1224172 Π) 玖、發明說明 【發明所屬之技術領域】 本發明係關於防止OHC型內燃機的吸排氣閥傳達系統 凸輪鏈條之脫落的構造。 【先前技術】 在OHC型內燃機，係爲了將被配置在氣缸頭的吸排氣 閥以預定之時機驅動，作爲將曲柄軸的旋轉驅動力傳達至 吸排氣閥機構之凸輪軸的手段而使用有凸輪鏈條。凸輪鏈 條係被懸掛於嵌裝在曲柄軸之驅動鏈輪和嵌裝在凸輪軸的 從動鍵輪。 在利用凸輪鏈條之驅動鏈輪的引入側設置有凸輪鏈條 導軌，另一方，在從凸輪鏈條的驅動鏈輪所送出之側，設 置有凸輪緊鏈器，藉由拉緊器升降機來按壓在鏈條。藉此 可防止吸排氣閥傳達系統凸輪鏈條之鬆弛。該凸輪緊鏈器 ’係在構造上成爲能夠在基端部轉動。基端部係以栓銷成 能夠轉動地保持，經由大型墊圈形狀的基端部按壓構件而 在栓銷頭部之螺栓部以螺帽防止脫落而被保持（例如，參 照專利文獻1。） 另外，在凸輪鏈條捲掛的驅動鏈輪，爲了防止內燃機 裝配時之鏈條脫落，設置有凸輪鏈條脫落防止板，凸輪鏈 條脫落防止板係與上述凸輪緊鏈器按壓構件爲個別之構件 (例如，參照專利文獻2。）。 -4- (2) (2)12241721224172 Π) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a structure for preventing the cam chain of an intake and exhaust valve conveying system of an OHC internal combustion engine from falling off. [Prior Art] In the OHC type internal combustion engine, an intake and exhaust valve disposed on a cylinder head is driven at a predetermined timing, and is used as a means for transmitting a rotational driving force of a crank shaft to a camshaft of an intake and exhaust valve mechanism. With cam chain. The cam chain is suspended from a driving sprocket embedded in the crank shaft and a driven key wheel embedded in the cam shaft. A cam chain guide is provided on the lead-in side of the drive sprocket using the cam chain. On the other hand, a cam tensioner is provided on the side sent from the drive sprocket of the cam chain. The tensioner lifter is used to press on the chain. . This prevents slack in the cam chain of the suction and discharge valve transmission system. This cam chain tightener 'is structured to be rotatable at a base end portion. The base end portion is rotatably held by a pin, and is held by a large-washer-shaped base end portion pressing member, and the bolt portion of the head portion of the pin is prevented from falling off by a nut (for example, refer to Patent Document 1). In order to prevent the chain from falling off during the assembly of the internal combustion engine, a cam chain fall prevention plate is provided on the driving sprocket wound on the cam chain. The cam chain fall prevention plate is a separate component from the above-mentioned cam tightener pressing member (for example, see Patent document 2.). -4- (2) (2) 1224172
[專利文獻1 J 曰本實開昭60-3 25 〇1號公報（第1圖） [專利文獻2 ；] 日本特開2000-303906號公報（第6圖、第18圖、第22 圖）。 【發明內容】 [發明所欲解決之課題] 本發明，係做爲以1個構件兼作凸輪緊鏈器按壓構件 和凸輪鏈條脫落防止板的構成，以設法削減零件數，和減 少裝配作業，設法提高生產性。 [用來解決課題之手段及效果] 本發明係解決上述課題而開發完成，申請專利範圍第 1項之發明，係針對於讓曲柄軸在曲柄軸箱經由滾動軸承 而自由旋轉地軸支，並且朝嵌裝在該曲柄軸的吸排氣閥傳 達系統凸輪鏈條之驅動鏈輪的外周部接近而設置有前述凸 輪鏈條之脫落防止板的防止內燃機之凸輪鏈條脫落的構造 之中，前述凸輪鏈條脫落防止板，係與前述凸輪緊鏈器的 基端部按壓構件形成爲一體，而該凸輪緊鏈器的基端部被 支撐成可自由迴旋並且該凸輪緊鏈器的背面被拉緊器升降 機推壓而推壓前述凸輪鏈條爲其特徵。 本發明係因爲如此地構成，故能以1個零件對雙方之 目的有用，能夠削減零件數，裝配作業也因爲減少，故生 -5- (3) (3)1224172 產性提局。 【實施方式】 第1圖係將關於本發明的一實施形態之機車用0HC型 內燃機的重要部份之橫剖面從後方觀察之圖。圖中’該內 燃機的外殼，係由左曲柄軸箱1、右曲柄軸箱2、左曲柄軸 箱蓋3、右曲柄軸箱蓋4、氣缸體5、氣缸頭6、氣缸頭盡7 所構成。曲柄軸8係由左右的部份而組成，藉由曲柄銷9製 作成一體化。曲柄軸8，係在左曲柄軸箱1和右曲柄軸箱2 分別經由滾動軸承1 〇、1 1而製作成能夠旋轉地支承。在曲 柄銷9經由連桿12而連接有活塞13，該活塞在氣缸體5之中 進行上下運動。在氣缸頭6的下面形成有燃燒室1 4。在氣 缸頭6裝設有火星塞15，其前端面臨上述燃燒室I4。在氣 缸頭6和氣缸頭蓋7之間藉由凸輪作製作成讓吸排氣閥機構 的凸輪軸1 6能夠旋轉地支承。 在如上述所裝配之內燃機的左側部，設置有將從凸輪 軸1 6之左端部空間至左曲柄軸箱1的內部貫通之凸輪鏈條 室1 7。在曲柄軸8的左側部份嵌裝有驅動鏈輪1 8，在凸輪 軸1 6之左端部固定有從動鏈輪1 9，在該兩鏈輪，懸掛有凸 輪鏈條2 0。