1237674 攻、發明說明： 【發明所屬之技術領域】 本發明係關於一種用於内燃機之排氣循環系統，更特定 言之，本發明係關於一種EGR(排氣循環）排出管之安裝結 構，該EGR排出管用於自引擎排氣系統排出排氣並使其作 爲EGR氣體來循環入或返回該進氣系統。 【先前技術】 =於内燃機之排氣循環系統中應用的EGR(排氣循環）排 出+管結構在日本特許公開專利申請案第4_175449(,449)號 及第2002-180912 (，9 12)號中有所描述。 449之排軋循環系統使用一 EGR排出管且配置有一冷卻 器，其中該EGR排出管自安震於引擎排氣系統令之觸媒轉 化益的下游排出排氣並使其循環入進氣系、统，而冷卻器則 利用引擎冷卻劑冷卻（提取熱氣）職排出管以冷卻EGR氣 ^在912之使用了 —相似㈣排出f之排氣循環系統中， ，氣歧管藉由-法蘭附著至主引擎單元，而咖排出管則 糟由一獨立法蘭(形成於與最初提及的法蘭相同的表面上） 連接至該主引擎單元。 種類型之排氣循環系統中’由於該咖排出管需經 的振動’所以其較佳具有盡可能高的剛性。此外， 氣系統的可利用空間有限，因此爲安裝該腦排出 s 4擇之位置應較佳爲可節省空間的適合位置。然而，· 上文所引料文獻對此等要點上並無記載。 … 此外’用於安裝該EGR排㈣的可制空間限制於引擎1237674 Description of attack and invention: [Technical field to which the invention belongs] The present invention relates to an exhaust gas circulation system for an internal combustion engine. More specifically, the present invention relates to a mounting structure of an EGR (exhaust gas circulation) exhaust pipe. The EGR exhaust pipe is used to exhaust the exhaust gas from the engine exhaust system and make it circulate into or return to the intake system as EGR gas. [Prior art] = EGR (exhaust gas circulation) exhaust + pipe structure applied in the exhaust gas circulation system of internal combustion engines is disclosed in Japanese Patent Laid-Open Patent Application Nos. 4_175449 (, 449) and 2002-180912 (, 9 12) Described in. The exhaust rolling system of 449 uses an EGR exhaust pipe and is equipped with a cooler, wherein the EGR exhaust pipe discharges exhaust gas from the downstream of the engine exhaust system, which is activated by the engine exhaust system, and circulates it into the intake system. The cooler uses engine coolant to cool (extract hot air) the exhaust pipe to cool the EGR gas. ^ Used in 912-similar to the exhaust circulation system of exhaust f, the gas manifold is attached by a flange. To the main engine unit, and the coffee discharge pipe is connected to the main engine unit by a separate flange (formed on the same surface as the flange mentioned initially). In this type of exhaust gas circulation system, it is preferred to have as high rigidity as possible due to the vibration that the coffee discharge pipe must undergo. In addition, the available space of the air system is limited, so the location chosen for installing the brain drain should be a suitable space-saving location. However, these points are not documented in the cited literature. … In addition, the space available for installing the EGR exhaust is limited to the engine
O:\9I\91472.DOC 1237674 之安裝有acg(交流發電機）、空氣調節器壓縮機及其它此等 辅助裝置的-相彳’而且，此等輔助裝置易受egr排出管所 散發出的熱量影響1然亦應重視該等考慮事項，但是上 文所引用的文獻對此等要點亦無記栽。 疋 另外，在此種類型之排氣循環系統中，由於因需經受引 擎的振動所以該EGR排出管應較佳具有盡可能高的剛性之 事實及在引擎運行期間該EGR排出f會被加熱至高溫之事 :’因此應較佳採取一些方法以自該腿排出管驅散熱 置。然而，上文所引用的文獻對此等要點亦無記载。 【發明内容】 因此，本發明之一目的係藉由提供一種用於内燃機之排 氣循環系統以解決前述缺點，該排氣循環系統之特徵在 於：增大了用於排出及循環EGR氣體的EGR排出管之剛性 及藉由適當選擇EGR排出管之安裝位置來保存排氣系統空 間。 本t明之另一目的係提供一種用於内燃機之排氣循環系 統，其中EGR排出管不會對辅助裝置安裝空間造成限制且 減小了自EGR排出管所散發出的熱量對輔助裝置的影響。 本發明之又另一目的係提供一種用於内燃機之排氣循環 /τ'統’其特徵在於：增大了 EGr排出管的剛性，並可驅散 EGR排出管的熱量。 