200409859 (1) 玖、發明說明 【發明所屬之技術領域】 本發明是關於搭載於機車的氣冷式內燃機的冷卻風通 路。 【先前技術】 以往的氣冷式內燃機，是如以下的構造。在該內燃機 ，在氣缸頭的前部，是並排設置有：兩個排氣口與對應的 兩個排氣閥，在後部則並排設置有：兩個進氣口與對應的 兩個進氣閥，在上述四個閥所包圍的位置設置有火星塞， 在氣缸頭與氣缸頭外殼之間，設置有朝向左右方向的凸輪 軸，設置有：通過兩個排氣閥之間、及兩個進氣閥之間， 朝前後方向貫穿氣缸頭的冷卻風通路，且設置有連通於上 述前後方向冷卻風通路的橫方向冷卻風通路（例如，參照 專利文獻1)。在該例子中，在周圍具有間隙且包圍著火 星塞的主體部的火星塞裝卸孔是被設置在氣缸頭，該火星 塞裝卸孔也連通於上述前後方向冷卻風通路。 在該內燃機被搭載於機車的狀態，當機車行駛時，空 氣會從前後方向冷卻風通路的前方開口流入，其中一部分 的空氣會從上述火星塞裝卸孔通往內燃機的上部外側，另 一部分會從橫方向冷卻風通路通往內燃機的側部外側，其 餘的空氣會從前後方向冷卻風通路的後方開口通往後方。 在該空氣流通的過程，氣缸頭與火星塞會被冷卻。 (2) (2)200409859 〔專利文獻1〕 日本特公昭62— 43050號公報（第2圖、第3圖）。 【發明內容】 〔發明欲解決的課題〕 在傳統技術中，冷卻風通路的氣冷的效果並不夠。而 且不容易進行火星塞的裝卸。本發明，希望提昇冷卻風通 路的氣冷效果，並且將火星塞設置在容易裝卸的位置，而 可進行有效的氣冷。 〔用以解決課題的手段及效果〕 本發明是用來解決上述的課題，第1發明，是在燃燒 室的上部設置閥門機構，在上述燃燒室與上述閥門機構之 間，沿著排氣口與進氣口設置前後方向的冷卻風通路的氣 冷式內燃機，在上述排氣口與進氣口之間，設置連通於上 述前後方向的冷卻風通路的橫方向冷卻風通路，在同橫方 向冷卻風通路設置火星塞，並且設置有從上述前後方向冷 卻風通路朝向上述橫方向冷卻風通路彎曲的冷卻用散熱片 〇 本發明的這種構造，由於是在燃燒室上方的冷卻風通 路之中設置冷卻用散熱片，所以可以有效地將燃燒室周邊 冷卻。在橫方向冷卻風通路內設置火星塞，冷卻用散熱片 是彎曲成將冷卻風導引向同火星塞的方向’所以可以防止 火星塞的過熱。 -6- (3) 200409859 \ 第2發明，是針對第1發明的氣冷式內燃機’使上述 排氣口中心線傾斜於內燃機前後方向，以加寬上述前後方 向冷卻風通路的前方開口。 本發明的這種構造，前方開口的開口面積會變大’可 以將大量的空氣導入至冷卻風通路，所以可以提高空氣流 所造成的氣冷的效果。200409859 (1) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a cooling air passage of an air-cooled internal combustion engine mounted on a locomotive. [Prior Art] A conventional air-cooled internal combustion engine has the following structure. In this internal combustion engine, two exhaust ports and two corresponding exhaust valves are arranged side by side in the front part of the cylinder head, and two intake ports and two corresponding intake valves are arranged side by side in the rear part. A spark plug is provided at a position surrounded by the four valves, and a cam shaft facing left and right is provided between the cylinder head and the cylinder head housing, and is provided between the two exhaust valves and two inlet valves. Between the air valves, a cooling air passage that passes through the cylinder head in the front-rear direction is provided, and a lateral cooling air passage that communicates with the cooling air passage in the front-rear direction is provided (for example, refer to Patent Document 1). In this example, a spark plug attachment hole is provided in the cylinder head with a clearance around the main body of the spark plug, and the spark plug attachment hole also communicates with the cooling air passage in the front-rear direction. In the state where the internal combustion engine is mounted on a locomotive, when the locomotive is traveling, air flows in from the front opening of the cooling air passage in the front-rear direction, and a part of the air passes from the above-mentioned spark plug loading and unloading hole to the upper side of the internal combustion engine, and the other part passes The cooling air passage in the horizontal direction leads to the outside of the side of the internal combustion engine, and the remaining air flows from the rear opening of the cooling air passage in the forward and backward direction to the rear. During this air circulation, the cylinder head and the