藉此，將曲柄軸8的旋轉驅動力傳達至凸輪軸 1 6，能夠將配置在氣缸頭6的吸排氣閥以預定之時機驅動 〇[Patent Document 1 J. Japanese Publication No. 60-3 25 〇1 (Figure 1) [Patent Document 2;] Japanese Patent Laid-Open No. 2000-303906 (Figures 6, 18, and 22) . [Summary of the Invention] [Problems to be Solved by the Invention] The present invention aims to reduce the number of parts and reduce the number of parts, as well as the number of parts and the assembly work. Improve productivity. [Means and effects to solve the problem] The present invention is developed to solve the above-mentioned problems. The invention in the first patent application scope is aimed at allowing the crankshaft to freely rotate on the crankshaft box via a rolling bearing, and to face the bearing. The intake and exhaust valve transmission system of the crankshaft is equipped with a structure in which the outer periphery of the driving sprocket of the cam chain is approached, and the cam chain drop-off prevention plate is provided to prevent the cam chain of the internal combustion engine from falling off. Is formed integrally with the base end pressing member of the aforementioned cam chain tensioner, and the base end portion of the cam chain tensioner is supported to be freely rotatable and the back of the cam chain tensioner is pushed by the tensioner elevator It is characterized by pushing the aforementioned cam chain. Because the present invention is structured as such, one part can be useful for both parties' purposes, the number of parts can be reduced, and assembly operations can be reduced because of this. -5- (3) (3) 1224172 Productivity improvement. [Embodiment] FIG. 1 is a view in which a cross section of an important part of an 0HC internal combustion engine for a locomotive according to an embodiment of the present invention is viewed from the rear. In the figure, the casing of the internal combustion engine is composed of left crank shaft box 1, right crank shaft box 2, left crank shaft box cover 3, right crank shaft box cover 4, cylinder block 5, cylinder head 6, and cylinder head 7 . The crank shaft 8 is composed of left and right parts, and is integrated by a crank pin 9. The crank shaft 8 is attached to the left crank shaft case 1 and the right crank shaft case 2 via rolling bearings 10 and 11 to be rotatably supported. A piston 13 is connected to the crank pin 9 via a connecting rod 12, and the piston moves up and down in the cylinder block 5. A combustion chamber 14 is formed under the cylinder head 6. The cylinder head 6 is provided with a spark plug 15 whose front end faces the aforementioned combustion chamber I4. A camshaft 16 between the cylinder head 6 and the cylinder head cover 7 is rotatably supported by a cam. On the left side of the internal combustion engine assembled as described above, a cam chain chamber 17 is provided which penetrates from the left end space of the cam shaft 16 to the inside of the left crankcase 1. A drive sprocket 18 is embedded in the left part of the crank shaft 8, a driven sprocket 19 is fixed to the left end of the cam shaft 16, and a cam chain 20 is suspended on the two sprocket wheels. Thereby, the rotational driving force of the crank shaft 8 is transmitted to the cam shaft 16, and the intake and exhaust valves arranged in the cylinder head 6 can be driven at a predetermined timing.