爲達成此等目的’本發明提供一種用於内燃機之排氣循 J衣系統，其具有一連接至引擎之排氣系統的氣體排出管， 5玄排氣系統包括一位於觸媒轉化器下游之位置、用於排出O: \ 9I \ 91472.DOC 1237674-acq (alternator), air conditioner compressor, and other such auxiliary devices are installed-moreover, these auxiliary devices are susceptible to emission from the egr discharge pipe These considerations should also be taken into account, but the literature cited above does not remember these points.疋 In addition, in this type of exhaust gas circulation system, the EGR exhaust pipe should preferably have as high rigidity as possible due to the vibration of the engine, and the EGR exhaust f will be heated to High temperature matters: 'Therefore, it is better to take some methods to expel the tube from the leg to dissipate heat. However, these points are not documented in the literature cited above. [Summary of the Invention] Therefore, an object of the present invention is to solve the aforementioned disadvantages by providing an exhaust gas circulation system for an internal combustion engine, which is characterized in that EGR for exhausting and circulating EGR gas is increased The rigidity of the exhaust pipe and the space of the exhaust system are saved by properly selecting the installation position of the EGR exhaust pipe. Another object of the present invention is to provide an exhaust gas circulation system for an internal combustion engine, in which the EGR exhaust pipe does not restrict the installation space of the auxiliary device and reduces the influence of the heat emitted from the EGR exhaust pipe on the auxiliary device. Yet another object of the present invention is to provide an exhaust gas circulation / τ ′ system for an internal combustion engine, which is characterized by increasing the rigidity of the Egr exhaust pipe and dissipating the heat of the EGR exhaust pipe. To achieve these objectives, the present invention provides an exhaust gas circulation system for an internal combustion engine, which has a gas exhaust pipe connected to the exhaust system of the engine. The exhaust system includes a downstream of a catalyst converter. Location, for discharge
O:\91\91472.DOC 1237674 :該=在生:排一至引擎之進氣系統的排氣導 將其連接至g .在將顧μ統之排氣導管彎曲的同時 氣導:==器之下游端;且將氣 ::之弓曲所朝向的一側上連接至該排氣導管。 L只施方式】 一實施例的用於 現將參照所附圖式來解釋根據本發明之 内燃機之排氣循環系統。 係-透視圖’展示-根據本發明之—實施例的安裝於 車輕内的心内燃機之排氣循環㈣，圖2係—透視圖，展 不该安裝於引擎上的排氣循環系統，及圖3係一透視圖，亦 顯不-排氣歧管谓圖3中所示的排氣循環系統之—部 刀的口Ρ分剖視圖，及圖5係其側視圖。 圖式中的數字10標示-内燃機引擎。該引擎10係火花點 火直列式、4缸、4循環（cycie) s〇HC引擎，其安裝於車 輛12的引擎艙12a内而相對於車輛長度方向呈橫向放置。 圖2所示ACG(父流發電機）14與（未圖示空氣調節裝 置之）一壓縮機16安裝於引擎1〇附近。該等辅助裝置由引擎 10驅動。爲了簡化圖式，在圖丨中省略了除引擎之外的其 他兀件，且圖1及其它圖中僅示意地表示了引擎1〇。 在引擎1 〇中，藉由空氣淨化器（未圖示）導入的空氣流過 進氣導管（未圖示），並在節流閥（未圖示）的調節下，穿過進 氣歧管進入個別氣缸的進氣端（未圖示）。（在圖1中，其上安 裝有進氣導管、進氣歧管及其類似物之進氣側係以參考數 字18標示。）