200530495 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種内燃機，特別係關於一種於吸氣通路 内具備蝶式之節流閥之内燃機。 【先前技術】 作為於吸氣通路内具備蝶式節流閥之内燃機，可列舉出 例如專利文獻1所示者。專利文獻1所揭示之内燃機示於圖 1 ° 如圖1所示，於燃燒室211中設有自氣缸202之外部貫通之 吸氣通路212，該吸氣通路212之下游側形成於氣缸頭部2 〇 7 之後部，於前後方向延伸。吸氣通路2 12之上游側形成於連 接於氣缸頭部207之後面側的吸氣管213内。於該吸氣管213 内設有開閉吸氣通路212之節流閥214，該節流閥214係蝶式 者。 再者，吸氣管213之吸氣通路212之上游端通過空氣濾清 器連通至大氣側。又，於相比節流閥214更下游側之吸氣通 路212内設有喷射燃料216而供給之燃料喷射閥217。 於引擎201運轉時，活塞209自上死點朝向下死點下降時 為吸入行程，此時藉由吸氣閥229之開閥動作打開吸氣開口 部228。然後，藉由燃燒室211以及吸氣通路212内之負壓， 自氣紅202之外部吸入空氣250。 此時’對於通過吸氣通路212之空氣250，燃料噴射閥217 喷射燃料216，藉此產生混合氣25卜該混合氣251於燃燒室 211内為滾動流（向左右延伸之繞軸心旋轉之旋轉流）252。 97469.doc 200530495 於引擎201之低負荷時，減少供給至燃燒室211之燃料216 之數量增大空氣燃料比之值，但混合氣25丨作為滾動流 252 ’該主流部可面向放電部246，因此可更為確實地點火 到達該放電部246之濃度較高之上述混合氣25 1，並且立刻 產生火焰核，迅速地實行火焰傳播。其結果係可實現引擎 性能之提高。 專利文獻1:曰本專利特開平8_218875號公報 發明所欲解決之課題 為促進滾動流，通過燃燒室211之吸氣通路（吸氣口）之形 狀較為重要，藉由吸氣口之設計，可實現促進滾動流之強 度之情形較多（例如，參照日本專利實開平‘137224號公 )又於二轉時或低負荷時產生滾動流之情形較好，即 便如此於超過上述之高負荷時，較好的是藉由燃料濃度比 較均-之混合氣（均-燃燒）運轉引擎（例如，參照日本專利 特開平9.3175G5號公報）。無論何種燃燒形態，使滾動流產 生後谷易招致如下結果··於燃燒室内氣體流動不均一散 佈，燃燒效率降低，或輸出降低，燃費惡化。因此，使用 閥可變機㈣由控制第i吸氣闕、第2以及第3吸氣閥之開 關動作，可調整滾動流之形成。 造變f使機構後，當然與未使用該機構時相比揭 僅導致成本提高，亦容易不適用於如自動 一輪車之配置空間極其有限之引擎。 =明係寥於相關點開發而成者，其主要目的在於提供 燃機’該内燃機可以簡單之構成產生滾動流且可調 97469.doc 200530495 整滾動流之形成。 【發明内容】 本發明之内燃機，其特徵在於：其係含有燃燒室，以及 導入空亂至上述燃燒室之吸氣管者，於上述吸氣管内配置 ㈣整導入至上述燃燒室之空氣之流入量的節流閥，上述 即流閥含有第1端部，以及位於上述第丨端部之相反位置的 第2端部，於上述吸氣管内部之上述節流閥之上游設有階 差，其與面向該節流閥之第i端部之空氣流相比，增強面向 上述第2端部之空氣流。 於某合適之實施形態中，上述節流閥係蝶式之節流閥， 於上述第1端部與上述第2端部之間，形成有樞支上述節流 閥之搞支轴。 於某合適之實施形態中，上述節流閥之上述第2端部以上 述樞支轴為中心，向下游來回轉動，藉此實行上述節流閥 之開、關閥動作。 於某合適之實施形態中，上述階差配置於上述節流閥之 上述第1端部之附近較好。 上述附近處於如下區域較好··與上述節流閥完全關閉時 之上述第1端部之位置相比更上游，與自上述第1端部與上 述第2端部之中央位置距離2個上述節流閥全長程度之位置 相比更下游之間之區域。 於某合適之實施形態中，上述階差之至少一部分存在於 與上述節流閥完全關閉時之上述第丨端部之位置相比更上 游，與上述節流閥完全打開時之上述第丨端部之位置相比更 97469.doc 200530495 下游之間的區域。 於某合適之實施形態中，上述階差包含上述吸氣管之上 游側之内面，以及自上述上游側之内面延伸之壁面，上述 上游側之内面與上述壁面所成之角大致呈直角。 上述階差包含上述吸氣管之上游側之内面，以及自上述 上游侧之内面延伸之壁面，上述上游侧之内面與上述壁面 所成之角亦可為鈍角。 於某合適之實施形態中，上述吸氣管内，上述第2端部側 之内面為面―，其位於設置有上述階差之上述第1端部側之 内面相反之位置。 於某合適之實施形態中，至少設有階差之上述吸氣管之 部位藉由一體成形而形成。 於某合適之實施形態中，於比該第丨部分更下游側，對於 以接近該部分之方式而配置的第2部分之剖面中心線，於上 述吸氣管之縱方向，使比上述吸氣管中之上述節流閥更上 游側的第1部分之剖面中心線偏向上述節流閥之第2端部 側，藉此形成上述階差。 於某合適之實施形態中，上述第！部分與第2部分之各剖 面形狀分別為圓形。 於某合適之實施形態中’其特徵在於：於上述燃燒室之 P之側方配置有開關上述吸氣管的出口之提昇閥，自 上述吸氣管之出口向上述吸翁瞢 <及巩g之上游延伸之方向係向上 述一側方之斜上方延伸$ t A , i 开万m方肖，上述吸氣管中之上述第2端 部側之内面向下游延伸後， ^ 到違上述燃燒室之上部之中心 97469.doc 200530495 側。 於某合適之實施形態中，其特徵在於：比上述節流間更 處於下游之上述吸氣管彎曲為大致圓弧狀到達上述燃燒室 之上部。 於某合適之實施形態中，以1個上述燃燒室為單位，設置 1個以上的上述節流閥於上述吸氣管内。 於某合適之實施形態中，上述節流閥係可將導入至上述 燃燒室之空氣量最多降低至空轉所必需之空氣量的吸氣 閥。 、 本發明之自動二輪車係具備上述内燃機之自動二輪車。 本發明之實施形態之内燃機，其特徵在於：設有蝶式之 節流閥，該節流閥配置於使大氣側連通至氣缸内之吸氣通 路以可開關之方式關閉該吸氣通路，樞支上述吸氣通路 之縱方向之上述節流閥之中途部至形成上述吸氣通路之構 :，以該樞支軸心為中心上述節流閥之一端部側面向上述 乳缸側來回轉動，藉此於該節流閥可進行開、關閥動作之 内燃機中，於比該第1部分更下游側，對於以接近該第一部 分之方式而配置的上述吸氣通路之第2部分之剖面中心 線’：上述吸氣通路之縱方向，纟比上述節流閥更上游側 的吸氣通路之第1部分的剖面中心線偏向上述節流閥之一 端部側。 ;某貫苑形態中，其特徵為使上述第〗部分位於上述宁 閥之附近。 抓 ;某貫施形態中，其特徵為分別使上述第丨部分與第2部 97469.doc 200530495 分之各剖面形狀為圓形。 於某實施形態中，其特徵為··於上述吸氣通路之長声方 向，使上述碎流閥之轉動執跡，以及自上述第丨部分變化至 第2部分之變化部分之至少一部分位於相互相同之位置。至 於某實施形態中，其特徵為··於上述吸氣通路之長度方 向，使上述節流閥之轉動執跡，以及上述第丨部分之至少一 部分位於相互相同之位置。 於某實施形態中’其特徵為：使比上述節流閥下游侧之 吸氣通路之第3部分，以其剖面中心線呈圓弧形狀之方式弯 曲，於上述吸氣通路之第3部分之縱方向，使該第3部分之 内面中之f曲半徑較大側與上述節流閥之—端部側位於相 互相同側。 ，於某實施形態中’其特徵為：仙有上述節流閥之吸氣 管之部分為鑄造製，於該鑄造製之吸氣管之部分中，於上 述吸氣通路之長度方向，藉由機械加工，僅成形位於與上 述節流閥大致相同位置的上述第2部份之内面。 [發明之效果] 藉由本發明之内燃機’於吸氣管内之節流閥之上游設有 階差’該階差與面向該節流閥之第!端部之空氣流相比，加 強面向第2端部之空氣流’因此於燃燒室中可產生更明確之 滾動流。X，於高負荷時，節流閥之開口程度變大，因此 自第1端部附近之開口流出之空氣流之量與自第2端部附近 之開口流出之空氣流之量的差自然變小，其結果係可調整 滾動流之形成。即，藉由本發明之内燃機，可以簡單之構 97469.doc -11 · 200530495 成產生滚動流以及調整滾動流之形成。 【實施方式】 本申請案發明者發現，以簡單之構成使滾動流成為更明 確者，且專心研究以簡單之構成調整滾動流之形成（即，於 低負荷時形成滾動流，於高負荷時，自滾動流轉移為均一 流）之結果，不是變化燃燒室周邊之吸氣口之形狀（設計變 更）’或適用閥可變機構，而是對節流閥周邊之構造進行設 計’藉此可獲得此種效果，從而完成本發明。 以下’ 一面參照圖式，一面說明本發明之實施形態。再 者，本發明並非限定於以下之實施形態。 一面參照圖2至圖4，一面就本發明之實施形態丨之内燃機 加以說明。圖2係模式性表示本實施形態之内燃機1 〇〇之構 成的剖面圖。圖3(a)係節流閥之周邊之主要部分之放大剖面 圖，圖3(b)係沿著圖3(a)中之線ΠΒ-ΙΠΒ之剖面圖。圖4係用 以模式性說明本實施形態之内燃機1 〇〇之動作之圖。 本實施形態之内燃機100如圖2所示，含有燃燒室1〇，以 及導入空氣至燃燒室10之吸氣管（吸氣口）20。於吸氣管2〇 内配置有調整導入至燃燒室10之空氣之流入量的節流閥 30。於本實施形態中，節流閥30設置於吸氣管20之一部22， 含有第1端部30a以及第2端部30b。 如圖3所示，於吸氣管20(22)内部中，於節流閥30之上游 51設有階差40，該階差比面向該節流閥30之第1端部30a之 空氣50之流，增強面向第2端部3Ob之空氣50之流。即，如 圖4所示，藉由階差40之存在，自上游51向節流閥30之方向 97469.doc -12- 200530495 之空氣50之流，係與面向第1端部3〇a之流5〇a相比，面向第 2端部3 Ob之流5 Ob較強。於是，圖中，自上側之第j端部3〇a 所流出之流50b沿著吸氣管2〇之上側的内面28向下游52移 動’導入至燃燒至10内後’形成滾動流5 5。 如此’藉由設置階差40，該階差加強面向第2端部3〇b之 空氣之流50b，導入至燃燒室10之空氣成為更明確之滾動流 5 5 ’其結果可獲得良好之著火性，以及迅速之火焰傳播， 可進一步提高引擎性能。 另一方面，於節流閥30較大地打開的高負荷之時（例如， 節流閥全開時），如圖5所示，階差40之影響變得微弱，空 氣5 0於圖中亦流動於上方（5〇b)亦流動於下方（5〇a)，導入該 等至燃燒室10，因此可形成均一（非滾動流）之混合氣。 本貫施形態之卽流閥3 0係蝶式之節流閥，於第1端部3 〇a 與第2端部30b之間，形成有樞支節流閥30之樞支轴31。節 流閥3 0之第2端部3 Ob以樞支軸3 1為中心，向下游52來回轉 動，藉此實行節流閥30之開、關閥動作。因此，若該等動 作得以實行，並非如圖示之例僅限於上側之情形，例如第2 端部30b亦可於下側。 如圖3所示，階差40配置於節流閥30之第1端部30a之附 近。即，階差40於節流閥30之空隙情況（即，第2端部3扑與 吸氣管20(22)之間之間隙）較小時，換言之，於空轉或低負 荷時’必需以加強面向第2端部30b的空氣流50b之方式發揮 功能，因此形成於發揮該功能之位置。 若加強面向第2端部30b之空氣流50b，亦可結合内燃機 97469.doc -13- 200530495 100之條件·規袼等，設定階差4〇之位置為恰當合適者。例 如，Ρό差40亦可設置於與節流閥3〇完全關閉時的第i端部 3 0a之位置相比上游（5丨）’與自第1端部3〇a與第2端部3〇1)之 中央位置（即，樞支軸31)距離2個節流閥3〇全長的位置相比 下游（52)之間的區域。 較好的是，階差40形成於與節流閥3〇完全關閉時的第1 端部30a之位置相比上游，與節流閥3〇完全打開時的第1端 部30a之位置相比下游之間的區域。其原因在於：若形成於 此種區域’則可提高加強面向第2端部3Ob之空氣流50b之效 果。反之，即使於遠離第i端部3〇a之附近之處（例如，與圖 2中吸氣管20之一部分22相比上游之部位23的一部分）存在 階差（或者，構成階差之凹部），其並非可加強面向第2端部 30b之空氣流50b者’因此不適用於本實施形態之階差4〇。 本實施形態之階差40大致呈直角。即，階差4〇包含吸氣 管20之上游侧（51)之内面25，以及自上游側（51)之内面25延 伸之壁面27，上游側之内面25與壁面27所成角大致呈直 角。再者，若為上述之可發揮加強面向第2端部3 Ob之空氣 流50b的效果之階差40，亦可為鈍角者。 再者，藉由一體成形可形成設有階差40之吸氣管20之部 位22。於本實施形態中，形成設有節流閥3〇之吸氣管2〇之 部位22作為節流閥本體，然後，該節流閥本體22之階差4〇 藉由一體成形與内面24、25、26—併形成。當然，亦可加 工内面24、25之一部分，形成階差40。 於本實施形態所示之例中，於吸氣管20(22)之内，第2端 97469.doc -14· 200530495 其位於設有階差40的第1端部30a200530495 IX. Description of the invention: [Technical field to which the invention belongs] The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine having a butterfly type throttle valve in an intake passage. [Prior Art] As an internal combustion engine having a butterfly throttle valve in an intake passage, for example, as shown in Patent Document 1. The internal combustion engine disclosed in Patent Document 1 is shown in FIG. 1 ° As shown in FIG. 1, the combustion chamber 211 is provided with an intake passage 212 penetrating from the outside of the cylinder 202, and the downstream side of the intake passage 212 is formed at the cylinder head 〇7 The rear part extends in the front-back direction. The upstream side of the intake passage 212 is formed in an intake pipe 213 connected to the rear side of the cylinder head 207. A throttle valve 214 for opening and closing the suction passage 212 is provided in the suction pipe 213, and the throttle valve 214 is a butterfly type. The upstream end of the suction passage 212 of the suction pipe 213 is communicated to the atmospheric side through an air filter. A fuel injection valve 217 for supplying fuel 216 is provided in the intake passage 212 downstream of the throttle valve 214. When the engine 201 is running, when the piston 209 descends from the top dead center toward the bottom dead center, it is an intake stroke. At this time, the intake opening portion 228 is opened by the opening operation of the intake valve 229. Then, the negative pressure in the combustion chamber 211 and the suction passage 212 sucks air 250 from the outside of the gas red 202. At this time, 'for the air 250 passing through the intake path 212, the fuel injection valve 217 injects fuel 216, thereby generating a mixed gas 25. The mixed gas 251 is a rolling flow in the combustion chamber 211. Rotating flow) 252. 