第2圖係通過上述內燃機的凸輪鍵條室之縱剖面圖。 圖的左方爲前方。曲柄軸8及驅動鏈輪1 8係朝圖的箭號A -6- (4) (4)1224172 的方向旋轉。經由凸輪鏈條2 0所驅動的從動鏈輪1 9及曲柄 軸1 6係朝箭號Β之方向使之旋轉。 沿著藉由驅動鏈輪1 8而被拉之側的凸輪鏈條20，設置 有引導該凸輪鏈條的樹脂製之凸輪鏈條導軌2 1，並且固定 在凸輪鏈條室1 7的周圍之固定部。凸輪鏈條導軌2 1的凸輪 鏈條滑動側之剖面，係製作成爲大致相當於凸輪鏈條20的 寬度之凹溝，凸輪鏈條20在其溝底滑動。 沿著藉由驅動鏈輪1 8而被推出之側的凸輪鏈條20，設 置有凸輪緊鏈器22。凸輪緊鏈器22係將其下端部之支持部 作爲中心而能夠轉動地支承。貫通氣缸體5而設置有拉緊 器升降機23，以突出在鏈條室1 7內部的其前端推壓凸輪緊 鏈器22，並且被推壓之凸輪緊鏈器22將凸輪鏈條20按壓， 而防止凸輪鏈條20之鬆弛。 凸輪緊鏈器22，係由鋼鐵系金屬所製作的支臂24，和 安裝在同支臂2 4之鏈條滑動側的以樹脂所成型之墊塊2 5所 構成。墊塊2 5的凸輪鏈條滑動部，係彎曲成型成凸輪鏈條 翹曲之形，並且其凸輪鏈條滑動側的剖面，係製作成大致 相當於凸輪鏈條的寬度之凹溝，凸輪鏈條20在其溝底滑動 〇 藉由拉緊器升降機23所按壓的凸輪緊鏈器22之下端的 基端部係成爲轉動中心之部份。第3圖係支臂24的基端部 之圖’將金屬的端部彎曲而形成有运狀部2 4 a。第4圖爲塾 塊2 5的基端部之圖，並且在端部形成有開孔部2 5 a。第5圖 係將支臂24和墊塊25組合的凸輪緊鏈器22之基端部的圖， -7- (5) (5)1224172 並且在基端部之中心被形成有貫通孔26。 在第2圖中，凸輪鏈條20係捲繞懸掛在驅動鏈輪1 8之 部份的外周側上，僅留下微小空隙而讓凸輪鏈條脫落防止 板28藉由2個螺栓29、30而安裝在左曲柄軸箱1。第6圖係 上述凸輪鏈條脫落防止板2 8之圖。該構件係金屬製板狀構 件，並且設置有用來插通上述螺栓2 9、3 0的螺栓插通孔 2 8 a、2 8 b，而且在前端部設置有栓銷插通孔2 8 c。在周圍 之一部份設置有與鏈條相對向的彎曲緣28d。 凸輪緊鏈器22及凸輪鏈條脫落防止板28的安裝，係製 作成如下。首先在左曲柄軸箱1立設固定有栓銷2 7，並且 在此裝設有凸輪緊鏈器22的基端部之貫通孔26，而且裝設 有凸輪鏈條脫落防止板2 8的端部之栓銷插通孔2 8 c。此時 ，凸輪鏈條脫落防止板28的彎曲緣28 d係捲繞懸掛在驅動 鏈輪1 8之凸輪鏈條20的外周上僅留下微小之空隙而相對向 。在此狀態下，凸輪鏈條脫落防止板2 8，係在螺栓插通孔 28a、28b插通有螺栓29、30，並且螺接、固定在左曲柄軸 箱1。藉此，凸輪緊鏈器22係在其基端部能夠轉動地保持 〇 安裝凸輪鏈條脫落防止板28的本來之目的，係爲了防 止在裝配內燃機時的凸輪鏈條脫落。在內燃機裝配之時， 係在安裝曲柄軸而裝配的曲柄軸箱內’將懸掛在驅動鏈輪 1 8之凸輪鏈條20，事先通過氣缸體5內拉出在外，將氣缸 頭6安裝後，懸掛在從動鏈輪1 9。在上述製程中係將須懸 掛在驅動鏈輪1 8之凸輪鏈條20通過氣缸體5而朝外拉出的 -8- (6) (6)1224172 作業製程之中，凸輪鏈條20容易從驅動鏈輪18脫落。一旦 脫落時就必須再度把凸輪鏈條重掛於驅動鏈輪1 8而很麻煩 ’對此一旦安裝凸輪鏈條脫落防止板時，因爲凸輪鏈條20 和凸輪脫落防止板28之彎曲緣28d的空隙很小，所以藉此 能防止凸輪鏈條2 0朝驅動鏈輪1 8之半徑方向脫落。 過去，雖然凸輪緊鏈器的基端部按壓構件，和凸輪鏈 條脫落防止板係個別的構件，但是在本實施形態因將凸輪 鏈條脫落防止板之一端部延長而作爲凸輪緊鏈器的基端部 按壓構件而利用，故能削減零件數和裝配工數，而提高生 產性。 【圖式簡單說明】 第1圖係將關於本發明的一實施形態之機車用OHC型 內燃機的主要部份之橫剖面從後方觀察之圖。 第2圖係通過上述內燃機的凸輪鏈條室之主要部份的 縱剖面圖，圖之左方爲前方。 第3圖係支臂的基端部之圖。 第4圖係墊塊的基端部之圖。 第5圖係將支臂和墊塊組合的凸輪緊鏈器之基端部之 圖。 第6圖係上述凸輪鏈條脫落防止板之圖。 [符號之說明] 1......左曲柄軸箱、2......右曲柄軸箱、3......左曲柄 (7) (7)1224172 軸箱蓋、4……右曲柄軸箱蓋、5……氣缸體、6……氣缸 頭、7......氣缸頭蓋、8......曲柄軸、9......曲柄銷、1 〇… …滾動軸承、1 1......滾動軸承、1 2......連桿、1 3......活塞 、14......燃燒室、15......火星塞、16......凸輪軸、17...... 凸輪鏈條室、1 8 ··•…驅動鏈輪、1 9......從動鏈輪、2 0...... 凸輪鏈條、2 1……凸輪鏈條導軌、2 2……凸輪緊鏈器、2 3 ......拉緊器升降機、24......支臂、24a......支臂基端部之 環狀部、25……墊塊、25a……墊塊基端部之開孔部、26 ……貫通孔、2 7……栓銷、2 8……凸輪鏈條脫落防止板、 2 8a......螺栓插穿孔、2 8 b......螺栓插穿孔、2 8 c......栓銷 插通孔、28d......彎曲緣、29......螺检、30......螺检。Fig. 2 is a longitudinal sectional view of a cam key chamber passing through the internal combustion engine. The left side of the figure is the front. The crank shaft 8 and the drive sprocket 18 are rotated in the direction of arrows A -6- (4) (4) 1224172 in the figure. The driven sprocket 19 and the crank shaft 16 driven by the cam chain 20 rotate in the direction of arrow B. A resin-made cam chain guide 21 for guiding the cam chain is provided along the cam chain 20 on the side pulled by the driving sprocket 18, and is fixed to a fixing portion around the cam chain chamber 17. The cross section of the cam chain sliding side of the cam chain guide 21 is formed as a groove having a width substantially equal to the width of the cam