O: \ 91 \ 91472.DOC 1237674: This = in the row: the exhaust guide of the air intake system of the engine is connected to g. When the exhaust pipe of the Gu system is bent, the air guide: == device The downstream end; and connect the air: on the side facing the bow of the gas :: to the exhaust duct. L-only mode] An embodiment of the present invention will now be explained with reference to the accompanying drawings for an exhaust gas circulation system of an internal combustion engine according to the present invention. System-perspective view 'shows-according to the present invention-an embodiment of an exhaust gas cycle of a core internal combustion engine installed in a vehicle light, Fig. 2 is a perspective view showing an exhaust gas circulation system that should not be installed on an engine, and FIG. 3 is a perspective view, which also shows that the exhaust manifold refers to the section P of the exhaust knife of the exhaust circulation system shown in FIG. 3, and FIG. 5 is a side view thereof. The number 10 in the figure indicates the internal combustion engine. This engine 10 is a spark-ignition in-line, 4-cylinder, 4-cycle SOCHC engine. It is installed in the engine compartment 12a of the vehicle 12 and is placed laterally with respect to the length of the vehicle. An ACG (parent flow generator) 14 and a compressor 16 (not shown in the air-conditioning apparatus) shown in Fig. 2 are installed near the engine 10. The auxiliary devices are driven by the engine 10. In order to simplify the drawing, other elements other than the engine are omitted in FIG. 丨, and FIG. 1 and other figures only schematically show the engine 10. In the engine 10, air introduced through an air cleaner (not shown) flows through an intake duct (not shown) and passes through an intake manifold under the adjustment of a throttle valve (not shown). Enter the intake end of an individual cylinder (not shown). (In Figure 1, the intake side on which the intake duct, intake manifold, and the like are mounted is indicated by reference numeral 18.)
O:\9I\9I472.DOC 1237674 在每個氣缸中，導入之空氣與從喷射器喷射入的汽油燃 料相混合以產生空氣-汽油燃料之混合物，在打開進氣閥（未 圖示）時，該混合物流入一燃燒室，其^該混合物點火並燃 燒。當排氣閥（未圖示）打開時，燃燒所得的氣體（排氣）流入 排氣歧管20。該排氣藉由安裝於排氣歧管2〇下游（正下方） 的觸媒轉化器22淨化，並隨後經由排氣導管24排放至外部。 如圖3中最佳地顯示，該排氣歧管20在其上（上游）埠形成 有一法蘭20a及，如圖2所示，藉由該法蘭20a附著至引擎1〇 之主單元10a(更精確地說，係氣缸蓋）上。詳言之，如圖3 所示’藉由使螺栓26穿過形成於法蘭20a内的孔及一插入墊 圈30並將螺栓26擰入形成於主引擎單元1〇a之氣缸蓋一側 面上的螺栓插入孔（未圖示），來附著該排氣歧管20。 如圖5中最佳地顯示，於包括引擎1〇之排氣歧管2〇及排氣 導苔24之排氣系統中提供的觸媒轉化器22包含一圓柱形殼 體22a及密封於圓柱形殼體22a中的催化床層22b。該催化床 層22b由三效催化劑組成。 在催化床層22b與圓柱形殼體22a之内壁之間插入熱絕緣 材料（未圖示），以用於在引擎10啓動時促進催化床層22b之 加熱。如圖3及4所示，使用一托架2仏將該圓柱形殼體22a 拴接至主引擎單元10a。雖然在圖中省略了細節，托架22c 系烊接於圓柱幵》设體22a之後表面，且藉由使螺检％穿過形 成於托架22c内之孔且將其擰入形成於主引擎單元l〇a之側 面内的螺栓插入孔，來將觸媒轉化器22固定於主引擎單元 l〇a。O: \ 9I \ 9I472.DOC 1237674 In each cylinder, the introduced air is mixed with the gasoline fuel injected from the injector to produce an air-gasoline fuel mixture. When the intake valve (not shown) is opened, The mixture flows into a combustion chamber, which ignites and burns. When the exhaust valve (not shown) is opened, the combustion gas (exhaust) flows into the exhaust manifold 20. The exhaust gas is purified by a catalyst converter 22 installed downstream (directly below) of the exhaust manifold 20 and then discharged to the outside through an exhaust pipe 24. As best shown in FIG. 3, the exhaust manifold 20 has a flange 20a formed on the upper (upstream) port thereof, and as shown in FIG. 2, the flange 20a is attached