200902837 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種引擎減壓裝置之配置，尤指一種適 用於四行程内燃機頂置凸輪引擎之減壓裝置配置。 、 【先前技術】 ( 10BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of an engine decompression device, and more particularly to a decompression device configuration suitable for a four-stroke internal combustion engine overhead cam engine. , [Prior Art] (10
一般四行程内燃機之曲柄軸於内燃機熄火而停止後’ 若恰停於壓縮行程，則下次内燃機重新啟動由於活塞進行 壓縮行程之故，活塞需承受燃燒室之氣體壓力亦即啟動^ 達必須提供的扭力較大，以克服啟動阻抗，這常造成啟動 馬達及電池的規格大型化。又，騎乘者於發動引擎時需施 以較大腳踏力量踩踏發動桿.，因而造成不便。為改進上= 缺點，已有各種可洩除、減少内燃機啟動壓力之減壓裝置 設計被提出，例如以離心原理而發揮減壓作用之設計。 參考圖1，習知頂置凸輪引擎之減壓裝置5係配置於汽 缸頭1的凸輪室2中，且其配置係使減a裝置5與閥動凸輪6 皆位於支樓凸輪軸7之兩軸承3、4之間。然而，此種減壓两裝 置配設方式使得凸輪軸7之支撐跨矩因減壓裝置5之額外附 加而不可避免地加大，進而使整個凸輪室2之空間需求變 大，造成汽缸頭1結構配置之設計困難度提升，而且也因附 加減壓裝置5而使原本凸輪系統中各元件之幾何配 新設計之必要。 【發明内容】 20 200902837 驅ΓΓ ㈣置之配置包括有-凸輪軸總成、 一=、以及一減《置。凸輪軸總成包括-凸輪轴、 軸承、一後端軸承'及至少一間動凸輪，其中公輪 軸分別承置於前端軸承與後 凸輪轴並職有-容置槽。 ，閥動凸輪套設於 上述驅動輪_套設於凸輪軸上，且㈣於後端轴承 之後。上述減塵裝置則包括一轉動殼體離心臂、一彈 性構件、及一洩壓桿。轉動殼體同軸套設於凸輪軸上，且 排列於後端軸承與驅動輪之間。 10 15 Ο 上述離心臂抱設於轉動殼體，且框轉於—第一位置至 :-第二位置間。彈性構件二端分別抵頂轉動殼體與離心 !二使離心臂常時位於第-位置。⑽捍-端徑向向外 而开導Γ ’導臂抵靠離心臂，㈣桿另—端則收容於 夺置槽而形成一容置端。 當離心臂位於第-位置時之容置端突出於容 ί槽：於壓縮行程之引擎之間門可被頂㈣ s 4又引擎啟動後之旋轉運動之離心力抵抗彈性 =位於第二位置時，茂壓桿被離心臂帶動轉動而使容 二置槽中。藉由上述結構配置使得凸輪室 °计二間侍以朝密集化邁進，且所需之設計變更少。 ;引擎減壓裝置之配置可更包含有一吹漏氣離心盤，其 、、且〇X於以上述驅動輪為分界相對於減壓裝 — 避免吹漏氣現象。 則错此 上述容置端可具有由較大之一截面長度以及較小之一 20 200902837 截:寬度所構成之截面，此處截面是指橫切面而言。且容 置^之冰度介於上述截面長度與截面寬度之間，以使當離 心臂位於第—位置時’容置端以較長之截面長度突出：容 置槽。例如半月狀截面容置端，其容置端形態為一平面及 5二’面所構成’平面之橫向長度（亦為兩圓弧端點之距離） 定義出上述截面長度，而平面至圓弧面頂端距離定義出上 述截面寬度。因此容置端是否凸出於容置槽面，是由 桿旋轉而定。 減壓裝置之轉動殼體可以壓配方式固定於上述凸輪 10軸；減壓裝置之離心臂可為弧形以配合轉動殼體外型。上 述前端軸承、後端軸承可為滾動軸承或平面軸承。上述驅 動輪可為一鍊輪或皮帶輪。上述彈性構件可為—扭簧。 【實施方式】 15 參考圖2 ’其緣示本發明一較佳實施例之引擎減壓裝置 配置之側剖面圖。本實施例之引擎減壓裝置之配置包括有 一凸輪軸總成10、一驅動輪11、一減壓裝置12、以及一吹 漏氣離心盤13，上述凸輪軸總成1〇之各元件組裝於凸輪室 20中。 Ό 凸輪軸總成10包括有一凸輪軸101、一前端軸承1〇2、 一後端軸承103、及一閥動凸輪104,凸輪軸ι〇1分別承置於 前端軸承102與後端轴承103上，閥動凸輪104套設於凸輪軸 1(U，且開設有一容置槽105(繪於圖4)。容置槽1〇5係同時開 口於閥動凸輪104之環向表面1〇41與軸向表面1〇42(繪於圖 200902837 4) 〇 同時參考圖3與圖4，驅動輪1丨為一鍊輪，其同軸套設 於凸輪軸1 〇 1上且位於後端軸承1 〇3之後，亦即位於凸輪軸 101上、上述轴承102、103之同一側，其中後端軸承1 〇3係 5 指較前端軸承1 〇2更靠近驅動輪11者。軸承1 〇2、1 〇3皆使用 滾動轴承。 減壓裝置12包括一轉動殼體121、一離心臂122、一彈 性構件123、及一洩壓桿124。轉動殼體丨21包括一中空基部 1211、及自中空基部1211軸向突伸出之一中空筒部pi〗。 10 轉動殼體121係同軸壓配固定於凸輪軸101 ,且位於後端軸 承103與驅動輪11之間。中空基部丨2丨i之表面更形成有一第 —套設部1213、一限位部1214、及一第一抵頂部丨215。 離心臂122呈弧形，且包括有一缺口丨27、一第二抵頂 部1221、及一第二套設部1222。離心臂122透過第二套設部 15 1222樞設於轉動殼體12卜且枢轉於一第一位置至與一第二 位置間，其中離心臂122之第一位置狀態如圖5(a)所示，其 ) 第二位置狀態如圖5(b)所示。限位部1214與第一抵頂部i2i5 之設置分別決定了離心臂122之第一位置與第二位置。 本實施例中彈性構件123為一扭簧，其套設於第一套設 20部1213與第二套設部1222，扭簧即以第一套設部如與第 二套設部1222為扭轉支點。彈性構件123之第—端η”及第 二端1232分別抵頂於轉動殼體121之第一抵頂部Kb及離 心臂122之第二抵頂部122卜藉由扭簧之預扭矩以使離心臂 122常時位於第一位置。此處常時狀態係指離心臂m單純 200902837 受彈性構件預負載作用，而尚未有旋轉離心力之因素之狀 態。 洩壓桿124 —端之表面徑向向外突設有一導臂丨25。導 臂125於缺口 127内抵靠著離心臂122。洩壓桿124另一端收 5谷於谷置槽105，稱其為容置端126,且容置端126為半月狀 截面’因此該截面形態為具有一平面1261及一圓弧面 1262(繪於圖6)所構成，其中圓弧面1262之兩圓弧端點定義 出截面長度L，平面1261與圓弧面1262之最大距離則定義 出一截面寬度W，且容置槽105之深度D介於截面寬度…與 10截面長度L之間，如圖8所示。