97469.doc 200530495 When the engine 201 is at a low load, reduce the amount of fuel 216 supplied to the combustion chamber 211 and increase the value of the air-fuel ratio, but the mixed gas 25 丨 as the rolling flow 252 'This mainstream portion can face the discharge portion 246, Therefore, it is possible to more surely ignite the above-mentioned mixed gas 251 having a higher concentration to reach the discharge portion 246, and immediately generate a flame nucleus to rapidly perform flame propagation. The result is an improvement in engine performance. Patent Document 1: Japanese Patent Laid-Open No. 8-218875 The problem to be solved by the invention is to promote rolling flow. The shape of the intake passage (suction port) passing through the combustion chamber 211 is more important. The design of the intake port can It is often the case to achieve the strength of the rolling flow (for example, refer to Japanese Patent Shikaihei No. 137224), and it is better to generate the rolling flow at the second turn or at a low load, even when the above high load is exceeded It is preferred that the engine be operated by a fuel mixture (homo-combustion) with a relatively uniform fuel concentration (for example, refer to Japanese Patent Laid-Open No. 9.3175G5). Regardless of the type of combustion, Gu Yi caused the following results after the generation of rolling flow ... The gas flow in the combustion chamber is unevenly distributed, the combustion efficiency is reduced, or the output is reduced, and the fuel consumption is deteriorated. Therefore, the use of the valve variable mechanism ㈣ can control the opening and closing operations of the i-th intake valve, the second and third intake valves, and can adjust the formation of the rolling flow. After the f mechanism is changed, of course, compared with when the mechanism is not used, it will only lead to an increase in cost, and it is also not suitable for engines with extremely limited configuration space, such as a motorcycle. = The Ming Department was developed by a few related points. Its main purpose is to provide gas turbines. The internal combustion engine can be simply constructed to generate a rolling flow and is adjustable. 97469.doc 200530495 The formation of a complete rolling flow. [Summary of the Invention] The internal combustion engine of the present invention is characterized in that it includes a combustion chamber and an intake pipe that is introduced into the combustion chamber, and arranges the inflow of the air introduced into the combustion chamber in the intake pipe. The throttle valve includes a first end portion and a second end portion located opposite to the first end portion. A step is provided upstream of the throttle valve inside the suction pipe. Compared with the air flow facing the i-th end portion of the throttle valve, it enhances the air flow facing the second end portion. In a suitable embodiment, the throttle valve is a butterfly-type throttle valve, and a support shaft pivotally supporting the throttle valve is formed between the first end portion and the second end portion. In a suitable embodiment, the second end portion of the throttle valve is centered on the pivot shaft above and below, and pivoted back and forth downstream to perform the opening and closing operations of the throttle valve. In a suitable embodiment, the step is preferably arranged near the first end portion of the throttle valve. The vicinity is preferably located in the following area ... It is more upstream than the position of the first end portion when the throttle valve is fully closed, and is two distances from the center position of the first end portion and the second end portion. The position of the full length of the throttle valve is compared with the area further downstream. In a suitable embodiment, at least a part of the step exists more upstream than the position of the first end portion when the throttle valve is fully closed, and the first end portion when the throttle valve is fully opened. The location of the department is more than the area between 97469.doc and 200530495 downstream. In a suitable embodiment, the step includes the inner surface on the upstream side of the suction pipe and a wall surface extending from the inner surface on the upstream side, and the angle formed by the inner surface on the upstream side and the wall surface is approximately right angles. The step includes the inner surface on the upstream side of the suction pipe and a wall surface extending from the inner surface on the upstream side. The angle formed by the inner surface on the upstream side and the wall surface may be an obtuse angle. In a suitable embodiment, the inner surface of the second end portion side in the suction pipe is a surface, which is located opposite to the inner surface of the first end portion side where the step is provided. In a suitable embodiment, at least a part of the above-mentioned suction pipe provided with a step is formed by integral molding. In a suitable embodiment, the centerline of the cross section of the second portion disposed closer to the portion on the downstream side than the first portion is in the longitudinal direction of the suction pipe to make the suction more than the above. The section centerline of the first portion of the throttle valve on the upstream side of the pipe is deviated toward the second end portion side of the throttle valve, thereby forming the step. In a suitable embodiment, the above is the first! The cross-sectional shapes of the part and the second part are respectively circular. In a suitable embodiment, it is characterized in that a poppet valve that opens and closes the outlet of the suction pipe is arranged on the side of P of the combustion chamber, and from the outlet of the suction pipe to the suction pipe < and The direction of the upstream extension of g is to extend diagonally above the one side. $ t A, i 10,000 m square shaw. After the inner side of the second end side of the suction pipe extends downstream, ^ to violate the above. The center of the upper part of the combustion chamber is 97469.doc 200530495 side. In a suitable embodiment, the suction pipe, which is further downstream than the throttle, is bent into a substantially arc shape and reaches the upper part of the combustion chamber. In a suitable embodiment, one or more of the above-mentioned throttle valves are provided in the above-mentioned intake pipe in units of one of the above-mentioned combustion chambers. In a suitable embodiment, the throttle valve is an intake valve that can reduce the amount of air introduced into the combustion chamber up to the amount of air necessary for idling. The two-wheeled vehicle of the present invention is a two-wheeled vehicle provided with the internal combustion engine. An internal combustion engine according to an embodiment of the present invention is characterized in that a butterfly-type throttle valve is provided, and the throttle valve is arranged to close an intake passage that connects the atmosphere side to the cylinder in a switchable manner. The middle part of the throttle valve supporting the longitudinal direction of the suction path to the formation of the suction path: the side of one end of the throttle valve with the pivot axis as the center is turned back and forth to the breast cylinder side, With this, in the internal combustion engine in which the throttle valve can be opened and closed, the center of the cross section of the second part of the above-mentioned intake passage arranged closer to the first part on the downstream side than the first part Line ': In the longitudinal direction of the intake passage, the cross-section center line of the first portion of the intake passage that is more upstream than the throttle is deviated toward one end side of the throttle. ; In the form of a Guanyuan, it is characterized in that the above part 〖is located near the above Ning valve. In the form of a constant application, it is characterized in that the cross-sectional shapes of the above part 丨 and the second part 97469.doc 200530495 are rounded. In an embodiment, it is characterized in that at least a part of the rotation of the choke valve and at least a part of the change from the first part to the second part in the long sound direction of the suction path are located in each other Same location. As for an embodiment, it is characterized in that the rotation of the throttle valve and at least a part of the above-mentioned part in the direction of the length of the suction path are located at the same position with each other. In one embodiment, it is characterized in that the third part of the intake passage which is downstream of the throttle valve is curved in such a manner that the center line of the cross section is in an arc shape, and In the longitudinal direction, the