to the main unit 10a of the engine 10 (More precisely, the cylinder head). In detail, as shown in FIG. 3 ', by passing the bolt 26 through a hole formed in the flange 20a and an insert washer 30, and screwing the bolt 26 into the side surface of the cylinder head of the main engine unit 10a The bolts are inserted into holes (not shown) to attach the exhaust manifold 20. As best shown in FIG. 5, the catalytic converter 22 provided in the exhaust system including the exhaust manifold 20 of the engine 10 and the exhaust guide 24 includes a cylindrical casing 22 a and sealed in a cylindrical shape. The catalyst bed 22b in the shell 22a. The catalyst bed 22b is composed of a three-way catalyst. A thermal insulation material (not shown) is inserted between the catalytic bed 22b and the inner wall of the cylindrical casing 22a to facilitate the heating of the catalytic bed 22b when the engine 10 is started. As shown in FIGS. 3 and 4, the bracket 22a is used to bolt the cylindrical casing 22a to the main engine unit 10a. Although the details are omitted in the figure, the bracket 22c is connected to the rear surface of the cylindrical body 22a, and is formed on the main engine by passing the screw inspection through the hole formed in the bracket 22c and screwing it in. Bolt insertion holes in the side surfaces of the unit 10a are used to fix the catalyst converter 22 to the main engine unit 10a.
O:\9J\9 U72.DOC 1237674 排氣‘ g 24連接於觸媒轉化器22之圓柱形殼體的下 游端。該排氣導管24形成有直徑從觸媒轉化器22正下方開 始逐步減少的錐形部分24a。如圖2中最佳地顯#，將排氣 導管24組態成彎曲形狀以逐漸移離辅助裝置，例如agc μ 及空氣調節器壓縮機16。該排氣導管24藉由法蘭24b與一更 T游的排氣導管（未圖示）相連接。 將EGR排出管（氣體排出管）32連接至排氣導管以的錐形 部分24a以排出排氣並將其作爲EGR氣體循環至進氣系 統，忒進氣系統包括進氣導管及位於進氣側1 8的引擎1 〇之 進亂歧官。具體言之，該EGR排出管32插入一形成於錐形 部分24a内的之孔，並藉由焊接固定於該位置。因此在將該 排氣導官24彎曲的同時將其與觸媒轉化器22相連接（以彎 曲形式）’且將EGR排出管32連接至排氣導管24之彎曲所朝 向的側上。此外，將該EGr排出管32在與agc 14及類似裝 置相對的觸媒轉化器22之側面上與該觸媒轉化器相連。 因此’在此實施例，一種用於内燃機丨〇之排氣循環系統， 具有連接於引擎之排氣系統的EGR(氣體）排出管32，該排氣 糸統包括位於觸媒轉化器22下的用於排出由引擎産生的排 氣並將其循環至引擎之進氣系統的排氣導管24，在將該排 氣糸統之排氣導管24彎曲的同時將其連接.至觸媒轉化器22 的下游端，且將該EGR排出管32於排氣導管24之彎曲所朝 向之側上連接至排氣導管3 5。另外，在相對於觸媒轉化器 且與ACG (輔助裝置）14等相反之側上，將該EGR排出管32 與排氣導管24連接。 O:\91\91472.DOC -10- 1237674 EGR排出管32之中間部分形成爲波紋狀部分32a。如圖所 示，該波紋狀部分32a具有波狀結構，其增大了與週圍空氣 的接觸面積。此有助於藉由驅散穿過EGR排出管32之排氣 (EGR氣體）中的熱量來冷卻該排氣（£〇11氣體）。 該EGR排出管32從觸媒轉化器22下游側延伸至法蘭 2〇a，藉由該法蘭2〇a將其另一端與主引擎單元1〇&相連接。 具體言之，如圖6所示，該EGR排出管藉由於其插入一形成 於该法蘭20a内之孔20al的一頂部32b處焊接而附著至法蘭 20a。接著’如圖3所示，使螺栓26穿過形成於法蘭2〇a内的 孔並擰入形成於主引擎單元側壁上的螺栓插入孔，以 完成連接。 该EGR排出管32及法蘭20a藉由一支架32c而橋接，藉 此，藉由支架32c來將EGR排出管32與法蘭20a藉由相互連 接（支架32c在圖3中被省略）。將該支架32(：在位於波紋狀部 分32a之下游一點處附著至該EGR排出管32。（在說明書中， 術語“下游”及“上游，，是相對於EGR氣體從排氣系統向 進氣系統的流動而定的。）支架32c藉由焊接與法蘭20a結 合，藉此使法蘭20a與支架32c成爲一體。 因此，在該實施例中，排氣系統包括藉由法蘭2〇c而固定 至主引擎單元10之排氣歧管2〇，且EGR排出管32藉由支架 32c而連接至法蘭20c，該該支架32c在該波紋狀部分32a之 下游的一點處附著至該EGR排出管32，且支架32c與法蘭 20c結合而成爲一體。 如圖6所示’頂部32b於附著至法蘭20a之部分減小了直 O:\9I\9I472.DOC -11- 1237674 徑。換言之，EGR排出管32至其與主引擎單元i〇a相連接部 分之直徑（内直徑dl)大於連接部分的直徑（内部直徑d2)。由 於此使得與週圍空氣相接觸的表面面積增大至連接部分， 因此其亦能藉由驅散該流經EGR排出管3 2之EGR氣體的熱 量以有助於冷卻該氣體。 如圖7所7F，連接至主引擎單元i0a2EGR排出管隨後藉 由一形成於主引擎單元l〇a之氣缸蓋内部的蓋内通道 而與EGR閥36相通。該EGR閥36調節EGR氣體的流速且藉由 一第二蓋内通道l〇a2與進氣側18相通。