomotive is provided with a crankshaft box 1 serving as an engine body, and a cylinder block (cylinder block) coupled forwardly toward the front end of the crankshaft box 1. 2. Cylinder head 3 'which is connected to the front end of the cylinder block 2 and the crankcase 1 and the cylinder block 2 are 4 screw piles surrounding the cylinder bore 2a of the cylinder block 2 (Stud bolt) 4, 4, ... are combined with each other. The crank shaft 5 is supported on the left and right crank journal support walls 1 a and 1 b of the crank case 1 via ball bearings 6 a and 6 b, and a piston 8 connected to the crank shaft 5 via a connecting rod 7 is fitted. A spark plug 9 and a valve mechanism 10 are installed in the cylinder inner diameter 2 a, and a head cover 11 covering the valve mechanism 10 is joined to a front end surface of the cylinder head 3. . A transmission cover 12 is engaged on the left outer side wall of the crank case 1, and a belt-type stepless speed changer T is disposed in the gearbox 13 planned between these. As shown in Fig. 3, the crankshaft box 1 is a trochoid type oil pump 15 which is driven from the crankshaft 5 through reduction gear sets 14, 14 '. The oil pump 15 is pumped from the oil concentration point at the bottom of the crankshaft box 1 and is discharged from the discharge port 15a. Therefore, the oil discharged from the discharge port 15a passes through the side wall of the crankshaft box 1. It faces the front oil passage 20, and rises through the upward oil groove 21 of the rear end surface of the cylinder block 2. Through the oil system facing the oil groove 21, the uppermost one screw pile 4 is completely inserted into the cylinder block 2 -8- (6) (6)! 2215〇3 and a series of screw inspection formed by the cylinder head 3. The hole 19 'flows into the oil hole 22 of the rocker shaft 10a of the valve mechanism 10, and is sprayed from the oil supply hole 23 to lubricate the rocker arm and the like. In addition, part of the oil flowing into the bolt hole 19 passes through the inclined oil passage 24 of the cylinder block 2 and rises through the oil groove 25 on the end face of the head cover 1 toward the front oil path of the upper wall of the head cover 1 2 6 moves and is ejected from the injection hole 28, and the valve mechanism 10 is lubricated from the upper part. In addition, the other part of the oil flowing into the groove 21 in the up-and-down direction of the rear end face of the cylinder block 2 is the rear-facing oil path of the crank journal supporting wall 1 b which is on the way to the right of the crank case 1 from the groove 21. 28, and is supplied to the lubrication around the crank shaft 5. Next, the structure of the crank shaft 5 will be described in detail with reference to Figs. 6 and 7. The crank shaft 5 is provided with a pair of crank journals 5j a, 5jb, which are supported by the left and right crank journal support walls 1 a, lb of the crank case 1 via the left and right ball bearings 6 a, 6 b, And a pair of crank arms 5wa, 5wb which are integrally formed at opposite ends of these crank journals 5ja, 5jb and extend outward in the radial direction. The front ends of these crank arms 5wa and 5wb are individually provided with connection holes 30 parallel to the crank journals 5 ja and 5 jb, and both ends of the crank pin 5p are pressed into these connection holes 30. Thus, the two cranks The arms 5 wa and 5 wb are connected to each other integrally by a crank pin 5 p. The crank pin 5p is press-fitted into the connection hole 30 in advance, and the large end portion 7a of the connecting rod 7 is fitted into the outer periphery thereof with the needle bearing 31 interposed therebetween. In addition, the crank pin 5p is provided with holes for weight reduction and oil supply in advance. -9- (7) 1221503 3 2. The center C 3 of the hole 32 is offset from the Y axis of the two centers C1 and C2 of the crank journal 5 ja, 5 jb and the crank pin 5p toward the front side of the revolution side R of the crank pin 5p, and The center C2 of 5p is arranged from the inverse crank journal 5j a, 5jb side of the X-axis orthogonal to γ, that is, offset from the crank journal 5 ja, 5 jb by a distance e ′. Then, on the line L passing through the center C 3 of the hole 32 and the center C 2 of the crank pin 5 p toward the thin meat portion 3 3 of the crank pin 5 p, a large end portion connecting the hole 3 2 to the connecting rod 7 is passed. Oil supply hole 34 on the inner peripheral surface of 7a. The hole 3 2 is opened at one end surface of the crank pin 5 p and a ring-shaped mounting