side with a larger f-curve radius in the inner surface of the third portion and the end portion side of the throttle valve are located on the same side as each other. In a certain embodiment, it is characterized in that the part of the suction pipe having the above-mentioned throttle valve is made of casting, and the part of the suction pipe made of this casting is in the length direction of the above-mentioned suction passage by Machining only the inner surface of the second part located at the same position as the throttle valve. [Effect of the invention] With the internal combustion engine of the present invention, 'a step is provided upstream of the throttle valve in the intake pipe', the step difference is strengthened toward the second side compared with the airflow facing the! End of the throttle valve. The air flow at the ends can thus produce a more specific rolling flow in the combustion chamber. X. At high load, the opening degree of the throttle valve becomes larger, so the difference between the amount of air flow flowing from the opening near the first end and the amount of air flow flowing from the opening near the second end naturally changes. Small, the result is adjustable roll flow formation. That is, with the internal combustion engine of the present invention, it is possible to easily construct 97469.doc -11 · 200530495 to generate a rolling flow and adjust the formation of the rolling flow. [Embodiment] The inventor of the present application has found that the rolling flow is made clearer with a simple structure, and the research is focused on adjusting the formation of the rolling flow with a simple structure (that is, forming a rolling flow at a low load and a high load). As a result, the rolling flow has been transferred to a first-class level), instead of changing the shape of the suction port around the combustion chamber (design change) or applying a variable valve mechanism, but designing the structure around the throttle valve, so that Such an effect is obtained, thereby completing the present invention. Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments. Referring to Figs. 2 to 4, the internal combustion engine according to the embodiment of the present invention will be described. Fig. 2 is a cross-sectional view schematically showing the structure of the internal combustion engine 1000 of this embodiment. Fig. 3 (a) is an enlarged cross-sectional view of the main part of the periphery of the throttle valve, and Fig. 3 (b) is a cross-sectional view taken along the line II-IB in Fig. 3 (a). Fig. 4 is a diagram for schematically explaining the operation of the internal combustion engine 1000 in this embodiment. As shown in FIG. 2, the internal combustion engine 100 of this embodiment includes a combustion chamber 10 and an intake pipe (intake port) 20 for introducing air into the combustion chamber 10. A throttle valve 30 is disposed in the intake pipe 20 to adjust the inflow amount of the air introduced into the combustion chamber 10. In this embodiment, the throttle valve 30 is provided in one part 22 of the suction pipe 20, and includes a first end portion 30a and a second end portion 30b. As shown in FIG. 3, in the inside of the suction pipe 20 (22), a step 40 is provided upstream 51 of the throttle valve 30, and the step ratio is higher than the air 50 facing the first end portion 30a of the throttle valve 30 The flow enhances the flow of air 50 facing the second end portion 3Ob. That is, as shown in FIG. 4, the flow of air 50 from the upstream 51 to the direction of the throttle valve 30 from the upstream 51 to the direction of the throttle valve 30 is 97469.doc -12- 200530495 due to the existence of the step 40, which is the same as that facing the first end portion 30a. The stream 5 Ob facing the second end 3 Ob is stronger than the stream 50a. Then, in the figure, the flow 50b flowing out from the j-th end portion 30a on the upper side is moved downstream 52 along the inner surface 28 on the upper side of the suction pipe 20, and “rolled into the combustion chamber after being introduced into 10” 5 5 . In this way, by setting the step 40, the step enhances the air flow 50b facing the second end portion 30b, and the air introduced into the combustion chamber 10 becomes a more specific rolling flow 5 5 ', and as a result, a good fire can be obtained Performance, and rapid flame propagation can further improve engine performance. On the other hand, when the throttle valve 30 is opened at a high load (for example, when the throttle valve is fully opened), as shown in FIG. 5, the effect of the step 40 becomes weak, and air 50 also flows in the figure. Above (50b) also flows below (50a), and these are introduced into the combustion chamber 10, so a uniform (non-rolling flow) mixed gas can be formed. The choke valve 30 of the present embodiment is a butterfly type throttle valve, and a pivot shaft 31 of a pivot valve 30 is formed between the first end portion 30a and the second end portion 30b. The second end 3 Ob of the throttle valve 30 is centered on the pivot shaft 31 and pivots downstream 52 to perform the opening and closing operations of the throttle valve 30. Therefore, if these actions are carried out, the example is not limited to the upper side, as shown in the figure, for example, the second end portion 30b may be on the lower side. As shown in Fig. 3, the step 40 is arranged near the first end portion 30a of the throttle valve 30. That is, when the gap between the step 40 and the throttle valve 30 (that is, the gap between the second end 3 flap and the suction pipe 20 (22)) is small, in other words, during idling or low load, it is necessary to use The function of strengthening the air flow 50b facing the second end portion 30b is formed, and thus it is formed at a position where the function is exerted. If the air flow 50b facing the second end portion 30b is strengthened, the conditions and regulations of the internal combustion engine 97469.doc -13- 200530495 100 may be used to set the position of the step 40 to be appropriate. For example, the difference 40 may be provided upstream (5 丨) ′ from the position of the i-th end portion 30a when the throttle valve 30 is completely closed, and from the first end portion 30a and the second end portion 3 〇1) The center position (that is, the pivot 31) is located from the position between the two throttles 30 full length compared to the area between the downstream (52). Preferably, the step 40 is formed upstream from the position of the first end portion 30a when the throttle valve 30 is fully closed, and compared to the position of the first end portion 30a when the throttle valve 30 is fully opened. The area between the downstream. The reason for this is that if formed in such a region ', the effect of strengthening the air flow 50b facing the second end portion 3Ob can be enhanced. Conversely, even if there is a step difference (or a concave portion constituting the step difference) even in the vicinity of the i-th end portion 30a (for example, a portion of the portion 23 upstream from the portion 22 of the suction pipe 20 in FIG. 2). ), Which does not enhance the air flow 50b facing the second end portion 30b, and therefore is not suitable for the step difference 40 of this embodiment. The step 40 of this embodiment is substantially at a right angle. That is, the step 40 includes the inner surface 25 of the upstream side (51) of the suction pipe 20 and the wall surface 27 extending from the inner surface 25 of the upstream side (51). The angle formed by the inner surface 25 of the upstream side and the wall surface 27 is approximately a right angle. . Furthermore, if it is the above-mentioned step difference 40 that can exert the effect of enhancing the air flow 50b facing the second end portion 3 Ob, it can also be an obtuse angle. Furthermore, the unit 22 of the suction pipe 20 provided with the step 40 can be formed by integral molding. In this embodiment, a portion 22 of the suction pipe 20 provided with the throttle valve 30 is formed as a throttle body, and then the step difference 40 of the throttle body 22 is formed integrally with the inner surface 24, 25, 26—and formed. Of course, it is also possible to process a part of the inner surfaces 24 and 25 to form a step difference 40. In the example shown in this embodiment, within the suction tube 20 (22), the second end 97469.doc -14 · 200530495 is located at the first end 30a provided with a step 40