因此，egr氣體流 經蓋内通道l〇al、EGR閥36及第二蓋内通道1〇心，以循環 入或返回進氣系統。以該說明之方式形成於第二蓋内通道 10a2附近的引擎冷卻劑通道l〇a3可冷卻EGR氣體。 如圖1所示’在根據該實施例之排氣循環系統中，排氣歧 管20及觸媒轉化器22兩者皆位於車輛12的前部，並因此曝 露於在車輛運行時藉由前栅格12b進入的氣流（由車輛運行 産生）中。散熱器3 8雖安裝於前柵格12b之後，然而，流經 5亥政熱器3 8之氣流到達觸媒轉化器2 2而其他氣流在其他車 載元件（未圖示）之間彎曲進而吹至並冷卻觸媒轉化器22。 如上所述，配置該實施例使得在用於内燃機丨〇之排氣循 環系統中，其具有一連接至引擎之排氣系統的氣體排出管 (EGR排出管32)，該排氣系統包括一位於觸媒轉化器22下游 之位置、用於排出由引擎產生的排氣以使其循環至引擎之 進氣系統的排氣導管24，在將排氣系統之排氣導管，f曲的 同時將其連接至觸媒轉化器之下游端，且將氣體排出管在 O:\91\91472.DOC -12- 1237674 排氣‘官之彎曲所朝向的一側上連接至排氣導管。如此， 可縮短EGR排出管的長度並增大其剛性，同時由於不存在 任何突出部分，亦保存了排氣系統的空間。 在該系統中，在相對於觸媒轉化器22且與由引擎1〇驅動 的輔助裝置（ACG 14等）相反之一側上，將氣體排出管（E(}r 排出管32)連接至排氣導管24。因此，該配置不僅能達成前 述效果，亦可減輕由EGR排出管32散出的熱量對ACG14 (交 流發電機)、空氣調節器麼縮機16及其它此等由引擎10所驅 動，輔助裝置所造成的影響。此外，還可適當定位EGR排 出管32以避免安裝於辅助裝置之側及其它空間相當有限之 位置。 在4系、’先中，排氣系統包括一藉由法蘭而固定至引擎 0之主單元l〇a上的排氣歧管2〇，且藉由支架Wc將氣體排 出管（EGR棑出管32)連接至法蘭心。目此，此配置可藉由 支架32C來增大EGR排出管之剛性。此外，EGR排出管之熱 里可藉由熱傳遞而傳遞至法蘭2〇a或藉由支架釋放至空氣中。 、在該系統中，氣體排出管（EGR排出管32形成有波紋狀部 ^大了與週圍空氣接觸的面積，以便有助於冷卻流 «中的排氣，且支架32c在該波紋狀部分之下游的一點處 附著於氣體排出管。此配置藉由縮短支架32。而達成增大了 的EGR排出管之剛性。 在該系統中，支架32c與法蘭2〇a結合以成爲一體。此配， 置不僅可達成上述的效果及優點，亦可減少元件的數量及 裝配步驟。O: \ 9J \ 9 U72.DOC 1237674 The exhaust gas ′ g 24 is connected to the downstream end of the cylindrical casing of the catalytic converter 22. The exhaust duct 24 is formed with a tapered portion 24a whose diameter gradually decreases from directly below the catalyst converter 22. As best shown in FIG. 2, the exhaust duct 24 is configured in a curved shape to gradually move away from auxiliary devices such as agc μ and the air conditioner compressor 16. The exhaust duct 24 is connected to a more exhaust exhaust duct (not shown) through a flange 24b. The EGR exhaust pipe (gas exhaust pipe) 32 is connected to the tapered portion 24a of the exhaust duct to exhaust the exhaust gas and circulate it to the intake system as EGR gas. The intake system includes an intake duct and is located on the intake side. 1 of the 8 engines entered the chaos. Specifically, the EGR discharge pipe 32 is inserted into a hole formed in the tapered portion 24a, and is fixed at this position by welding. Therefore, while the exhaust guide 24 is bent, it is connected to the catalyst converter 22 (in a bent form) 'and the EGR exhaust pipe 32 is connected to the side where the exhaust duct 24 is bent. Further, the Egr discharge pipe 32 is connected to the catalyst converter on the side of the catalyst converter 22 opposite to the agc 14 and the like. Therefore, in this embodiment, an exhaust gas circulation system for an internal combustion engine has an EGR (gas) exhaust pipe 32 connected to the exhaust system of the engine. The exhaust system includes a The exhaust duct 24 for exhausting the exhaust gas generated by the engine and circulating it to the intake system of the engine, and connecting the exhaust duct 24 of the exhaust system while bending it. To the catalyst converter 22 The downstream end of the EGR exhaust pipe 32 is connected to the exhaust pipe 35 on the side to which the exhaust pipe 24 is bent. In addition, the EGR exhaust pipe 32 is connected to the exhaust duct 24 