M392874 五、新型說明： 【新型所屬之技術領域】 本創作係關於一種引擎，尤指一種適用於強制氣冷引 .擎之改良結構。 【先前技術】 機車引擎冷卻系統之目的是在避免引擎過執而損 壞’或避免工作效率降低。機車冷卻系統可概分為空冷系 統、與水冷系統，前者是藉由空氣在引擎周圍流動以帶走 熱量’後者是㈣水與冷卻觀合而成的抗;㈣在引擎水 套内流動以帶走熱量。 參考圖1，為胃知空冷引擎平面圖。冑中示出一機車 所配備之空冷引擎，其在汽缸體丨與汽缸頭2上會成型出複 數散熱鰭片，並有一導風罩3罩蓋在汽缸體碘汽缸頭2周 圍，用以導引由一風扇4吸引進入之氣流集中地往汽缸體i 與汽缸頭2流動吹過。 圖2與圖3分別為兩種不同之習知空冷引擎汽缸頭立 體圖。圖2中，汽缸頭2於進氣側外表面突出形成有複數進 虱側散熱鰭片2a、於排氣側外表面突出形成有複數排氣側 1片2b相鄰進氣側散熱錯片2a間彼此間隔排列而形 成複數第—冷卻間隙2c，相鄰排氣側散熱韓片2b間亦同樣 彼此間隔排列而形成複數第二冷卻間隙2 d。本文所稱進氣 係指W擎中靠近進氣閥門之-側’而排氣側指靠近排氣 伐門之一側，二者是引擎相對之兩側。分別鄰接進氣側外 3 M392874 表面與排氣側外表面的是點火側外表面。 上述兩種散熱鰭片皆延伸至點火側外表面，複數進氣 側散熱鰭片2a與複數排氣側散熱鰭片2b於點火側外表面並 不相連’甚且一者之間界定出一火星塞冷卻道5。特別的 是’此種習知汽缸頭結構中，進氣側散熱鰭片2a與排氣側 散熱鰭片2b於點火側外表面之部份皆鄰接有一擋壁6,7。也 由於擋壁6,7之存在’火星塞冷卻道5皆不與第一冷卻間隙 2c、第二冷卻間隙2d連通，如此可加強對火星塞之冷卻作 用。 圖3中引擎汽缸頭結構與圖2之差異處在於，進氣側散 熱鰭片8a與排氣侧散熱鰭片8b於點火侧外表面之部份皆未 鄰接有擋壁，因此火星塞冷卻道9皆與第一冷卻間隙8c、第 二冷卻間隙8d連通’如此不僅使冷卻空氣流至火星塞冷卻 道9 ’亦可分散流入第一冷卻間隙8 c、及第二冷卻間隙8 d 而加大冷卻汽缸頭2之面積。 然而，實務上當引擎運轉一定時間之後，排氣側溫度 會明顯較其它處更高，而排氣閥門座若溫度過高會造成材 質劣化，進而導致閥門關閉不完全、漏氣之現象。因此有 必要修正習知引擎汽缸頭冷卻結構之不良設計，加強排氣 側冷卻作用，使引擎整體溫度更為均勻。 【新型内容】 本創作之引擎改良結構包括一汽缸頭、一導風罩、複 數進氣側政熱結片、及複數排氡側散熱韓片。上述汽缸頭 M392874 包括有-進氣側外表面、一點火側外表面、及一排氣側外 表面，點火侧外表面分別鄰接於進氣側外表面與該氣側外 表面。導風罩罩蓋於汽缸頭周圍。 上述進氣側散熱鰭片係自進氣側外表面突伸出，並延 伸至點火側外表面，彼此間隔排列而形成複數第一冷卻間 隙。上述排氣側散熱鰭片係自該排氣側外表面突伸出並 延伸至點火側外表面，彼此間隔排列而形成複數第二冷卻 間隙，其中於點火側外表面上，複數進氣側散熱鰭片與複 數排氣側散熱鰭片之間界定出一火星塞冷卻道。 本創作特色在於，上述第二冷卻間隙與火星塞冷卻道 連通，且進氣側散熱鰭片於點火側外表面之部份鄰接有一 擋壁，擋壁隔絕火星塞冷卻道與第一冷卻間隙之連通。 藉由上述改良結構，冷卻空氣流至火星塞冷卻道後會 擋壁隔絕而不致流動到第一冷卻間隙，亦即減少進氣側散 熱鰭片冷卻作用之配比，同時又兼顧排氣側散熱鰭片之冷 卻。因此，引擎整體溫度分佈較習知結構更趨均勻，減少 閥門座損壞情形。 上述擋壁可為與汽缸頭一體成型者'亦可為與導風罩 一體成型者。汽缸頭可更包括二進氣閥門座、及二排氣間 門座。 引擎改良結構可更包括有一汽缸體係結合於汽虹 頭，且汽紅體外表面形成有複數汽缸體散熱鰭片。 【實施方式】 5 M392874 參考圖4〜7。圖中示出一機車引擎結構，主要包括有 一汽缸頭20、一汽缸體30、及一曲轴箱31。汽缸頭= '汽 缸體30、及曲軸箱31是依序鎖固組合成一體。汽缸體3〇夕= 表面凸設有汽缸體散熱鰭片301，一風扇32組設於曲軸箱η 旁並連結於曲轴知31内之曲轴（圖未示）而同步轉動。一導 風罩34罩蓋於上述汽缸頭20、汽缸體3〇、與曲軸箱31周圍， 用以引導風扇32所抽吸之外界空氣流經特定位置。一排氣 管33連接於汽缸頭20之一排氣口（圖未示）以提供一排放燃 燒廢氣路徑。 汽缸頭20依序鄰接之四側邊外表面分別定義為進氣 側外表面201、點火側外表面2〇2、排氣側外表面2〇3、及鍊 條側外表面204。 進氣側是指引擎中靠近進氣閥門（及進氣閥門27)之一 側，而排氣側指靠近排氣閥門（及排氣閥門座28)之一側， 二者是引擎相對之兩側。鍊條側是指引擎中靠近鍊條容室 8之一側，而點火側與鍊條侧相對。本例中汽缸頭内設有 進氣閥門座27、及二排氣閥門座28，火星塞26設置於約 略中央之位置。 在汽缸頭20之進氣側外表面2〇1突伸有複數進氣側散 熱韓片21、在汽缸頭2〇之排氣側外表面2〇3突伸有複數排氣 側散熱鰭片22。進氣側散熱鰭片2 1與排氣側散熱鰭片22皆 更延伸到點火側外表面2〇2，但互不相連，因此二者之間界 疋出可供冷卻氣流流動之空間，稱火星塞冷卻道25。複 數進氣側散熱鰭片2 1彼此間隔排列而形成複數第一冷卻間 M392874 隙23，複數排氣側散熱鰭片22彼此間隔排列而形成複數第 二冷卻間隙24 β 特別的是，本創作在進氣側散熱鰭片21於點火側外表 面202之部份，鄰接一擋壁29於其端部，使第一冷卻間隙23 不與火星塞冷卻道25連通；但第二冷卻間隙24是連通於火 星塞冷卻道25。擋壁29更可設計成相對於汽缸頭壁面傾斜 者，有助於提升氣流導向表現。 藉由上述結構設計，當外界空氣被風扇吸入，經導風 罩引導至Ά缸體30、汽红頭20，並進入火星塞冷卻道25後， 大部分氣流便撞擊擋壁而轉向往第二冷卻間隙24，如此可 以加強排氣側散熱鰭片22之熱交換作用’使汽缸頭2〇排氣 側溫度獲得更為適當之空氣冷卻作用，改善習知汽缸頭經 冷卻後溫度分佈極不均勻之現象。因此採用本創作汽缸頭 設計可大幅降低排氣閥門座因溫度過高材質劣化、進而影 響引擎性能之情形。 ~ 在製造經濟性之考量下，擋壁29可以與汽缸頭2〇 一體 成型出、也可以與導風罩34—體成型出。 上述實施例僅係為了方便說明而舉例而已，本創作所 主張之權利範圍自應以申請專利範圍所述為準而非僅限 於上述實施例。 【圖式簡單說明】 圖1係習知空冷引擎平面圖。 ®2係第-種習知汽紅頭結構立體圖。 7 M392874 圖3係第二種習知汽紅頭結構立體圖。 圖4係本創作一較佳實施例之引擎立體圖。 圖5係本創作一較佳實施例汽缸頭結構立體圖。 圖6係本創作一較佳實施例汽虹頭底視圖。 圖7係本創作一較佳實施例汽缸頭部分縱剖視圖。 【主要元件符號說明】 汽缸體1 進氣側散熱鰭片2a，8a 第一冷卻間隙2c,8c 導風罩3 火星塞冷卻道5,9 汽缸頭20 點火側外表面202 鍊條側外表面204 排氣側散熱鰭片22 第二冷卻間隙24 火星塞26 排氣閥門座28 汽缸體30 曲轴箱3 1 排氣管33 鍊條容室S 汽缸頭2 排氣側散熱鰭片2b,8b 第二冷卻間隙2d,8d 風扇4 擋壁6,7 進氣側外表面201 排氣側外表面203 進氣側散熱鰭片21 第一冷卻間隙23 火星塞冷卻道25 進氣閥門座27 擋壁29 汽缸體散熱鰭片301 風扇32 導風罩34M392874 V. New description: [New technical field] This creation is about an engine, especially an improved structure suitable for forced air cooling. [Prior Art] The purpose of the locomotive engine cooling system is to avoid engine damage and to prevent damage or to reduce work efficiency. The locomotive cooling system can be divided into an air cooling system and a water cooling system. The former is carried by air around the engine to remove heat. The latter is the resistance of (4) water and cooling; (4) flowing in the engine water jacket to bring Take the heat. Referring to Figure 1, there is a plan view of the air-cooled engine.