氣流50b的功能。 部30b側之内面26成面一 側之内面（24、25)相反:^ 階差40例如圖3(b)所示，使節流閥3〇所處之部分（内面24 所處之吸氣管20之部位），以及位於與其相比上游之部分（内 面25所處之吸氣管20之部位）偏位，藉此形成階差⑽。進而 加以說明，於比第1部分更為下游側，對於以接近該部分之 方式而配置的第2部分之剖面中心線〇〗，於吸氣管2〇之縱方 向使比吸氣管20中之節流閥3〇更為上游側的第1部分之剖 面中心線02偏向節流閥30之第2端部30b側，藉此形成上述 階差。此處，第1部分以及第2部分之各剖面形狀分別呈圓 形。圖中，位於上方之内面26，第1部分與第2部分一致， 藉由位於下方之内面25與内面24之偏差，形成階差40。 於本實施形態之内燃機1 0 0中，如圖4等所示，於燃燒室 10之上部之一側方，設有開關吸氣管20之出口 15之吸氣閥 (提昇閥）14，自吸氣管20之出口 15向吸氣管20之上游（51) 延伸之方向係向上述一側方之斜上方延伸之方向。且，吸 氣管20中之第2端部3Ob侧之内面28向下游（52)延伸後，到達 燃燒室10之上部之中心側。以此方式構成吸氣管20，藉此 可較容易地形成滾動流55。於本實施形態中，與節流閥3〇 相比下游（52)之吸氣管20具有以下構造：以大致圓弧形狀弯 曲，到達燃燒室10之上部。 97469.doc -15- 200530495 再者，於燃燒室1〇之上部之其它方側，設有排氣闕（提昇 閥）16,於排氣閥16之裏面安裝有排氣管（排氣口）Μ。燃婷 . 室10内之活塞丨2上下來回振動，實行錢動.燃燒^ · 之各行程。出於方便考慮，說明中使用圖中 〜工卜關係， 本實施形態之内燃機100不配置圖中之上方於上方亦。 節流閥30以即使於完全關閉之情形時亦使空轉所:需之 空氣50通過之方式設計，換言之，節流閥3〇係可將導入至 燃燒室10之空氣量50降低至至多空轉所必需之空氣量的吸 氣閥（蝶式閥）。於節流閥30之下游（52)侧，設有燃燒喷射閥_ (未圖不），對於自節流閥3〇流出之吸氣（5〇b)，燃料喷射閥 喷射燃料，藉此產生混合氣，且該混合氣於燃燒室1〇内形 成滾動流55。 乂Function of air flow 50b. The inner surface 26 on the side of the portion 30b is opposite to the inner surface (24, 25) on the side of the surface: ^ The step 40 is shown in FIG. 3 (b), so that the part where the throttle valve 30 is located (the suction pipe where the inner surface 24 is located 20), and the portion upstream of it (the location of the suction tube 20 on the inner surface 25) is deviated, thereby forming a step difference. Further, on the downstream side from the first part, the center line of the cross section of the second part arranged so as to be close to the part 〇 is placed in the longitudinal direction of the suction pipe 20 than the suction pipe 20. The throttle valve 30 is further biased toward the second end portion 30b side of the throttle valve 30 by the cross section centerline 02 of the first portion on the upstream side, thereby forming the step. Here, the cross-sectional shapes of the first part and the second part are each circular. In the figure, the inner surface 26 located above is consistent with the first portion and the second portion, and the step 40 is formed by the deviation between the inner surface 25 located below and the inner surface 24. In the internal combustion engine 100 of this embodiment, as shown in FIG. 4 and the like, on one side of the upper part of the combustion chamber 10, an intake valve (lift valve) 14 for opening and closing the outlet 15 of the intake pipe 20 is provided. The direction in which the outlet 15 of the suction pipe 20 extends upstream (51) of the suction pipe 20 is a direction extending diagonally above the one side. Then, the inner surface 28 on the second end portion 3Ob side of the suction pipe 20 extends downstream (52) and reaches the center side of the upper portion of the combustion chamber 10. By constructing the suction pipe 20 in this manner, the rolling flow 55 can be formed relatively easily. In the present embodiment, the suction pipe 20 downstream (52) has a structure that is curved in a substantially arc shape and reaches the upper portion of the combustion chamber 10 compared with the throttle valve 30. 97469.doc -15- 200530495 Furthermore, on the other side of the upper part of the combustion chamber 10, there is an exhaust valve (lift valve) 16 and an exhaust pipe (exhaust port) is installed inside the exhaust valve 16 Μ. Ran Ting. The piston 丨 2 in the chamber 10 vibrates up and down to implement the various strokes of moving money and burning ^ ·. For the sake of convenience, the relationship between the figure and the work is used in the description. The internal combustion engine 100 of this embodiment is not arranged above or above the figure. The throttle valve 30 is designed to allow idling even when it is completely closed: the required air 50 passes, in other words, the throttle valve 30 can reduce the amount of air 50 introduced into the combustion chamber 10 to at most the idling station. Suction valve (butterfly valve) for necessary air volume. On the downstream (52) side of the throttle valve 30, a combustion injection valve (not shown) is provided. For the intake air (50b) flowing out of the throttle valve 30, the fuel injection valve injects fuel, thereby generating fuel A mixed gas, and the mixed gas forms a rolling flow 55 in the combustion chamber 10. Qe
再者，必需區別可降低至空轉所必需之空氣量之節流閥 3〇，與用以實現渦流增大之渦流控制閥（例如，參照曰本專 利實開平2.92G3G號公報）。即，其性f ±，雖然渦流控制閱 之周邊設有階差，但未必可實現滾動流（55)之形成的強化， 或滾動流（55)之控制。於汽車之渦流控制閥中，於某氣筒之 燃燒至吸入的吸氣量藉由其他節流閥得以控制，渦流控制 閥係僅發揮變更流之作用者。 本實施形態之内燃機1〇〇特別適用於自動二輪車用之弓 擎。其原因在於：於自動二輪車中，於單氣筒之情形時戌 或於複數個氣筒之情形時，多使用以丨個燃燒室為單位，努 氣管内設有1個以上之節流閥之引擎。即，於自動車之情开 夺例如於6個氣筒弓丨擎之情形時，對於集合吸氣通路（努 97469.doc -16- 200530495 氣口）之上游之部位設有1個節流闊者（例如，參照曰本專利 特開平5-240045號公報之圖1)，於自動二輪車之情形時，為 提高使吸氣閥（吸氣節流閥）動作時之響應，以1個燃燒室為 單位，設置1個以上之節流閥於吸氣管内。 於本實施形態之構成中，以燃燒室1 〇為單位獨立設置節 流閥30，且設置節流閥30於接近燃燒室1〇之處。與汽車相 比，藉由設置節流閥30於接近燃燒室1〇之處，可以較強之 W產生滾動流5 5於燃燒室1 〇内。另一方面，即使如汽車於 較退處於節流閥進行相同之動作，亦不會成為有利於燃燒 之流（滾動流之產生）。 此處省略自動二輪車之整體構成之說明，但於具有本實 施形態之内燃機100之自動二輪車中，藉由簡單之構成可產 生滾動流，以及調整滚動流之形成，因此可以低成本提供 引擎性能提高之自動二輪車。本申請案明細書中之所謂「自 動二輪車」是指摩托車之意，含有帶原動機之自行車（摩托 車）、小型摩托，具體而言，即為可使車體傾斜動作旋轉之 車輛。因此，將前輪以及後輪之至少一方設為2輪以上，輪 胎數之汁數即使為二輪車·四輪車（或其以上），其皆包含於 「自動二輪車」。 再者，並非侷限於自動二輪車’亦可適用於需要使吸氣 節流閥動作時之良好響應的其他車輛，例如，除自動二輪 車之外，亦可適用於所謂鞍乘型車輛（機動雪車、四輪小車 (ATV:A11 Terrain Vehicle(全地形型車輛））等）。又對於本 貫施形態之内燃機10 0 ’亦可適用閥可變機構。 97469.doc -17- 200530495 依據本發明之實施形態之内燃機丨00，於吸氣管20中之節 流閥（蝶式節流閥）30之上游（51)，設有階差4〇，該階差4〇係 與面向節流閥30之第1端部3(^之空氣流5〇a相比，加強面向 第2端部3Ob之空氣流50b者，因此於燃燒室1〇中，可產生更 明確之滚動流55。即，藉由簡單之構成，可於低負荷時較 谷易地產生滾動流5 5。又，於高負荷時，節流閥3 〇之開口 耘度變大，因此自第1端部3〇a附近之開口流出之空氣流5〇a 之S與自第2端部30b附近之開口流出之空氣流5〇b之量的 差自然變小，其結果係可調整滚動流55之形成。即，可形 成均一之流於燃燒至1 〇，可抑制燃燒效率之降低、或輸出 之降低、燃費之惡化等。因此，藉由本實施形態之内燃機 100 ’可以簡單之構成產生滾動流55，並且可調整滾動流η 之形成。 接著，參照圖6至圖8,關於本實施形態之内燃機1〇〇加以 進一步之詳細說明。圖6係模式性表示本實施形態之内燃機 100之構成之剖面圖，圖7係節流閥之周圍之主要部分之放 大圖。圖8係自沿著圖7中之線獨，之剖面所視之圖。 如圖6所#，内燃機1〇〇含有支撐未圖示之曲轴之曲轴 箱，以及自該曲軸箱突出之氣缸1〇2。於圖6中，為便於說 明’使該氣缸H)2内之氣缸孔1G3之軸心…為與㉟直線一致 之姿勢，側面視内燃機1 〇〇。 於氣缸孔103 ’沿軸方向以變化自由之方式嵌入活遽 1〇5,該活塞Η)5得以傳動連接於上述曲軸，將以氣缸舰 及活塞105所包圍之氣飯1〇2内之氣奴孔⑻之上部作為楚 97469.doc -18- 200530495 燒室106。 於氣缸102之上部’形成有吸氣通路1〇9，其使該氣缸1〇2 之一側方（面向圖6之右側方）之外部連通至燃燒室1〇6，以及 排氣通路110，其使燃燒室106與氣缸1〇2之其他侧方（面向 圖6之左側方）之外部連通。於向燃燒室1 〇6之吸氣通路1 〇9 以及排氣通路110之各開口，設有以可開關之方式關閉其各 開口之吸氣閥111以及排氣閥丨丨2。所謂該等吸氣閥丨丨丨以及 排氣閥112，藉由傳動於曲轴之動閥構造，可恰當進行開關 閥之動作。 於氣缸102中設有吸氣管115,其自氣缸ι〇2之上部向一側 方延伸。吸氣管115之内部成為吸氣通路（109、U6、129)， 大氣側通過吸氣通路（109等）連通至燃燒室1〇6。於吸氣通路 Π6配置有蝶式節流閥丨17，該節流閥以可開關之方式關閉 該吸氣通路116，該節流閥117呈圓板形狀。再者，於吸氣 通路116之縱方向之節流閥117之中途部藉由樞支軸丨丨8樞 支至形成吸氣通路116之構件之吸氣管115。 如圖7所不’郎流閥117可以槐支轴118之植支轴心119為 中心轉動。因此，節流閥117之一端部120側（圖3中之第2端 部30b侧）可向氣缸102内之燃燒室1〇6側（即，下游）來回轉動 (A ’ B) ’並且節流閥117之其他端部側12 1(圖3中之第1端部 3〇a側）可向自氣缸1〇2内之燃燒室ι〇6側離開之方向（即，上 游）來回轉動C，D。 若使節流閥117進行往轉動A，C，則節流閥117進行開閥 動作，吸氣通路116得以打開（參照圖7中之一點劃線117)。 97469.doc -19- 200530495 另一方面’若使節流閥117進行複轉動B，D，則節流閥117 進行關閥動作，吸氣通路116得以關閉（參照圖7中之實線 117)。 於比節流閥17下游側之吸氣通路1〇9，安裝有喷射供給燃 料124至燃料室1〇6之燃料供給機構（燃料喷射閥）125。即， 於氣缸102，介以吸氣通路109設置有燃料供給機構125。 又’於燃燒室106，以放電部露出之方式安裝有點火插塞 126 〇 於節流閥117之其他端部121之附近，設有階差40。於本 實施形態之構成中，藉由吸氣通路116之第1部分129與第2 部分131之偏差形成階差4〇。即，以内燃機ι〇〇之側面視（參 照圖7)，相對於吸氣通路116之第2部分ι31之剖面中心線 132，吸氣通路116之第1部分ι29之剖面中心線13〇偏移（亦 參照圖8)。 換έ之’相對於第2部分13 1之剖面中心線132，於吸氣通 路116之縱方向，第丨部份129之剖面中心線13〇偏向節流閥 11 7之一端部側120。又，第1部份129以及第2部份13 1之各 剖面形狀分別呈圓形。再者，第i部份129係與節流閥117附 近之該節流閥U7相比上游側之吸氣通路116之一部分，另 一方面，第2部分131係於比第1部分129下游側以接近該第J 部份129之方式而配置之部分。 又’於本實施形態之構成中，於吸氣通路116之長度方 向，使節流閥117之轉動軌跡138，以及作為自第1部分129 變化為第2部分13 1之部分的階差（換言之，變化部分）4〇之分 97469.doc -20- 200530495 別之至少一部分位於相互相同之位置。 如圖7所示之階差（變化部分）40為大致垂直於第i部分129 之剖面中心線130之面。因此，第！部份129與第2部分131於 吸氣通路116之長度方向以相互臨近之方式鄰接。然後，於 吸氣通路116之長度方向，使階差（變化部分）4〇之整體，以 及節流閥117之轉動執跡138之一部分位於相互相同之位 置。 另一方面，作為改變例圖7所示之階差（變化部分）4〇，係對 於第1部分129之剖面中心線130傾斜之傾斜面。即，階差4〇· 係自第1部分129向第2部分13 1側剖面積增大之圓錐台形 狀。因此，第1部分129以及第2部分131於吸氣通路116之長 度方向，夾著階差（變化部分）40,相互鄰接，且階差（變化部 分）40’以及轉動軌跡138之各一部分於吸氣通路116之長度 方向，位於相互相同之位置。 又，節流閥117之轉動軌跡138，以及第1部分129之分別 至少一部分139間於吸氣通路116之長度方向，位於相互相 同之位置，即，節流閥117以及第1部份129於吸氣通路U6 之長度方向’相互間得以更充分地接近。 