on the side opposite to the catalyst converter and opposite to the ACG (auxiliary device) 14 and the like. O: \ 91 \ 91472.DOC -10- 1237674 The middle portion of the EGR discharge pipe 32 is formed as a corrugated portion 32a. As shown in the figure, the corrugated portion 32a has a corrugated structure which increases the contact area with the surrounding air. This helps to cool the exhaust gas (the EGR gas) by dissipating the heat in the exhaust gas (the EGR gas) passing through the EGR exhaust pipe 32. The EGR exhaust pipe 32 extends from the downstream side of the catalyst converter 22 to the flange 20a, and the other end thereof is connected to the main engine unit 10 & through the flange 20a. Specifically, as shown in FIG. 6, the EGR exhaust pipe is attached to the flange 20a by being inserted into a top portion 32b of a hole 20al formed in the flange 20a by welding. Next, as shown in FIG. 3, the bolt 26 is passed through the hole formed in the flange 20a and screwed into the bolt insertion hole formed on the side wall of the main engine unit to complete the connection. The EGR exhaust pipe 32 and the flange 20a are bridged by a bracket 32c, whereby the EGR exhaust pipe 32 and the flange 20a are interconnected by the bracket 32c (the bracket 32c is omitted in Fig. 3). The bracket 32 (is attached to the EGR discharge pipe 32 at a point downstream of the corrugated portion 32a. (In the description, the terms "downstream" and "upstream" refer to the intake of air from the exhaust system relative to the EGR gas The flow of the system is determined.) The bracket 32c is combined with the flange 20a by welding, thereby integrating the flange 20a and the bracket 32c. Therefore, in this embodiment, the exhaust system includes the flange 20c. The exhaust manifold 20 fixed to the main engine unit 10, and the EGR exhaust pipe 32 is connected to the flange 20c by a bracket 32c, which is attached to the EGR at a point downstream of the corrugated portion 32a. The discharge pipe 32, and the bracket 32c and the flange 20c are combined into one body. As shown in FIG. 6, the portion of the top 32b attached to the flange 20a has a reduced diameter of O: \ 9I \ 9I472.DOC -11-12674674. In other words, the diameter (inner diameter d1) of the EGR exhaust pipe 32 to its connecting portion with the main engine unit i0a is larger than the diameter of the connecting portion (internal diameter d2). Due to this, the surface area in contact with the surrounding air is increased to Connection part, so it can also dissipate the flow through the EGR exhaust The heat of the EGR gas in the pipe 32 helps to cool the gas. As shown in FIG. 7F, the EGR exhaust pipe connected to the main engine unit i0a2 is then passed through a cover passage formed inside the cylinder head of the main engine unit 10a. It communicates with the EGR valve 36. The EGR valve 36 regulates the flow rate of the EGR gas and communicates with the intake side 18 through a second cover passage 10a2. Therefore, the egr gas flows through the cover passage 