胄 示出 一 一 一 一 一 一 一 一 一 一 一 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 机 空 空 空 空 空 空 空 空The airflow drawn by a fan 4 is concentratedly blown toward the cylinder block i and the cylinder head 2. Figure 2 and Figure 3 are two perspective views of two different conventional air-cooled engine cylinder heads. In FIG. 2, the cylinder head 2 is formed with a plurality of inlet side heat dissipating fins 2a protruding from the outer surface of the intake side, and a plurality of exhaust side 1 2b adjacent to the intake side of the exhaust side is formed on the outer surface of the exhaust side. The plurality of first cooling gaps 2c are formed to be spaced apart from each other, and the adjacent exhaust side heat dissipating fins 2b are also spaced apart from each other to form a plurality of second cooling gaps 2d. The term "intake" as used herein refers to the side of the W engine near the intake valve and the exhaust side is near one side of the exhaust valve, which are the opposite sides of the engine. Adjacent to the outer side of the intake side 3 M392874 surface and the exhaust side outer surface are the ignition side outer surface. The above two kinds of heat dissipation fins extend to the outer surface of the ignition side, and the plurality of intake side heat dissipation fins 2a and the plurality of exhaust side heat dissipation fins 2b are not connected to the outer surface of the ignition side, and even one of them defines a Mars Plug the cooling channel 5. In particular, in the conventional cylinder head structure, a portion of the intake side heat radiating fin 2a and the exhaust side heat radiating fin 2b on the outer surface of the ignition side are adjacent to a retaining wall 6, 7. Also, due to the presence of the retaining walls 6, 7 'the spark plug cooling passages 5 are not in communication with the first cooling gap 2c and the second cooling gap 2d, the cooling effect on the spark plug can be enhanced. The difference between the engine cylinder head structure of FIG. 3 and FIG. 2 is that the portion of the intake side heat sink fin 8a and the exhaust side heat sink fin 8b on the outer side of the ignition side are not adjacent to the retaining wall, so the spark plug cooling passage 9 is connected to the first cooling gap 8c and the second cooling gap 8d. Thus, not only the cooling air flowing to the spark plug cooling passage 9' but also the first cooling gap 8c and the second cooling gap 8d can be dispersed and enlarged. Cool the area of the cylinder head 2. However, in practice, when the engine is running for a certain period of time, the exhaust side temperature will be significantly higher than other places, and if the temperature of the exhaust valve seat is too high, the material will deteriorate, which will lead to incomplete valve closing and air leakage. Therefore, it is necessary to correct the poor design of the conventional engine cylinder head cooling structure, and to enhance the exhaust side cooling effect to make the overall temperature of the engine more uniform. [New content] The engine improved structure of this creation includes a cylinder head, an air hood, a plurality of air inlet side thermal film, and a plurality of ventilating side heat sinks. The cylinder head M392874 includes an intake side outer surface, an ignition side outer surface, and an exhaust side outer surface, the ignition side outer surface being adjacent to the intake side outer surface and the gas side outer surface, respectively. The