如圖6所示，相比節流閥117更下游側之吸氣通路1〇9、116 之第3部分135，其剖面中心線136向上方呈凸形狀之圓弧形 狀，以此方式彎曲該第3部分135。更具體而言，第3部分135 一旦自燃燒室106侧向上方延伸後，向上方且向氣缸1〇2之 一側方延伸，隨著向該一側方延伸，該剖面中心線136之仰 角變小。 97469.doc -21 - 200530495 又，第3部分135之内面中之彎曲半徑較大侧（上面側），以 及節流閥11 7之一端部侧120於吸氣通路116之第3部分135 之縱方向，位於相互相同側。吸氣管11 5中，至少含有節流 閥117之吸氣管115之部分141得以鑄造，該吸氣管115之部 分141中，於吸氣管151之長度方向，藉由機械加工，僅上 述第2部份131之内面13 la得以成形，其位於與節流閥117大 致相同之位置，呈剖面圓形。 藉由本實施形態之構成，於相比該第1部分129之下游 侧’對於以接近該第1部分129之方式而配置的吸氣通路116 之第2部分131之剖面中心線132，於吸氣通路116之縱方 向’使比節流閥117上游側的吸氣通路116之第1部分129之 剖面中心線130偏向節流閥117之一端部侧120。 此處，於内燃機1 〇〇之運轉時，使節流閥n 7進行開閥動 作（圖6中一點劃線117)，打開吸氣通路丨〇9、116後，通過吸 氣通路109，116，吸入外部空氣143至氣缸102内。以上述 方式開閥動作之節流閥117之一端部側12〇向氣缸1〇2侧進 行往轉動A，因此於吸氣通路109，116内面向氣缸1〇2側流 動之空氣143内之較多者面向氣缸1〇2側通過節流閥開口 M4,該節流閥開口位於吸氣通路116之内周面與節流閥ιΐ7 之一端部側120之間。 並且，於節流閥117之附近形成有階差4〇(或4〇，），因此於 吸氣通路116之第1部分129面向節流閥i丨7侧流動之空氣 143得以更確實地面向節流閥開口 144側。換言之，於相比 。玄第1部分129下游側對於以接近該帛丨部分129之方式而配 97469.doc -22- 200530495 置的吸氣通路116之第2部分131之剖面中心線132，於吸氣 通路116之縱方向，使比節流閥U7上游侧的吸氣通路丨16之 第1部分129之剖面中心線130偏向節流閥117之一端部侧 120 ’因此可使於吸氣通路116之第i部份丨29面向節流閥117 側流動之空氣14 3更確實地面向節流閥開口 14 4側。 因此，通過節流閥開口 144向著氣缸1〇2内流動之空氣143 於吸氣通路109之縱方向，更確實地偏流向節流閥117之一 端部側120吸入至氣缸102内，因此吸入至該氣缸1〇2内之空 氣143與藉由燃料供給機構125所供給之燃料124—併設為 更明確之滾動流146。藉此，可獲得點火插塞126之良好著 火性，以及迅速之火焰傳播，其結果係可進一步提高引擎 性能。 又，如上所述，使第1部分129位於節流閥117之附近，因 此第1部份129越接近節流閥117，於第1部份129面向節流閥 117流動之空氣143得以更確實地面向節流閥開口 144側。 因此，通過節流閥開口 144面向氣缸102内之流動空氣143 於吸氣通路109之縱方向，得以更確實地偏流向節流閥11 7 之一端部側120，吸入至氣缸102内，因此吸入至該氣缸102 内之空氣143與藉由燃料供給機構125所供給之燃料124 — 併設為更明確之滾動流146，藉此可獲得點火插塞126之更 良好的著火性，以及更迅速之火焰傳播，可進一步提高引 擎性能。 又，如上所述，第1部分129以及第2部分131之各剖面形 狀分別為圓形，因此可抑制流動於第1部份129以及第2部分 97469.doc -23- 200530495 1 3 1之空氣143之壓力損失較小。因此，空氣143得以更強力 地吸入至氣缸102内，故而滾動流146為更明確者，可進一 步提高引擎性能。 又，如上所述’於吸氣通路116之長度方向，使節流閥ip 之轉動軌跡138,以及自第1部份129變化至第2部分131的部 分之階差（變化部分）40(或40，）之分別至少一部分位於相互 相同之位置’因此節流閥117與第1部分12 9於吸氣通路116 之長度方向可相互更確實地接近。因此，可立即使於吸氣 通路116之第1部分12 9向節流閥117側流動之空氣14 3面向 節流閥開口 144侧。 因此，通過節流閥開口 144向氣紅102内流動之空氣143 於吸氣通路109之縱方向，更確實地偏流向節流閥U7之一 端部側120，吸入至氣缸1 〇2内。因此滾動流146為更明確 者，引擎性能得以進一步提高。 又’如上所述，於吸氣通路116之長度方向，使節流閥117 之轉動執跡38，以及第1部份129之分別至少一部分139間位 於相互相同之位置，因此節流閥1丨7與第1部分129於吸氣通 路116之長度方向可相互更確實地接近。因此，可立即使於 吸氣通路116之第1部分129向上述節流閥117側流動之空氣 143更確實地面向上述節流閥開口 ι44側。 因此’通過節流閥開口 144向氣缸102内流動之空氣143 於吸氣通路109之縱方向，更確實地偏流向節流閥117之一 端部側120，吸入至氣缸1〇2内，因此滚動流146為更明確 者’引擎性能得以更為確實地提高。 97469.doc 200530495 又，如上所述，比節流閥117下游側之吸氣通路109，116 之第3部分135，以其剖面中心線136呈圓弧形狀之方式彎曲 該第3部分135，於吸氣通路109之第3部分135之縱方向，使 該第3部分135之内面中的彎曲半徑較大侧以及節流閥117 之一端部侧12 0位於相互相同側，因此藉由其慣性力，於吸 氣通路109之第3部分135之縱方向，使於吸氣通路1〇9之第3 部分135向氣缸102内流動之空氣143偏流向節流閥117之一 端部側120。另一方面，於吸氣通路1〇9之縱方向，通過節 流閥開口 144向氣缸102内流動於吸氣通路1〇9之空氣143亦 偏流向節流閥117之一端部側120，因此於上述吸氣通路1 〇9 之第3部分135中，以上述方式偏流之空氣143之偏流狀態進 一步得以助長。 因此，以上述方式偏流之空氣143得以吸入至氣缸1〇2内之 時，上述滾動流146為更明確者，引擎性能得以進一步提高。 又，如上所述，將内含節流閥117之吸氣管115之部分141 設為鑄造製，於該鑄造製之吸氣管U5之部分141中，於吸 氣通路116之長度方向，藉由機械加工僅成形第2部份131之 内面131a，其位於與節流閥117大致相同之位置。 因此，節流閥開口 144之吸氣通路1〇9之第2部分131之内 面變得平滑，因此通過節流閥開口 144之空氣143之流動變 得順利。因此，通過節流閥開口 144之空氣143於吸氣通路 109之縱方向’更確實地偏流向節流閥η 7之一端部側12〇， 引擎性能得以更為確實地提高。 又，於吸氣管115之部分141中，於吸氣通路116之長度方 97469.doc -25- 200530495 向，自節流閥117偏向之其它部分保持鑄造後之狀態即可， 因此可簡單地實現上述吸氣管115之部分141之構造或成形。 接著，參照圖9且就本實施形態之内燃機1〇〇之引擎性能 加以說明。圖9係表示使點火時期滞後角、超前角的各情形 時之引擎性能（燃料消耗率）之圖表。圖中之縱軸表示燃料消 耗率’橫軸表示點火時期。 圖9中之虛線（本發明）表示相當於上述本發明之實施形態 者。圖9中之細實線（比較例丨）表示於上述實施形態中，使吸 氣通路116之第1部分129以及第2部分131之各剖面中心線 130，132相互同軸，未形成階差4〇者。再者，圖9中之粗實 線（比較例2)表示與比較例丨同樣同軸，於吸氣通路ιΐ6未形 成階差40,使節流閥117(實線，一點劃線）之來回轉動之方 向為相反者（圖7中之二點劃線117·)之結果。即，比較例2係 使各❹中心線130’ 132相互同軸，且與上述實施形態相 反節/;,L閥117之一端部侧120,係可向著自氣缸丨〇2側離開 之方向來回轉動者（圖7中之二點劃線117，）。 以自圖9可理解之方式，藉由本發明之實施形態，可跨越 點火時期之較廣範圍，提高引擎性能。 圖10表示關於吸氣通路116之第i部分129以及第2部份 131的其他實施形態。藉此，第丨部分129之剖面整體呈圓 形其刀為直線形，藉此，使各剖面中心線130，132 相互偏向。再者，即使為同軸，亦可產生階差40,因此本 發明之方法並非侷限於同轴者。 又，如圖7所不之例中，可包含配置有節流閥117之吸氣 97469.doc 200530495 管之部分141的階差40(或40，），一併製造。gp，一旦製造部 分141後，無需藉由機械加工形成階 一、以口 亦可包含階差40 成型而形成。m含節流閥117之部分l4i作為第2部分 131 ’且形成第丨部分129作為上游側之吸氣管ιΐ5之一部 分’藉此亦可形成階差40。 再者，以上依據圖示之例加以說明，但氣缸孔ι〇3之軸心 1〇4亦可對於垂直線傾斜，亦可為大致水平。又，吸氣通路 109, 116—旦自燃燒室106侧向上方延伸後亦可向上方， 且向氣缸102之其它侧方延伸。又，若於低負荷時可良好地 形成滾動流146，則吸氣通路135亦可為筆直形狀者。 以上，藉由適當之實施形態說明本發明，但上述内容並 非為限定事項，當然可實行各種改變。 [產業上之可利用性] 藉由本發明，可提供一種内燃機，其可以簡單之構成產 生滾動流並可調整滾動流之形成。 【圖式簡單說明】 圖1係表示先前之内燃機之構成的剖面圖。 圖2係模式性表示本發明之實施形態的内燃機1 〇〇之構成 的剖面圖。 圖3(a)係節流閥之周邊的主要部分之放大剖面圖，且（b) 係沿著（a)中之線ΠΒ-1ΠΒ之剖面圖。 圖4係用以模式性說明本發明之實施形態之内燃機} 〇〇的 動作之圖。 圖5係用以模式性說明本發明之實施形態之内燃機100的 97469.doc -27- 200530495 動作之圖。 圖6係模式性表示本發明之實施形態之内燃機1⑼的構成 之剖面圖。 圖7係節流閥之周邊之主要部分的放大剖面圖。 圖8係沿著圖8中之線观_观之箭頭表示剖面圖。 圖9係表示使點火時期變化之情形時引擎性能之變化之 圖表。 圖1 〇係表示本發明之實施形態之内燃機丨〇〇之改變例的 構成之剖面圖。 【主要元件符號說明】 10 燃燒室 12 活塞 15 吸氣管之出口 16 排氣閥 17 節流閥 20 吸氣管 22 吸氣管之一部分（節2 24 ， 25 ， 26 吸氣管之内面 27 壁面 30 節流閥（蝶式節流閥） 30a 第1端部 30b 第2端部 31 樞支軸 38 轉動執跡 97469.doc -28- 200530495 40 階差 50 空氣 50a， 50b 空氣流 51 吸氣管之上游 52 吸氣管之下游 55 滾動流 100 内燃機 102 氣缸 103 氣缸孔 104 轴心 105 活塞 106 燃燒室 109， 116 吸氣通路 110 排氣通路 111 吸氣閥 112 排氣閥 115 吸氣管 116 吸氣通路 117 節流閥 118 樞支轴 119 樞支轴心 120 一端部 121 他端部 124 燃料 -29- 97469.doc 200530495 125 燃料供給機構 126 點火插塞 135 吸氣通路 138 轉動執跡 143 空氣 144 節流開口 146 滾動流 151 吸氣管 201 引擎 202 氣缸 207 氣缸頭部 209 活塞 211 燃燒室 212 吸氣通路 213 吸氣管 214 節流閥 216 燃料 217 燃料喷射閥 228 吸氣開口部 229 吸氣閥 246 放電部 250 空氣 251 混合氣 252 滾動流 97469.doc 30-Furthermore, it is necessary to distinguish between a throttle valve 30 that can reduce the amount of air necessary for idling, and a vortex control valve for increasing the vortex (for example, refer to Japanese Patent Kokkai 2.92G3G). That is, its characteristic f ±, although there is a step around the eddy current control, it is not always possible to strengthen the formation of the rolling flow (55) or control of the rolling flow (55). In the vortex control valve of an automobile, the amount of intake air from combustion to inhalation of a certain cylinder is controlled by other throttle valves. The vortex control valve system only plays a role of changing the flow. The internal combustion engine 100 of this embodiment is particularly suitable for a bow engine for a motorcycle. The reason is that in a two-wheeled motor vehicle, in the case of a single cylinder or in the case of a plurality of cylinders, an engine with more than one combustion valve in the air pipe is often used as a unit. That is, when the situation of an automatic car is deprived, for example, in the case of six air pump bows, one throttle is provided at the upstream part of the collection suction passage (nu 97469.doc -16- 200530495 air port) (for example, With reference to Figure 1 of Japanese Patent Laid-Open No. 5-240045, in the case of a motorcycle, in order to improve the response when the intake valve (intake throttle valve) is operated, one combustion chamber is used as a unit. Install more than one throttle valve in the suction pipe. In the configuration of this embodiment, the throttle valve 30 is independently provided in units of the combustion chamber 10, and the throttle valve 30 is provided near the combustion chamber 10. Compared with the automobile, by setting the throttle valve 30 close to the combustion chamber 10, it is possible to generate a rolling flow 55 which is stronger in the combustion chamber 10. On the other hand, even if the vehicle performs the same operation when the throttle is in the backward position, it will not become a flow that is conducive to combustion (generation of rolling flow). The description of the overall configuration of the motorcycle is omitted here. However, in a motorcycle having the internal combustion engine 100 of this embodiment, a simple structure can generate a rolling flow and adjust the formation of the rolling flow, so the engine performance can be provided at a low cost. Raised motorcycle. The so-called “autobicycle” in the specification of this application refers to the meaning of motorcycles, including bicycles (motorcycles) with a prime mover, and small motorcycles, specifically, vehicles that can tilt and rotate the car body. Therefore, if at least one of the front wheel and the rear wheel is set to be two or more wheels, even if the number of tires is a two-wheeled vehicle or a four-wheeled vehicle (or more), they are all included in the "automobile". Moreover, it is not limited to a two-wheeled vehicle. It can also be applied to other vehicles that require a good response when the intake throttle valve is actuated. For example, in addition to a two-wheeled vehicle, it can also be applied to a so-called saddle-type vehicle , Four-wheeled vehicles (ATV: A11 Terrain Vehicle). It is also possible to apply the valve variable mechanism to the internal combustion engine 10 0 ′ of the present embodiment. 