10al, the EGR valve 36 and the second cover inner channel 10 center to circulate into or return to the air intake system. The engine coolant channel 10a3 formed near the second cover inner channel 10a2 in this way can cool the EGR gas. See Figure 1 Shown 'In the exhaust gas circulation system according to this embodiment, both the exhaust manifold 20 and the catalyst converter 22 are located at the front of the vehicle 12 and are therefore exposed to the front grille 12b when the vehicle is running Incoming airflow (produced by vehicle operation). Although the radiator 38 is installed behind the front grid 12b, the airflow passing through the heater 5 8 reaches the catalyst converter 2 2 and the other airflow is in other vehicles. The elements (not shown) are bent to blow and cool the catalyst converter 22. As described above, this embodiment is configured such that in an exhaust gas circulation system for an internal combustion engine, it has a gas exhaust pipe (EGR exhaust pipe 32) connected to the exhaust system of the engine, and the exhaust system includes a A downstream of the catalytic converter 22 is an exhaust duct 24 for exhausting the exhaust gas generated by the engine to circulate to the engine's intake system. Connect to the downstream end of the catalytic converter, and connect the gas exhaust pipe to the exhaust pipe on the side facing the bend of the exhaust gas O: \ 91 \ 91472.DOC -12- 1237674. In this way, the length and rigidity of the EGR exhaust pipe can be shortened and the space of the exhaust system can be saved because there are no protruding parts. In this system, a gas exhaust pipe (E (} r exhaust pipe 32) is connected to the exhaust pipe on the side opposite to the catalyst converter 22 and on the side opposite to the auxiliary device (ACG 14 etc.) driven by the engine 10. Air duct 24. Therefore, this configuration can not only achieve the aforementioned effects, but also reduce the heat emitted by the EGR exhaust pipe 32 to the ACG14 (alternator), the air conditioner 16 and the other driven by the engine 10. , The impact caused by the auxiliary device. In addition, the EGR exhaust pipe 32 can be appropriately positioned to avoid being installed on the side of the auxiliary device and other places with relatively limited space. In the 4 series, the first, the exhaust system includes a method It is fixed to the exhaust manifold 20 on the main unit 10a of the engine 0, and the gas exhaust pipe (EGR evacuation pipe 32) is connected to the flange core through the bracket Wc. For this reason, this configuration can be borrowed The rigidity of the EGR exhaust pipe is increased by the bracket 32C. In addition, the heat of the EGR exhaust pipe can be transferred to the flange 20a by heat transfer or released into the air through the bracket. In this system, the gas is exhausted The pipe (EGR discharge pipe 32 is formed with a corrugated portion, which is large and connected to the surrounding air. To facilitate exhaust in the cooling flow «, and the bracket 32c is attached to the gas exhaust pipe at a point downstream of the corrugated portion. This configuration achieves increased EGR emissions by shortening the bracket 32. The rigidity of the tube. In this system, the bracket 32c is combined with the flange 20a to become one body. This configuration and arrangement can not only achieve the above-mentioned effects and advantages, but also reduce the number of components and assembly steps.