spark plug will be cooled. (2) (2) 200409859 [Patent Document 1] Japanese Patent Publication No. 62-43050 (Figure 2 and Figure 3). [Summary of the Invention] [Problems to be Solved by the Invention] In the conventional technology, the effect of air cooling of the cooling air passage is insufficient. And it is not easy to load and unload the spark plug. In the present invention, it is desired to improve the air-cooling effect of the cooling air passage, and to set the spark plug at a position where it can be easily attached and detached, so that effective air-cooling can be performed. [Means and Effects for Solving the Problems] The present invention is to solve the above-mentioned problems. The first invention is to provide a valve mechanism on the upper part of the combustion chamber, and between the combustion chamber and the valve mechanism, along the exhaust port An air-cooled internal combustion engine provided with a cooling air passage in the front-rear direction with the air inlet. A horizontal cooling air passage in the lateral direction communicating with the cooling air passage in the front-rear direction is provided between the exhaust port and the air inlet. The cooling air passage is provided with a spark plug, and a cooling fin which is curved from the front-rear direction cooling air passage to the lateral cooling air passage is provided. The structure of the present invention is in the cooling air passage above the combustion chamber. Since cooling fins are provided, the periphery of the combustion chamber can be effectively cooled. A spark plug is provided in the cooling air passage in the horizontal direction, and the cooling fins are bent to guide the cooling air in the same direction as the spark plug ', so that the spark plug can be prevented from overheating. -6- (3) 200409859 \ The second invention is directed to the air-cooled internal combustion engine of the first invention. The centerline of the exhaust port is inclined to the front-back direction of the internal combustion engine to widen the front-rear opening to the front of the cooling air passage. According to the structure of the present invention, the opening area of the front opening becomes large, and a large amount of air can be introduced into the cooling air passage, so that the effect of air cooling by the air flow can be improved.
【實施方式】[Embodiment]
第1圖是本發明的一實施方式的氣冷式內燃機1的主 要部分縱剖面圖，是顯示頭閥式凸輪軸型單氣缸內燃機的 上部。在圖中箭頭F是指出前方。在圖中，內燃機1的主 要部分的外殼’是由：氣缸體2、氣缸頭3、氣缸頭外殼 4所構成。在氣缸體2中，活塞5進行上下運動，在氣缸 頭3的下面側形成有燃燒室6 °在氣缸頭3形成了聯繋於 燃燒室6的排氣口 7與排氣口 9。在排氣口 7的內側端設 置有用來開閉該通路的排氣閥8。在排氣口 7的外側端是 連接著省略圖示的排氣管。在進氣口 9的內側端是設置有 用來開閉其通路的進氣閥1 0。在進氣口 9的外側端是連 接著省略圖示的化油器。 排氣閥8是讓其軸部8 a前傾而設置在靠近氣缸頭3 前側，在軸部8 a的上部突出部安裝有將排氣閥8朝向關 閉方向彈壓的閥彈簧1 1。進氣閥1 〇是讓其軸部1 〇a前傾 而設置在靠近氣缸頭3後側，在軸部1 〇a的上部突出部安 裝有將進氣閥1 〇朝向關閉方向彈壓的閥彈簧1 2。 (4) 200409859Fig. 1 is a longitudinal sectional view of a main part of an air-cooled internal combustion engine 1 according to an embodiment of the present invention, and shows an upper portion of a head-valve camshaft-type single-cylinder internal combustion engine. Arrow F in the figure indicates the front. In the figure, a main casing of the internal combustion engine 1 is composed of a cylinder block 2, a cylinder head 3, and a cylinder head casing 4. As shown in FIG. In the cylinder block 2, the piston 5 moves up and down, a combustion chamber 6 is formed on the lower side of the cylinder head 3, and an exhaust port 7 and an exhaust port 9 connected to the combustion chamber 6 are formed in the cylinder head 3. An exhaust valve 8 for opening and closing the passage is provided at the inner end of the exhaust port 7. An exhaust pipe (not shown) is connected to the outer end of the exhaust port 7. An intake valve 10 for opening and closing the passage is provided at the inner end of the intake port 9. The outer end of the air inlet 9 is a carburetor which is not shown in the drawing. The exhaust valve 8 is provided with its shaft portion 8a leaning forward and close to the front side of the cylinder head 3. A valve spring 11 is mounted on the upper protruding portion of the shaft portion 8a to urge the exhaust valve 8 in the closing direction. The intake valve 1 〇 is provided with the shaft portion 10 a leaning forward and close to the rear side of the cylinder head 3, and a valve spring that urges the intake valve 1 〇 toward the closing direction is attached to an upper protruding portion of the shaft portion 10 a. 1 2. (4) 200409859
藉由氣缸頭3與氣缸頭外殼4形成了閥門室1 3，這 裡收容有用來將上述排氣閥8與進氣閥1 〇開閉的閥門機 構。在以排氣閥8與進氣閥1 0所形成的V字型的空間， 是將相對於內燃機1的前後方向垂直相交的左右方向的凸 輪軸1 4可旋轉地支承在氣缸頭3與氣缸頭外殻4的配合 面之間。在該凸輪軸1 4是形成有：用來將排氣閥8開閉 驅動的排氣用凸輪1 5、與用來將進氣閥1 〇開閉驅動的進 氣用凸輪1 6。A valve chamber 13 is formed by the cylinder head 3 and the cylinder head housing 4, and a valve mechanism for opening and closing the exhaust valve 8 and the intake valve 10 is housed therein. In the V-shaped space formed by the exhaust valve 8 and the intake valve 10, a camshaft 14 in the left-right direction which intersects the front-back direction of the internal combustion engine 1 is rotatably supported by the cylinder head 3 and the cylinder. Between the mating surfaces of the head shell 4. The camshaft 14 includes an exhaust cam 15 for driving the exhaust valve 8 to open and close, and an intake cam 16 for driving the intake valve 10 to open and close.
在排氣閥8的上方是將排氣用搖臂1 7可擺動地支承 在排氣用搖臂軸1 8，其中一端是經由推桿1 9而連接於排 氣閥的軸部8 a的上端，另一端則是經由被支承在滾子軸 2 0的排氣用滾子2 1而連接於排氣用凸輪1 5。在進氣閥 10的上方是將進氣用搖臂22可擺動地支承在進氣用搖臂 軸23，其中一端是經由推桿24而連接於進氣閥的軸部 l〇a的上端，另一端則是經由被支承在滾子軸25的進氣 用滾子26而連接於進氣用凸輪16。 第2圖則是從後方來看上述內燃機1的主要部分的橫 剖面的視圖。在圖中，在氣缸頭3，在其右側部安裝著火 星塞27，其前端的電極27a是突出於燃燒室6內。凸輪 軸1 4的其中一端是突出於鏈條室2 8內，在其突出端固定 著從動鏈輪29。在曲軸固定著驅動鏈輪（沒有圖示）’ 在鏈條室2 8中，在上述驅動鏈輪與從動鏈輪2 9之間繞掛 著凸輪鏈條3 0。當曲軸旋轉時，會經由凸輪鏈條3 0來旋 轉驅動凸輪軸1 4。 (5) (5)200409859 第3圖是第2圖的III — III剖面圖，是表示上述內燃 機的水平剖面。在圖中，是顯示將火星塞27卸下，露出 火星塞安裝部3 1的狀態。箭頭F是指向前方，沿著鏈條 室28的周壁28a的氣缸頭中央側，形成有朝前後方向貫 穿於氣缸頭的前後方向冷卻風通路3 2。鏈條室周壁2 8 a 與排氣口周壁7a所夾著的空間是前方開口 3 3，鏈條室周 壁28a與進氣口周壁9a所夾著的空間是後方開口 34。並 且’形成了 ：連通於上述前後方向冷卻風通路32，通過 排氣口周壁7a與進氣口周壁9a之間，通往內燃機的側邊 的橫方向冷卻風通路3 5。火星塞3 1的兩側的外側是側邊 開口 3 6。如圖所示，是使排氣口 7的中心線a相對於內 燃機的前後方向線B朝向加寬前方開口 3 3的方向傾斜角 度^ ’以加大前方開口 3 3的開口面積，將大量的空氣導 入至冷卻風通路。 