97469.doc -17- 200530495 The internal combustion engine 00 according to the embodiment of the present invention is provided upstream of the throttle valve (butter throttle valve) 30 in the suction pipe 20 (51) with a step difference of 40. The step 40 is a step in which the air flow 50b facing the second end 3Ob is stronger than the air flow 50a facing the first end 3b of the throttle valve 30. Therefore, in the combustion chamber 10, the A more specific rolling flow 55 is generated. That is, with a simple structure, a rolling flow 5 5 can be generated more easily than a valley at low load. Also, at a high load, the opening of the throttle valve 3 0 becomes larger. Therefore, the difference between the amount of air flow S0a flowing from the opening near the first end portion 30a and the flow of air flowing 50b from the opening near the second end portion 30b naturally decreases, and the result is The formation of the rolling flow 55 can be adjusted. That is, a uniform flow can be formed to burn to 10, which can suppress a reduction in combustion efficiency, a decrease in output, a deterioration in fuel consumption, etc. Therefore, the internal combustion engine 100 ′ of this embodiment can The simple structure generates a rolling flow 55, and the formation of the rolling flow η can be adjusted. Next, referring to FIGS. 6 to 8, this embodiment is described. The internal combustion engine 100 is further described in detail. FIG. 6 is a cross-sectional view schematically showing the structure of the internal combustion engine 100 in this embodiment, and FIG. 7 is an enlarged view of the main part of the periphery of the throttle valve. Figure 7 is a view of the cross section of the line. As shown in # 6, the internal combustion engine 100 includes a crankcase supporting a crankshaft not shown, and a cylinder 102 protruding from the crankcase. In FIG. 6 In order to facilitate the explanation, 'Make the axis of the cylinder hole 1G3 in the cylinder H) 2 ... in a posture consistent with the straight line of the cylinder, the internal combustion engine 1 00 is viewed from the side. The cylinder bore 103 'is inserted into the cylinder 103 105 in a freely changing manner along the axial direction, and the piston Η) 5 can be driven and connected to the above-mentioned crankshaft, and the gas in the cylinder 102 surrounded by the cylinder ship and the piston 105 The upper part of the slave hole is Chu 97469.doc -18- 200530495 burning chamber 106. An air intake passage 10 is formed at the upper portion of the cylinder 102, which communicates the outside of one side (facing the right side of FIG. 6) of the cylinder 102 with the combustion chamber 106 and the exhaust passage 110, It communicates the combustion chamber 106 with the outside of the other side of the cylinder 102 (facing the left side of FIG. 6). An intake valve 111 and an exhaust valve 丨 2 are provided at each opening of the intake passage 1 10 and the exhaust passage 110 to the combustion chamber 1 06 to close the openings in a switchable manner. The so-called suction valves 丨 丨 丨 and exhaust valves 112 can be appropriately opened and closed by the structure of a moving valve that is driven by the crankshaft. An air suction pipe 115 is provided in the air cylinder 102, and extends from the upper part of the air cylinder 102 to one side. The inside of the intake pipe 115 becomes an intake passage (109, U6, 129), and the atmosphere side communicates with the combustion chamber 106 via the intake passage (109, etc.). A butterfly throttle 17 is provided in the suction passage Π6. The throttle valve closes the suction passage 116 in a switchable manner, and the throttle valve 117 has a circular plate shape. Further, the middle part of the throttle valve 117 in the longitudinal direction of the suction passage 116 is pivotally supported to the suction pipe 115 forming a component of the suction passage 116 via a pivot support shaft 丨 8. As shown in FIG. 7, the Lang flow valve 117 can be rotated around the planting support shaft center 119 of the support shaft 118. Therefore, one end portion 120 side (the second end portion 30b side in FIG. 3) of the throttle valve 117 can be turned back and forth (A'B) 'toward the combustion chamber 106 side (ie, downstream) in the cylinder 102 and The other end side 12 1 of the flow valve 117 (the first end 30 a side in FIG. 3) can rotate back and forth in a direction (ie, upstream) from the combustion chamber ι 06 side in the cylinder 102 , D. When the throttle valve 117 is rotated A and C, the throttle valve 117 is opened and the intake passage 116 is opened (refer to a one-dot chain line 117 in FIG. 7). 97469.doc -19- 200530495 On the other hand, if the throttle valve 117 is repeatedly rotated B, D, the throttle valve 117 performs a valve closing operation, and the suction passage 116 is closed (see a solid line 117 in FIG. 7). A fuel supply mechanism (fuel injection valve) 125 that injects and supplies fuel 124 to the fuel chamber 106 is installed in the intake path 109 downstream of the throttle valve 17. That is, the cylinder 102 is provided with a fuel supply mechanism 125 via an intake passage 109. Further, an ignition plug 126 is attached to the combustion chamber 106 so that the discharge portion is exposed. A step 40 is provided near the other end portion 121 of the throttle valve 117. In the configuration of this embodiment, a step difference of 40 is formed by the deviation between the first portion 129 and the second portion 131 of the intake passage 116. That is, the side view of the internal combustion engine ιOO (see FIG. 7) is offset from the centerline 132 of the cross section of the second part ι31 of the intake path 116, and the centerline 13 of the cross section of the first part ι29 of the intake path 116 (See also Figure 8). In other words, with respect to the section center line 132 of the second section 13 1, in the longitudinal direction of the suction path 116, the section center line 13 of the section 129 is biased toward one end 120 of the throttle valve 11 7. The cross-sectional shapes of the first portion 129 and the second portion 131 are each circular. In addition, the i-th part 129 is a part of the intake passage 116 on the upstream side of the throttle valve U7 near the throttle 117, and the second part 131 is on the downstream side of the first part 129 A portion arranged in a manner close to the J-part 129. In addition, in the configuration of this embodiment, the trajectory 138 of the throttle valve 117 in the length direction of the suction passage 116 and the step difference which is a portion changed from the first portion 129 to the second portion 131 (in other words, Change part) 40 points 97469.doc -20- 200530495 At least part of the others are located at the same position with each other. The step (change portion) 40 shown in FIG. 7 is a surface that is approximately perpendicular to the cross-section center line 130 of the i-th portion 129. So No.! The portion 129 and the second portion 131 are adjacent to each other in the length direction of the suction path 116. Then, in the length direction of the suction path 116, the entire step (change portion) 40 and a part of the rotation track 138 of the throttle valve 117 are located at the same position with each other. On the other hand, as a modified example, the step (change portion) 40 shown in FIG. 7 is an inclined surface inclined with respect to the center line 130 of the cross section of the first portion 129. That is, the step difference 40 · is a truncated cone shape whose cross-sectional area increases from the first portion 129 to the second portion 13 1 side. Therefore, the first portion 129 and the second portion 131 are adjacent to each other with the step (change portion) 40 sandwiched in the length direction of the suction path 116, and each of the step (change portion) 40 'and the rotation track 138 is at The length directions of the suction passages 116 are located at the same positions as each other. In addition, the rotation trajectory 138 of the throttle valve 117 and at least a portion 139 of the first portion 129 are located at the same position with each other in the length direction of the suction path 116, that is, the throttle valve 117 and the first portion 129 are at the same position. The length directions of the suction passages U6 are more fully approached to each other. As shown in FIG. 6, the third portion 135 of the suction passages 10 and 116 on the downstream side of the throttle valve 117 has a convex arc shape in the center of the cross section 136 upward. Part 3 135. More specifically, once the third portion 135 extends upward from the combustion chamber 106 side, it extends upward and one side of the cylinder 102, and as it extends toward the one side, the elevation angle of the centerline 136 of the section Get smaller. 