O:\91\9I472 DOC -13- 1237674 應注意，上述觸媒棘外哭、μ ^ 、得化的非侷限用於所說明的構造，而 可以任何所需之方式來配置。 還應注意’本發明亦可應用於外置馬達或其他用於驅動 船隻之引擎’其中引擎ίο之曲軸垂直定向。 【圖式簡單說明】 自上文的描述及圖式，本發明之上述與其他目的及優勢 將更爲顯而易見，在該等圖式中·· 圖1係一透視圖，展示根據本發明之一實施例的安裝於車 輛内的用於内燃機之排氣循環系統； 圖2係一透視圖，展示安裝於引擎上的圖1所示之排氣循 壞糸統； 圖3係一透視圖，展示圖1之排氣循環系統連同排氣歧管； 圖4係圖3中所示的排氣循環系統的部分剖視圖； 圖5係圖3中所示的排氣循環系統的側視圖。 圖6係圖4中所示的排氣循環系統之部分的放大剖視圖； 及 圖7係圖2中所示的氣缸蓋之示意剖視圖。 【圖式代表符號說明】 10 引擎 10a 主引擎單元 10al 蓋内通道 10a2 第二蓋内通道 10a3 冷卻劑通道 12 車輛 O:\91\91472.DOC -14- 1237674 12a 引擎艙 12b 前栅格 14 交流引擎 16 空氣調節器壓縮機 18 進氣側 20 排氣歧管 20a 法蘭 20al 子L 22 觸媒轉化器 22a 圓柱形殼體 22b 催化床層 22c 托架 24 排氣導管 24a 排氣導管之錐形部分 24b 法蘭 26 螺栓 30 插入塾圈 32 EGR排出管 32a 波紋狀部分 32b 頂部 32c 支架 36 EGR閥 38 散熱器 O:\9I\91472.DOC -15 -O: \ 91 \ 9I472 DOC -13- 1237674 It should be noted that the above mentioned catalysts are not limited to the described construction and can be configured in any desired manner. It should also be noted that the present invention can also be applied to external motors or other engines used to drive ships, where the crankshaft of the engine is oriented vertically. [Brief description of the drawings] From the above description and drawings, the above and other objects and advantages of the present invention will be more obvious. Among these drawings, Fig. 1 is a perspective view showing one of the views according to the present invention. An embodiment of an exhaust gas circulation system for an internal combustion engine installed in a vehicle; FIG. 2 is a perspective view showing the exhaust gas cycle system shown in FIG. 1 installed on the engine; FIG. 3 is a perspective view showing The exhaust circulation system of FIG. 1 together with the exhaust manifold; FIG. 4 is a partial cross-sectional view of the exhaust circulation system shown in FIG. 3; and FIG. 5 is a side view of the exhaust circulation system shown in FIG. 3. 6 is an enlarged sectional view of a part of the exhaust gas circulation system shown in FIG. 4; and FIG. 7 is a schematic sectional view of the cylinder head shown in FIG. [Illustration of representative symbols of the drawings] 10 engine 10a main engine unit 10al inside cover passage 10a2 second cover passage 10a3 coolant passage 12 vehicle O: \ 91 \ 91472.DOC -14- 1237674 12a engine compartment 12b front grid 14 AC Engine 16 Air conditioner compressor 18 Intake side 20 Exhaust manifold 20a Flange 20al Sub L 22 Catalyst converter 22a Cylindrical case 22b Catalytic bed 22c Bracket 24 Exhaust duct 24a Exhaust duct cone Section 24b Flange 26 Bolt 30 Inserted into the ring 32 EGR exhaust pipe 32a Corrugated section 32b Top 32c Bracket 36 EGR valve 38 Radiator O: \ 9I \ 91472.DOC -15-