recess 35 is formed on the outer side of the open side of the crank arm 5 wb so as to extend radially outward than the crank pin 5 p. In addition, the oil receiving and receiving plate 36 is riveted and fixed in the mounting recess 35. The oil receiving and paying plate 36 is annular and shaped, and is arranged so as to cover a part of the opening of the hole 32. On the other hand, the crank journal support 1 b having the above-mentioned rear oil passage 28 is formed with a small cylindrical protrusion 3 7 protruding toward the crank pin 5 p side and surrounding the oil receiving and payment plate 3 6. The inner peripheral surface of the bearing outer ring of the support roller bearing 6b of the support wall 1b is provided with an oil groove 38 in the axial direction that communicates the rearward oil passage to the inner peripheral side of the small cylindrical protrusion 37. Next, the effect of this embodiment will be described. During the operation of the engine E, the oil discharged from the oil pump 15 and passing through the rear oil passage 28 of the crank journal bearing wall 1 b is inserted into the oil receiving and paying plate 36 through the oil groove 38 of the axial direction. And 3 2 ′ moving from here to the crank pin 5 p is ejected from the oil supply hole 34 by the action of the centrifugal force, and lubricates the inner peripheral surface of the needle roller bearing 31 or the large end portion 7 a of the connecting rod 7. Curved shaft handle demon ✓ ΐ ,, straight to give way to the bead 28 of the dish wall tributary hole shaft-10- (8) (8) 1221503 However, the center C3 of the hole 32 of the crank pin 5p is as described above, From the front side of the revolution direction R of the crank pin 5 p passing through the two centers C1, C 2 of the crank journal 5 ja, 5 jb and the crank pin 5 p; and at the center C 2 of the crank pin 5 p from Y The crank journal 5 ja '5 jb of the X-axis orthogonal to the axis is disposed sideways, and the piston 8 reaches the top dead center. When an explosive load is applied from the piston 8 to the crank pin 5p through the connecting rod 7, the explosive load acts on the crank pin 5p. The position where the thinnest part of the crank pin 5 p deviates, and the thickness of the crank pin 5 p increases at the point where the burst load acts as the expansion stroke progresses. Therefore, the strength of the crank pin 5 p can be high. Improved durability. In addition, the center C 3 of the hole 3 2 is deviated from the X axis toward the inverse crank journal 5 ja, 5jb side, and an oil supply hole 34 is installed in the thin meat portion 33 of the crank pin 5p, and the center of gravity of the crank pin 5p is positioned. It is closer to the crank journal 5ja and 5jb than the center C2 of the crank pin 5p. Therefore, the moment of inertia of the center C 1 of the crank journal 5ja and 5jb related to the crank pin 5p is greater than the center of the crank pin 5p. The hole 32 of C2 and the hole of the same diameter are smaller, so it helps to improve the acceleration of the engine E. Moreover, since the rotation radius of the oil supply hole 34 to the center of the crank journals 5j a and 5jb is large, the centrifugal force can be effectively applied to the oil in the oil supply hole 34, and the large end portion 7a of the connecting rod 7 can be well performed. Lubrication of inner peripheral surface. In addition, the crank shaft 5 is a combination formed by pressing the crank pin 5p into the connecting holes of the opposite crank arms 5 wa and 5 wb. By adjusting the pressing position of the crank pin 5 p, the crank pin 5 p can be adjusted. The offset amount of the Y axis and the X axis of the center C 3 of the hole 3 2 or the phase of the oil supply hole 34 can be set freely, and the versatility can be improved. -11-1221503 〇) Next, the second embodiment of the present invention will be described with reference to FIGS. 8 and 9. The crank shaft 5 of the second embodiment is a crank journal 5ja, 5jb by forging, etc .; 5 wa, 5 wb and the crank pin 5p are integrally formed, and the large end portion 7a of the connecting rod 7 supported by the crank pin 5p via the metal bearing 3 1 ′ is divided into two parts. In the crank pin 5p, a hole 3 2 is provided in parallel with the center line thereof, and it is arranged on the X axis by an offset distance e from the Y axis toward the front side of the revolution direction R of the crank pin 5p. In addition, on the crank pin 5p, an oil supply hole 34 'communicating with the hole 32 to the inner peripheral surface of the