97469.doc -21-200530495 In addition, the side with the larger bending radius (upper side) in the inner surface of the third part 135 and the longitudinal side of one end 120 of the throttle valve 11 7 in the third part 135 of the suction passage 116 The directions are on the same side as each other. In the suction pipe 115, a part 141 of the suction pipe 115 including at least the throttle valve 117 is cast. Among the suction pipe 115, the part 141 is machined in the length direction of the suction pipe 151. The inner surface 13 a of the second portion 131 is formed, and is located at the same position as the throttle valve 117 and has a circular cross section. With the configuration of this embodiment, the cross-section centerline 132 of the second portion 131 of the suction passage 116 arranged near the first portion 129 on the downstream side of the first portion 129 is closer to the first portion 129. The longitudinal direction of the passage 116 is offset from the center line 130 of the cross section of the first portion 129 of the intake passage 116 on the upstream side of the throttle valve 117 toward one end portion 120 of the throttle valve 117. Here, during the operation of the internal combustion engine 100, the throttle valve n 7 is opened (dotted chain line 117 in FIG. 6), the intake passages 9 and 116 are opened, and then the intake passages 109 and 116 are passed. The outside air 143 is sucked into the cylinder 102. One end of the throttle valve 117, which operates in the manner described above, rotates 120 toward the cylinder 102 side of the throttle valve 117. Therefore, the air flow in the intake passages 109 and 116 facing the cylinder 102 side is relatively small. Many of them pass through the throttle valve opening M4 facing the 102 side of the cylinder, and the throttle valve opening is located between the inner peripheral surface of the intake passage 116 and one end side 120 of the throttle valve ΐ7. In addition, a step difference of 40 (or 40 °) is formed near the throttle valve 117, so that the air 143 flowing in the first part 129 of the intake passage 116 facing the throttle valve i7 can face more surely. Throttle valve opening 144 side. In other words, compared to. On the downstream side of the first part 129, the center line 132 of the cross section of the second part 131 of the inhalation passage 116 provided with the 97469.doc -22- 200530495 in a manner close to the part 129 is in the longitudinal direction of the inhalation passage 116. Direction, so that the cross section center line 130 of the first part 129 of the intake passage 16 on the upstream side of the throttle valve U7 is biased toward one end portion 120 of the throttle valve 117, so that it can be used for the i-th part of the intake passage 116 The air 14 3 flowing toward the throttle valve 117 side faces the throttle valve opening 14 4 side more surely. Therefore, the air 143 flowing toward the cylinder 102 through the throttle valve opening 144 is drawn in the longitudinal direction of the suction passage 109, and is more surely deflected toward the one end portion 120 of the throttle valve 117 and sucked into the cylinder 102. The air 143 in the cylinder 102 and the fuel 124 supplied by the fuel supply mechanism 125 are set to a more specific rolling flow 146. Thereby, good ignition properties of the ignition plug 126 and rapid flame propagation can be obtained, and as a result, engine performance can be further improved. As described above, since the first portion 129 is located near the throttle valve 117, the closer the first portion 129 is to the throttle valve 117, the more accurately the air 143 flowing in the first portion 129 faces the throttle valve 117. The ground faces the throttle opening 144 side. Therefore, the flow air 143 facing the cylinder 102 through the throttle valve opening 144 in the longitudinal direction of the suction passage 109 can be more surely deflected toward the one end portion 120 of the throttle valve 11 7 and sucked into the cylinder 102. The air 143 in the cylinder 102 and the fuel 124 supplied by the fuel supply mechanism 125 are set to a more specific rolling flow 146, thereby obtaining a better ignition quality of the ignition plug 126 and a faster flame. Propagation can further improve engine performance. In addition, as described above, the cross-sectional shapes of the first part 129 and the second part 131 are respectively circular, so the air flowing in the first part 129 and the second part 97469.doc -23- 200530495 1 3 1 can be suppressed. The pressure loss of 143 is small. Therefore, the air 143 can be more strongly sucked into the cylinder 102, so the rolling flow 146 is more specific, which can further improve the engine performance. In addition, as described above, in the length direction of the suction path 116, the rotation trajectory 138 of the throttle valve ip and the step (change portion) 40 (or 40) of the portion that changes from the first portion 129 to the second portion 131 At least part of them are located at the same position with each other ', therefore, the throttle valve 117 and the first portion 129 can be more reliably approached to each other in the length direction of the suction path 116. Therefore, the air 14 3 flowing toward the throttle valve 117 side of the first portion 12 9 of the suction passage 116 can be immediately faced to the throttle valve opening 144 side. Therefore, the air 143 flowing into the gas red 102 through the throttle valve opening 144 in the longitudinal direction of the suction passage 109 is more surely deflected toward one end side 120 of the throttle valve U7 and sucked into the cylinder 102. Therefore, the rolling flow 146 is more specific, and the engine performance is further improved. As described above, in the length direction of the suction passage 116, the rotation track 38 of the throttle valve 117 and at least a portion 139 of the first portion 129 are located at the same position with each other, so the throttle valve 1 丨 7 The longitudinal direction of the first portion 129 and the suction path 116 can be more reliably approached to each other. Therefore, the air 143 flowing in the first portion 129 of the intake passage 116 toward the throttle valve 117 side can be more surely faced to the throttle valve opening 44 side. Therefore, the air 143 flowing into the cylinder 102 through the throttle valve opening 144 in the longitudinal direction of the suction passage 109 is more surely deflected toward one end 120 of the throttle valve 117 and sucked into the cylinder 102, so it rolls Motive flow 146 is more specific, and the engine performance is more surely improved. 