chain 20, and the cam chain 20 slides at the groove bottom. A cam chain tensioner 22 is provided along the cam chain 20 on the side pushed out by driving the sprocket 18. The cam chain tensioner 22 is rotatably supported with the support portion at the lower end as a center. A tensioner lifter 23 is provided through the cylinder block 5 to protrude the front end of the chain chamber 17 to press the cam chain tensioner 22, and the pressed cam chain tensioner 22 presses the cam chain 20 to prevent The slack of the cam chain 20. The cam tightener 22 is composed of a support arm 24 made of iron and steel metal, and a resin-made cushion block 25 mounted on the sliding side of the same support arm 24. The cam chain sliding part of the pad 25 is curved and formed into a cam chain warping shape, and the cross section of the cam chain sliding side is made into a groove approximately equal to the width of the cam chain, and the cam chain 20 is in the groove. Bottom slide. The base end of the lower end of the cam chain tensioner 22 pressed by the tensioner elevator 23 becomes a part of the rotation center. Fig. 3 is a view of the base end portion of the support arm 24 ', and a metal end portion is bent to form a transport portion 2 4a. Fig. 4 is a view of the base end portion of the sampan block 25, and an opening portion 2a is formed at the end portion. Fig. 5 is a view of the base end portion of the cam chain tensioner 22 in which the arm 24 and the pad 25 are combined. -7- (5) (5) 1224172 and a through hole 26 is formed in the center of the base end portion. In the second figure, the cam chain 20 is wound and hung on the outer peripheral side of a portion of the drive sprocket 18, leaving only a slight gap to allow the cam chain to fall off, and the prevention plate 28 is attached by two bolts 29 and 30. 1 on the left crank shaft box. Fig. 6 is a view of the cam chain fall-off prevention plate 28. This member is a metal plate-like member and is provided with bolt insertion holes 2 8 a and 2 8 b for inserting the bolts 29 and 30 described above, and a bolt insertion hole 2 8 c is provided at the front end portion. A curved edge 28d facing the chain is provided at a part of the periphery. The attachment of the cam chain tightener 22 and the cam chain drop prevention plate 28 is made as follows. First, a bolt 27 is fixed on the left crankcase 1 and a through-hole 26 at the base end of the cam chain tensioner 22 is installed. An end of the cam chain drop-off prevention plate 28 is also installed. The pin insertion hole 2 8 c. At this time, the curved edge 28 d of the cam chain fall-off prevention plate 28 is wound and hung on the outer periphery of the cam chain 20 of the drive sprocket 18, leaving only a slight gap and facing each other. In this state, the cam chain fall-off prevention plate 28 is bolted to the bolt insertion holes 28a and 28b, and bolts 29 and 30 are bolted to the left crank shaft case 1. Thereby, the cam chain tensioner 22 is rotatably held at its base end. The original purpose of attaching the cam chain drop prevention plate 28 is to prevent the cam chain from falling off