large end portion 7a of the connecting rod 7 is passed through the crank pin 5p, and at this time, the oil supply hole 34 'It is arranged to be offset from the X axis toward the reverse crank journal 5ja and 5jb. The other configurations are the same as those of the previous embodiment. Therefore, in FIGS. 8 and 9, the same reference numerals are added to the corresponding parts of the previous embodiment, and descriptions thereof are omitted. According to this second embodiment, regardless of the presence or absence of the hole 3 2 of the crank pin 5 p, the meat of the crank pin 5 p at the point where the explosive load acts can be made sufficiently thick during the expansion stroke of the engine, and can be obtained The strength of the crank pin 5 p is higher, and its durability is improved. Moreover, even if the hole 3 2 is located on the X axis, the oil supply hole 3 4 is installed on the crank pin 5p because the oil supply hole 3 4 is offset from the X axis toward the reverse crank journal 5 ja, 5 jb. Therefore, in this situation, the crank pin The center of gravity of 5p is located closer to the crank journal 5ja, 5jb than the center C2 of the crank pin 5P 'therefore, the inertia moment of the center C 1 of the crank journal 5 ja and 5 jb becomes smaller' So it helps -12-(10) (10) 1221503 to improve the acceleration of engine E. Finally, a third embodiment of the present invention will be described with reference to FIG. 10. This third embodiment is a point where the crank pin 5p is disposed in a hole 32 parallel to its center line, and the distance e on the X-axis is shifted from the Y-axis toward the revolution direction R of the crank pin 5p. This hole is not different from the above-mentioned second embodiment, but the hole 32 is different in that the predetermined strength of the crank pin 5 p is secured and the hole 32 has a larger diameter than the hole 32 of the second embodiment. That is, a case where a hole 03 2 having the smallest meat thickness which can be subjected to the burst load to the crank pin 5p at the center C2 of the crank pin 5p is considered. While ensuring its minimum thickness, in order to form the above-mentioned offset hole 32 with a larger diameter than the center hole 032, the offset hole 32 is formed so that the circumference passes through the intersection of the X axis and the circumference of the center hole 032. form. The other structures are the same as those of the second embodiment, and therefore, in FIG. 10, the same reference numerals are added to the corresponding parts of the second embodiment, and the description is omitted. According to the third embodiment, the diameter of the offset hole 32 can be increased without reducing the strength of the crank pin 5 p, and the weight can be reduced. 'At this time, the crank journal 5ja, 5jb related to the crank pin 5p The inertia moment of the center C1 is also reduced, which helps to improve the acceleration of the engine E. The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the gist. [Effects of the Invention] According to the first feature of the present invention as described above, the crank journal supported by the crankshaft box is supported by -13- (11) (11) 1221503, and the radial direction from the end of the crank journal to the radial direction. It consists of a crank arm extending from the outside and a crank pin extending parallel to the crank journal from the front end of the crank arm to support the large end of the connecting rod. The crank pin is provided with a hole extending parallel to the center line. Among the crank shafts of the engine, the center of the hole is shifted from the Y axis passing through the crank journal and the two centers of the crank pin toward the front side of the revolution direction of the crank pin. Therefore, the expansion stroke of the engine is applied from the piston through the connecting rod. When the explosive load of the crank pin, the explosive load acts on the place deviating from the thinnest part of the crank pin, and because the meat thickness of the crank pin at the point of the explosive load increases as the expansion stroke progresses, the crank can be sought The strength of the pin is high and its durability is improved. In addition, through the above-mentioned offset arrangement of the hole, the hole can be made larger in diameter, and the crank pin is lighter, so that the inertia moment of the crank pin related to the crank journal is reduced, and it is helpful to obtain the acceleration of the engine. Promotion. According to the second feature