97469.doc 200530495 As described above, the third portion 135 of the suction passages 109 and 116 on the downstream side of the throttle valve 117 is curved so that the center line 136 of the cross section is in an arc shape. The longitudinal direction of the third portion 135 of the suction passage 109 is such that the side with the larger bending radius in the inner surface of the third portion 135 and the end side 1 2 of the throttle valve 117 are located on the same side with each other. In the longitudinal direction of the third portion 135 of the intake passage 109, the air 143 flowing into the cylinder 102 of the third portion 135 of the intake passage 109 is deflected toward one end side 120 of the throttle valve 117. On the other hand, in the longitudinal direction of the intake passage 109, the air 143 flowing in the intake passage 109 through the throttle opening 144 into the cylinder 102 also deflects toward one end side 120 of the throttle 117, so In the third part 135 of the above-mentioned suction passage 1009, the biased state of the air 143 biased in the above manner is further promoted. Therefore, when the biased air 143 is sucked into the cylinder 102, the rolling flow 146 is more specific, and the engine performance is further improved. As described above, the portion 141 of the suction pipe 115 containing the throttle valve 117 is made of casting. In the portion 141 of the casting suction pipe U5, the length of the suction passage 116 is borrowed. Only the inner surface 131 a of the second portion 131 is formed by machining, and is located at substantially the same position as the throttle valve 117. Therefore, the inner surface of the second portion 131 of the intake passage 109 of the throttle valve opening 144 becomes smooth, so that the flow of air 143 through the throttle valve opening 144 becomes smooth. Therefore, the air 143 passing through the throttle valve opening 144 in the longitudinal direction ′ of the intake passage 109 is more surely deflected toward one end portion 12 of the throttle valve η 7, and the engine performance is more surely improved. In addition, in the part 141 of the suction pipe 115, the length of the suction passage 116 is 97469.doc -25- 200530495, and the other parts biased from the throttle valve 117 can be kept in a cast state, so it can be simply The structure or forming of the part 141 of the above suction pipe 115 is realized. Next, the engine performance of the internal combustion engine 100 of this embodiment will be described with reference to Fig. 9. Fig. 9 is a graph showing engine performance (fuel consumption rate) when the ignition timing is retarded and advanced. In the figure, the vertical axis represents the fuel consumption rate 'and the horizontal axis represents the ignition timing. The dashed line (the present invention) in Fig. 9 represents the embodiment corresponding to the above-mentioned embodiment of the present invention. The thin solid line (comparative example 丨) in FIG. 9 shows that in the above embodiment, the center lines 130 and 132 of the cross sections of the first portion 129 and the second portion 131 of the suction passage 116 are coaxial with each other, and no step 4 is formed. 〇 者. In addition, the thick solid line (Comparative Example 2) in FIG. 9 shows the same coaxiality as Comparative Example 丨, and no step 40 is formed in the suction path ιΐ6, so that the throttle valve 117 (solid line, one-dot chain line) is turned back and forth The direction is the result of the opposite (two-dot chain line 117 · in Fig. 7). That is, in Comparative Example 2, the center lines 130 ′ 132 of each cymbal are coaxial with each other, and are opposite to the above-mentioned embodiment. The one end side 120 of the L valve 117 can rotate back and forth in a direction away from the cylinder (The two-dot chain line 117 in FIG. 7). In a manner that can be understood from FIG. 9, with the embodiment of the present invention, the engine performance can be improved over a wide range of ignition periods. FIG. 10 shows another embodiment of the i-th part 129 and the second part 131 of the suction passage 116. As shown in FIG. Thereby, the cross section of the first section 129 is rounded, and the blades are linear, whereby the center lines 130, 132 of the cross sections are biased toward each other. Moreover, even if it is coaxial, a step difference of 40 can be generated. Therefore, the method of the present invention is not limited to a coaxial one. Also, as shown in the example shown in FIG. 7, a step 40 (or 40 °) of the portion 141 of the suction 97469.doc 200530495 pipe equipped with the throttle valve 117 may be included and manufactured together. gp, once the part 141 is manufactured, it is not necessary to form the step by machining, and it can also be formed by including the step 40. The part 14i including the throttle valve 117 is used as the second part 131 'and the part 129 is formed as a part of the intake pipe 5 on the upstream side', thereby forming the step 40. The above description is based on the example shown in the figure, but the axis 104 of the cylinder hole ι03 may be inclined to a vertical line or may be substantially horizontal. In addition, the intake passages 109, 116 may extend upward from the combustion chamber 106 side once, and extend to the other side of the cylinder 102. If the rolling flow 146 can be formed well at a low load, the suction passage 135 may be a straight one. As mentioned above, the present invention has been described using appropriate embodiments, but the above is not a limitation, and various changes can be implemented. [Industrial Applicability] According to the present invention, it is possible to provide an internal combustion engine which can be simply configured to generate a rolling flow and can adjust the formation of the rolling flow. [Brief Description of the Drawings] Fig. 1 is a sectional view showing the structure of a conventional internal combustion engine. Fig. 2 is a sectional view schematically showing the configuration of an internal combustion engine 1000 according to the embodiment of the present invention. Fig. 3 (a) is an enlarged cross-sectional view of the main part of the periphery of the throttle valve, and (b) is a cross-sectional view along the line IIB-1IIB in (a). FIG. 4 is a diagram for schematically explaining the operation of the internal combustion engine in the embodiment of the present invention. FIG. 5 is a diagram for schematically explaining the operation of 97469.doc -27- 200530495 of the internal combustion engine 100 according to the embodiment of the present invention. Fig. 6 is a sectional view schematically showing the configuration of an internal combustion engine 1 内燃机 according to the embodiment of the present invention. Fig. 7 is an enlarged sectional view of a main part of the periphery of the throttle valve. FIG. 8 is a cross-sectional view taken along the line view of the arrow in FIG. 8. Fig. 9 is a graph showing changes in engine performance when the ignition timing is changed. FIG. 10 is a cross-sectional view showing the configuration of a modified example of the internal combustion engine according to the embodiment of the present invention. [Description of main component symbols] 10 Combustion chamber 12 Piston 15 Outlet of suction pipe 16 Exhaust valve 17 Throttle valve 20 Suction pipe 22 Part of the suction pipe (section 2 24, 25, 26 Inner surface of the suction pipe 27 Wall surface 30 Throttle (Butterfly Throttle) 30a 1st end 30b 2nd end 31 Pivot 38 Rotation position 97469.doc -28- 200530495 40 Step 50 Air 50a, 50b Air flow 51 Suction tube Upstream 52 Downstream of suction pipe 55 Rolling flow 100 Internal combustion engine 102 Cylinder 103 Cylinder bore 104 Shaft center 105 Piston 106 Combustion chamber 109, 116 Suction passage 110 Exhaust passage 111 Suction valve 112 Exhaust valve 115 Suction pipe 116 Suction Air passage 117 Throttle valve 118 Pivot shaft 119 Pivot shaft 120 One end portion 121 Other end portion 124 Fuel-29- 97469.doc 200530495 125 Fuel supply mechanism 126 Ignition plug 135 Intake path 138 Turning track 143 Air 144 Throttle opening 146 Rolling flow 151 Suction tube 201 Engine 202 Cylinder 207 Cylinder head 209 Piston 211 Combustion chamber 212 Intake passage 213 Intake tube 214 knots The fuel injection valve 216 217 a fuel intake valve 228 opening the intake valve 246 and discharge portion 229 250 251 air mixed gas stream 252 rolling 97469.doc 30-