在前後方向冷卻風通路3 2與橫方向冷卻風通路3 5的 連接部、以及橫方向冷卻風通路3 5中，形成有三片冷卻 用散熱片。是前散熱片3 7，中散熱片3 8，後散熱片3 9。 圖面的中散熱片3 8，後散熱片3 9的陰影部分，是爲了補 強而增厚的背厚部，其頂部是聯繋到冷卻風通路的頂部。 第4圖是從斜後上方來看上述冷卻用散熱片的立體圖 。中散熱片3 8、後散熱片3 9的頂部的陰影部分，是聯繫 到冷卻風通路的頂部的背厚部3 8 a、3 9 a的頂部的剖面。 在第1圖，在橫方向冷卻風通路35內描繪有三枚散熱片 的縱剖面。在第2圖，是以從內燃機後方來看設置在冷卻 -9 - (6) (6)200409859 風通路的上述三枚散熱片的方式描繪。 本實施方式的氣冷式內燃機的構造如以上的方式構成 。搭載著該內燃機的機車在行駛時，會產生行駛氣流，該 行駛氣流會從前後方向冷卻風通路3 2的前方開口 3 3流入 ，氣流的一部分會藉由三片散熱片的導引作用，經過橫方 向冷卻風通路3 5，通過火星塞2 7兩側，從側邊開口 3 6 流出。另一部份的氣流會通往三片散熱片間，從前後方向 冷卻風通路3 2的後方開口 3 4流出。 在車輛行駛中，藉由行駛氣流，來冷卻面向前後方向 冷卻風通路3 2與橫方向冷卻風通路3 5的氣缸頭的外壁面 。特別是，燃燒室6的高溫，會經由燃燒室頂部外殼40 (第2圖）傳達到前、中、後的散熱片3 7、3 8、3 9，藉 由前後方向冷卻風及橫方向冷卻風來進行冷卻。藉由這些 冷卻作用，防止氣缸頭的過熱，來防止氣缸頭周圍的密封 惡化的情形。在火星塞3 0的電極3 0 a所產生的高溫，會 傳達到火星塞3 0的外側露出部，藉由上述的橫方向冷卻 風加以冷卻’防止火星塞的過熱所導致的惡化，延長火星 塞的使用期限。而本發明的火星塞是傾斜設置在橫方向冷 卻風通路中’所以容易從內燃機的側部進行裝卸，而讓維 修性提昇。 如第3圖所示，是使排氣口 7的中心線a相對於內 燃機的前後方向線B朝向加寬前方開口 3 3的方向傾斜角 度α ’以加大前方開口 3 3的開口面積，將大量的空氣導 入至冷卻風通路，可以提高行駛氣流的氣冷效果。 -10- (7) (7)200409859 【圖式簡單說明】 第1圖是本發明的—實施方式的氣冷式內燃機的主要 部分縱剖面圖。 第2圖帛«έ帛方來看上_ m然機的主帛部分的橫剖面 的視圖。 桌3圖疋上述內燃機的氣缸頭的水平剖面圖（第2圖 的III— III剖面）。 第4圖是從斜後上方來看冷卻用散熱片的立體圖。 〔圖號說明〕 1 :氣冷式內燃機 2 :氣缸體 3 :氣缸頭 4 :氣缸頭外殼 5 :活塞 6 :燃燒室 7 :排氣口 7 a :排氣口周壁 8 :排氣閥 9 :進氣閥 9a :進氣口周壁 I 0 :進氣閥 II :閥彈簧 -11 - (8) (8)200409859 1 2 :閥彈簧 13 :閥門室 1 4 :凸輪軸 1 5 :排氣用凸輪 1 6 =進氣用凸輪 1 7 :排氣用搖臂 1 8 :排氣用搖臂軸 1 9 :推桿 20 :滾子軸 2 1 :排氣用滾子 22 :進氣用搖臂 23 :進氣搖臂軸 2 4 :推桿 25 :滾子軸 26 :進氣用滾子 27 :火星塞 2 7 a :電極 2 8 :鏈條室 2 8 a :鏈條室周壁 29 :從動鏈輪 3 〇 :凸輪鏈條 3 1 :火星塞安裝部 32 :前後方向冷卻風通路 3 3 :前方開口 -12- (9)200409859Above the exhaust valve 8, an exhaust rocker arm 17 is swingably supported on the exhaust rocker shaft 18, and one end thereof is connected to a shaft portion 8a of the exhaust valve via a push rod 19 The upper end and the other end are connected to an exhaust cam 15 via an exhaust roller 21 supported on a roller shaft 20. Above the intake valve 10, an intake rocker arm 22 is swingably supported on the intake rocker shaft 23, and one end thereof is an upper end of a shaft portion 10a connected to the intake valve via a push rod 24. The other end is connected to the intake cam 16 via an intake roller 26 supported by a roller shaft 25. Fig. 2 is a cross-sectional view of the main part of the internal combustion engine 1 as viewed from the rear. In the figure, a spark plug 27 is attached to the right side of the cylinder head 3, and an electrode 27a at the front end thereof protrudes into the combustion chamber 6. One end of the cam shaft 14 is projected into the chain chamber 28, and a driven sprocket 29 is fixed to the projected end. A driving sprocket (not shown) is fixed to the crankshaft. In the chain chamber 28, a cam chain 30 is wound between the driving sprocket and the driven sprocket 29. When the crankshaft rotates, the camshaft 14 is driven to rotate via the cam chain 30. (5) (5) 200409859 Fig. 3 is a sectional view taken along the line III-III in Fig. 2 and is a horizontal section showing the internal combustion engine. The figure shows a state where the spark plug 27 is removed and the spark plug mounting portion 31 is exposed. An arrow F is a front-to-back cooling air passage 32 that passes through