of the present invention, in addition to the first feature, the above-mentioned hole is communicated with the discharge side of the oil pump, and at the same time, it is communicated with the large end portion of the connecting rod through an oil supply hole provided in the crank pin. The peripheral surface, so the above-mentioned hole can be used to lubricate the oil hole on the inner peripheral surface of the large end portion of the connecting rod. According to the third feature of the present invention, in addition to the first feature, the center of the hole is shifted from the X-axis orthogonal to the γ-axis toward the inverse crank journal side at the center of the crank pin, and the hole is communicated with It is on the discharge side of the oil pump and communicates with the inner peripheral surface of the large end of the connecting rod on the straight line passing through the center of the hole and the center of the crank pin through the oil supply hole passing through the thin meat portion of the crank pin. The center of gravity of the crank pin is located closer to the crank journal than the center of the crank pin. Therefore, it is possible to reduce the inertia moment of the center of the crank pin related to the crank journal -14- (12) (12) 1221503 and accelerate the engine. Sexual improvement. In addition, because the rotation radius from the oil supply hole to the center of the crank journal is large, the centrifugal force can be effectively applied to the oil in the oil supply hole, and the inner peripheral surface of the large end portion of the connecting rod can be well lubricated. . According to the fourth feature of the present invention, in addition to the third feature, the crank arm is integrally formed on the crank journal, the crank pin is press-fitted into a connection hole provided in the crank arm, and the press-fit is used. The position sets the position of the aforementioned hole and the oil supply hole. By adjusting the press-in position of the crank pin, φ can freely set the offset amount of the Y axis and the X axis of the center of the hole of the crank pin or the oil supply hole. The phase can improve the versatility. According to the fifth feature of the present invention, in addition to the first feature, the center of the hole is arranged on the X axis where the center of the crank pin intersects the Y axis. Regardless of the existence of the hole of the crank pin, the engine expands. In the stroke, the flesh of the crank pin at the point where the burst load acts can be sufficiently thickened, and the strength of the crank pin can be increased, and the durability can be further improved. φ According to the sixth feature of the present invention, in addition to the fifth feature, the hole is connected to the discharge side of the oil pump, and at the same time, it is inserted into the crank pin at a position deviated from the X axis toward the reverse crank journal side Oil supply hole-connected to the inner peripheral surface of the large end of the connecting rod, so even if the hole is located on the X axis, the center of gravity of the crank pin is closer to the crank journal than the center of the crank pin, so the crank The moment of inertia of the center of the crank journal pin is reduced, and the acceleration of the engine can be improved. -15- (13) (13) 1221503 [Brief Description of the Drawings] Fig. 1 is a longitudinal sectional view of a locomotive engine including a crankshaft according to a first embodiment of the present invention. Figure 2 is a sectional view taken along line 2-2 of Figure 1. Fig. 3 is a sectional view taken along line 3-3 of Fig. 2. Figure 4 is a sectional view taken along line 4-4 of Figure 3. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3. Figure 6 is an enlarged view of part 6 of Figure 1. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. Fig. 8 is a sectional view corresponding to Fig. 6 showing a second embodiment of the present invention. Fig. 9 is a sectional view taken along line 9-9 in Fig. 8. Fig. 10 is a sectional view corresponding to Fig. 9 showing a third embodiment of the present invention. [Illustration of drawing number] C 1 Center of crank journal C2 Center of crank pin C3 Center of hole of crank pin E Engine L Straight line R Direction of rotation of crank pin 1 Crank shaft box 5 Crank shaft -16- (14) 1221503 5ja 、 5jb crank journal 5p crank pin 5 wa, 5 wb crank arm 7 connecting rod 7 a large end 3 0 connecting hole 32 Λ o hole of crank pin thin part 34 of crank pin 34, 34 ”oil supply hole -17-