air hood cover is around the cylinder head. The intake side heat dissipating fins project from the outer surface of the intake side and extend to the outer surface of the ignition side, and are spaced apart from each other to form a plurality of first cooling gaps. The exhaust side heat dissipating fin protrudes from the exhaust side outer surface and extends to the ignition side outer surface, and is spaced apart from each other to form a plurality of second cooling gaps, wherein on the ignition side outer surface, the plurality of intake side heat dissipation A spark plug cooling channel is defined between the fin and the plurality of exhaust side fins. The present invention is characterized in that the second cooling gap is in communication with the spark plug cooling passage, and a portion of the intake side heat radiating fin adjacent to the outer surface of the ignition side is adjacent to a retaining wall, and the retaining wall isolates the spark plug cooling passage from the first cooling gap. Connected. With the improved structure described above, after the cooling air flows to the cooling channel of the spark plug, the wall is blocked from flowing to the first cooling gap, that is, the ratio of the cooling effect of the cooling fins on the intake side is reduced, and the exhaust side fins are also taken into consideration. Cooling of the film. Therefore, the overall temperature distribution of the engine is more uniform than the conventional structure, reducing the damage of the valve seat. The retaining wall may be integrally formed with the cylinder head or may be integrally formed with the air deflector. The cylinder head may further include two intake valve seats and two exhaust valve seats. The engine improved structure may further include a cylinder system coupled to the vapor head, and a plurality of cylinder block fins are formed on the outer surface of the vapor red. [Embodiment] 5 M392874 refers to Figs. 4 to 7. The figure shows a locomotive engine structure mainly comprising a cylinder head 20, a cylinder block 30, and a crankcase 31. Cylinder head = 'The cylinder block 30 and the crankcase 31 are sequentially locked and integrated into one. The cylinder block 3 has a cylinder block heat dissipation fin 301 protruding from the surface, and a fan 32 is disposed adjacent to the crankcase η and coupled to the crankshaft (not shown) in the crankshaft 31 to rotate synchronously. A hood 34 is disposed around the cylinder head 20, the cylinder block 3, and the crankcase 31 for guiding the fan 32 to draw the outside air through a specific position. An exhaust pipe 33 is coupled to an exhaust port (not shown) of the cylinder head 20 to provide an exhaust combustion exhaust path. The four outer side surfaces adjacent to the cylinder head 20 are defined as an intake side outer surface 201, an ignition side outer surface 2', an exhaust side outer surface 2'3, and a chain side outer surface 204, respectively. The intake side refers to one side of the engine near the intake valve (and the intake valve 27), and the exhaust side refers to one side of the exhaust valve (and the exhaust valve seat 28), which are the opposite of the engine side. The chain side refers to one side of the engine near the chain chamber 8, and the ignition side is opposite to the chain side. In this example, the cylinder head is provided with an intake valve seat 27 and two exhaust valve seats 28, and the spark plug 26 is disposed at approximately the center. A plurality of intake side heat dissipating fins 21 are protruded from the intake side outer surface 2〇1 of the