the cylinder head in the front-back direction along the center side of the cylinder head of the peripheral wall 28a of the chain chamber 28. The space sandwiched between the chain chamber peripheral wall 2 8a and the exhaust port peripheral wall 7a is a front opening 33, and the space sandwiched between the chain chamber peripheral wall 28a and the intake port peripheral wall 9a is a rear opening 34. And, a lateral cooling air passage 35, which communicates with the cooling air passage 32 in the front-rear direction and passes between the exhaust port peripheral wall 7a and the intake port peripheral wall 9a to the side of the internal combustion engine, is formed. The outer sides of the Mars Plug 3 1 are side openings 3 6. As shown in the figure, the center line a of the exhaust port 7 is inclined toward the direction in which the front opening 33 is widened relative to the front-back direction line B of the internal combustion engine to increase the opening area of the front opening 33, and a large number of Air is introduced into the cooling air passage. Three cooling fins are formed in a connection portion between the front-back cooling air passage 32 and the horizontal cooling air passage 35, and the horizontal cooling air passage 35. It is the front heat sink 3 7, the middle heat sink 3 8 and the rear heat sink 3 9. The shaded parts of the middle fins 38 and the rear fins 39 in the figure are thick portions of the back thickened for reinforcement, and the top is connected to the top of the cooling air passage. Fig. 4 is a perspective view of the cooling fins as viewed obliquely from the rear and above. The shaded portions on the tops of the middle fins 38 and the rear fins 39 are cross-sections of the tops of the back thick portions 3 8 a and 3 9 a that are connected to the tops of the cooling air passages. In Fig. 1, a longitudinal section of three cooling fins is drawn in the cooling air passage 35 in the horizontal direction. In FIG. 2, the three fins provided in the cooling -9-(6) (6) 200409859 air passage are viewed from the rear of the internal combustion engine. The structure of the air-cooled internal combustion engine of the present embodiment is configured as described above. When a locomotive equipped with the internal combustion engine is traveling, a driving airflow is generated, and the driving airflow flows in from the front opening 3 3 of the cooling air passage 32 in the front-to-rear direction. A part of the airflow is guided by three fins and passes through. The cooling air passage 35 in the horizontal direction passes through the two sides of the spark plug 2 7 and flows out from the side opening 3 6. The other part of the airflow will lead to the space between the three fins and flow out from the rear opening 3 4 of the cooling air passage 3 2 in the front-rear direction. During the running of the vehicle, the outer wall surfaces of the cylinder heads facing the front and rear cooling air passages 32 and the lateral cooling air passages 35 are cooled by the traveling airflow. In particular, the