when the internal combustion engine is assembled. When the internal combustion engine is assembled, it is mounted in a crankshaft box assembled with a crankshaft, and will be suspended from the cam chain 20 of the driving sprocket 18, which is pulled out through the cylinder block 5 in advance, and after the cylinder head 6 is installed, the suspension is suspended. Under driven sprocket 1 9. In the above process, the cam chain 20, which must be suspended from the driving sprocket 18, is pulled out through the cylinder block -8- (6) (6) 1224172. During the manufacturing process, the cam chain 20 is easily removed from the drive chain. The wheel 18 comes off. Once detached, the cam chain must be re-hanged on the drive sprocket 18 again, which is troublesome. Once the cam chain detachment prevention plate is installed, the gap between the cam chain 20 and the cam edge 28d of the cam detachment prevention plate 28 is very small. Therefore, the cam chain 20 can be prevented from falling off in the radial direction of the driving sprocket 18 by this. In the past, although the base end pressing member of the cam chain tightener and the cam chain drop prevention plate are separate members, in this embodiment, the base end of the cam chain tightener is used as one of the ends of the cam chain drop prevention plate to extend. It is possible to reduce the number of parts and the number of assemblers and improve productivity by using the component by pressing the component. [Brief Description of Drawings] FIG. 1 is a view in which a cross section of a main part of an OHC-type internal combustion engine for a locomotive according to an embodiment of the present invention is viewed from the rear. Fig. 2 is a longitudinal sectional view of the main part of the cam chain chamber passing through the internal combustion engine, and the left side of the figure is forward. Fig. 3 is a diagram of the base end portion of the arm. Figure 4 is a diagram of the base end portion of the pad. Fig. 5 is a diagram of a base end portion of a cam tensioner in which a support arm and a pad are combined. Fig. 6 is a view of the cam chain drop-off preventing plate. [Explanation of Symbols] 1 ... left crank axle box, 2 ... right crank axle box, 3 ... left crank (7) (7) 1224172 axle box cover, 4 ... right crankshaft box cover, 5 ... cylinder block, 6 ... cylinder head, 7 ... cylinder head cover, 8 ... crank shaft, 9 ... crank pin, 1 〇…… rolling bearings, 1 1 ... rolling bearings, 1 2 ... connecting rods, 1 3 ... pistons, 14 ... combustion chambers, 15 .. .... Martian plug, 16 ... camshaft, 17 ... cam chain chamber, 1 8 ··· ... drive sprocket, 1 9 ... driven sprocket , 2 0 ... cam chain, 2 1 ... cam chain guide, 2 2 ... cam chain tensioner, 2 3 ... tensioner elevator, 24 ... support Arm, 24a ... annular part of the base of the arm, 25 ... pad, 25a ... opening of the base of the pad, 26 ... through hole, 2 7 ... bolt , 2 8 ... Cam chain drop prevention plate, 2 8a ... Bolt insertion hole, 2 8 b ... Bolt insertion hole, 2 8 c ... Bolt insertion hole , 28d ... bending edge, 29 ... screw inspection, 30 ... screw inspection.