cylinder head 20, and a plurality of exhaust side fins 22 are protruded from the exhaust side outer surface 2〇3 of the cylinder head 2〇. . Both the intake side fins 21 and the exhaust side fins 22 extend to the ignition side outer surface 2〇2, but are not connected to each other, so that the space between the two flows out for the cooling airflow, Mars plugs the cooling channel 25. The plurality of intake side fins 2 1 are spaced apart from each other to form a plurality of first cooling chambers M392874, and the plurality of exhaust side fins 22 are spaced apart from each other to form a plurality of second cooling gaps 24 β. The portion of the intake side heat sink fin 21 on the ignition side outer surface 202 is adjacent to a stop wall 29 at its end such that the first cooling gap 23 is not in communication with the spark plug cooling passage 25; however, the second cooling gap 24 is connected On the Mars plug cooling channel 25. The retaining wall 29 can be designed to be inclined relative to the cylinder head wall surface to help improve airflow directing performance. With the above structural design, when the outside air is sucked by the fan, guided to the cylinder block 30, the steam red head 20 through the air hood, and enters the spark plug cooling passage 25, most of the airflow hits the retaining wall and turns to the second. Cooling gap 24, which can enhance the heat exchange effect of the exhaust side fins 22, so that the cylinder head 2 〇 exhaust side temperature can obtain more appropriate air cooling effect, and the temperature distribution of the conventional cylinder head after cooling is extremely uneven. The phenomenon. Therefore, the design of the cylinder head of the present invention can greatly reduce the deterioration of the exhaust valve seat due to excessive temperature and the performance of the engine. ~ In consideration of manufacturing economy, the retaining wall 29 may be integrally formed with the cylinder head 2〇 or may be integrally formed with the air guiding cover 34. The above-described embodiments are merely examples for convenience of description, and the scope of the claims is intended to be based on the scope of the patent application and not limited to the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a conventional air-cooled engine. ® 2 is a stereoscopic view of the first known steam red head structure. 7 M392874 Figure 3 is a perspective view of a second known steam red head structure. 4 is a perspective view of an engine of a preferred embodiment of the present invention. Fig. 5 is a perspective view showing the structure of a cylinder head according to a preferred embodiment of the present invention. Figure 6 is a bottom view of the steam head of a preferred embodiment of the present invention. Figure 7 is a longitudinal cross-sectional view of a cylinder head portion of a preferred embodiment of the present invention. [Main component symbol description] Cylinder block 1 Inlet side heat sink fins 2a, 8a First cooling gap 2c, 8c Air hood 3 Mars plug cooling channel 5, 9 Cylinder head 20 Ignition side outer surface 202 Chain side outer surface 204 Row Airside fins 22 Second cooling gap 24 Mars plug 26 Exhaust valve seat 28 Cylinder block 30 Crankcase 3 1 Exhaust pipe 33 Chain chamber S Cylinder head 2 Exhaust side fins 2b, 8b Second cooling gap 2d, 8d fan 4 retaining wall 6, 7 intake side outer surface 201 exhaust side outer surface 203 intake side heat sink fin 21 first cooling gap 23 spark plug cooling channel 25 intake valve seat 27 block wall 29 cylinder block heat dissipation Fin 301 fan 32 air hood 34