high temperature of the combustion chamber 6 is transmitted to the front, middle, and rear fins 37, 38, 39 through the combustion chamber top case 40 (Figure 2), and is cooled by front-to-back cooling air and lateral cooling. The wind comes to cool. These cooling effects prevent the cylinder head from overheating and prevent deterioration of the seal around the cylinder head. The high temperature generated at the electrode 3 0 a of the Mars plug 30 will be transmitted to the exposed part of the outside of the Mars plug 30 and cooled by the above-mentioned lateral cooling air to prevent deterioration due to overheating of the Mars plug and prolong Mars. The life of the plug. However, the spark plug of the present invention is inclinedly disposed in the cooling air passage in the lateral direction, so it is easy to attach and detach from the side of the internal combustion engine, thereby improving the maintainability. As shown in FIG. 3, the center line a of the exhaust port 7 is inclined toward the direction in which the front opening 33 is widened with respect to the front-back direction line B of the internal combustion engine by an angle α ′ to increase the opening area of the front opening 33. A large amount of air is introduced into the cooling air passage, which can improve the air cooling effect of the traveling airflow. -10- (7) (7) 200409859 [Brief description of the drawings] Fig. 1 is a longitudinal sectional view of a main part of an air-cooled internal combustion engine according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the main part of the machine when viewed from above. Table 3 shows a horizontal sectional view of the cylinder head of the internal combustion engine (section III-III in FIG. 2). FIG. 4 is a perspective view of the cooling fins as viewed obliquely from the rear and upward. [Illustration of drawing number] 1: Air-cooled internal combustion engine 2: Cylinder block 3: Cylinder head 4: Cylinder head housing 5: Piston 6: Combustion chamber 7: Exhaust port 7a: Exhaust port peripheral wall 8: Exhaust valve 9: Intake valve 9a: Intake port peripheral wall I 0: Intake valve II: Valve spring -11-(8) (8) 200409859 1 2: Valve spring 13: Valve chamber 1 4: Camshaft 1 5: Exhaust cam 1 6 = Intake cam 1 7: Exhaust rocker 1 8: Exhaust rocker shaft 1 9: Push rod 20: Roller shaft 2 1: Exhaust roller 22: Intake rocker 23 : Inlet rocker shaft 2 4: Push rod 25: Roller shaft 26: Intake roller 27: Mars plug 2 7 a: Electrode 2 8: Chain chamber 2 8 a: Chain chamber peripheral wall 29: Driven sprocket 3 〇: Cam chain 3 1: Mars plug mounting portion 32: Front and rear cooling air passage 3 3: Front opening -12- (9) 200409859
3 4 :後方開口 3 5 :橫方向冷卻風通路 3 6 :側邊開口 3 7 :前散熱片 3 8 :中散熱片 3 8 a :中散熱片的背厚部 3 9 :後散熱片 3 9a :後散熱片的背厚部 40 :燃燒室頂部外殻3 4: rear opening 3 5: lateral cooling air passage 3 6: side opening 3 7: front fins 3 8: middle fins 3 8 a: back thick portion of middle fins 3 9: rear fins 3 9a : Back thick part of rear fins 40: Combustion chamber top case
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