因此容置端126是否凸出於容 置槽105面，是由洩壓桿124旋轉而定，其可以載面長度匕而 突出於容置槽1〇5頂、亦可以截面寬度w而收納於容置槽 1〇5内。吹漏氣離心盤13係組設於驅動輪丨丨之後，亦即以^ 動輪11為分界相對於減塵裝置12之—側。 15 配合圖3參考圖5與圖6,其分別繪示引擎減壓裝置之離 心臂於第一位置及第二位置時之立體示意圖、剖切圖。以 下將說明減壓裝置之作動過程。 ； 首先考慮圖5(a)與圖6(a)，當引擎停止運轉於壓縮行程 時，由於凸輪軸1 〇 1停止轉動，離心臂i 22受彈性構件1之 20預力被固定於位於第一位置，且同時離心臂122將洩壓桿 124之導臂125推擠固定於定位，在此定位時洩壓桿丨24之容 置端126的截面以圓弧面1262凸出於容置槽1〇5。由於洩壓 杯124容置端126以圓弧面1262較閥動凸輪1〇4更突出，其突 出部分將可頂開搖臂（圖未示），進而使閥門（圖未示）產生額 200902837 外揚程，達到洩除燃燒室（圖未示）内原先較高之壓力。 接著考慮圖5(b)與圖6(b)，當引擎自壓縮行程開始轉 動，離心臂122也開始受到對應於該引擎轉速之離心力量。 達疋轉速時，離心臂122所受離心力足以抵抗彈性構件 123而被甩至第二位置，同時洩壓桿124也透過導臂丨25被離 心臂122拉動而近乎以自身轴線轉動一角度，此時洩壓桿 124之容置端126，由圓弧面1262旋轉至平面126丨，且容置 端126之平面1261不再突出，而是完全收納於容置槽1〇5 中。此後凸輪系統因洩壓桿124低於閥動凸輪1〇4之基圓， 故不再影響閥門之正常運作。 為更清楚瞭㈣心臂由第一位置至第二位置之狀態變 化，可另外參考圖7(a)、（b)。圖7(a)表示離心臂於第一位置 時之狀態，圖7(b)表示離心臂於第二位置時之狀態。 15Generally, the crankshaft of the four-stroke internal combustion engine is stopped after the internal combustion engine is turned off. If the piston is stopped for the next time, the piston is subjected to the compression stroke of the piston, and the piston must withstand the gas pressure of the combustion chamber, that is, the start-up must be provided. The torque is large to overcome the starting impedance, which often causes the size of the starting motor and the battery to be large. Moreover, the rider needs to apply a large pedaling force to step on the launching lever when starting the engine, thereby causing inconvenience. In order to improve the above-mentioned disadvantages, various decompression device designs capable of venting and reducing the starting pressure of the internal combustion engine have been proposed, for example, a design that exerts a decompression action by the centrifugal principle. Referring to Figure 1, the pressure reducing device 5 of the conventional overhead cam engine is disposed in the cam chamber 2 of the cylinder head 1 and is disposed such that both the a reducing device 5 and the valve moving cam 6 are located in the double shaft of the branch camshaft 7. Between the bearings 3, 4. However, such a decompression device is arranged such that the supporting span of the camshaft 7 is inevitably increased by the additional addition of the decompression device 5, thereby increasing the space requirement of the entire cam chamber 2, resulting in the cylinder head 1 The design of the structural arrangement is difficult to improve, and the additional design of the components of the original cam system is necessary for the additional decompression device 5. [Summary] 20 200902837 ΓΓ (4) The configuration includes a camshaft assembly, a =, and a minus. The camshaft assembly includes a camshaft, a bearing, a rear bearing, and at least one movable cam, wherein the male axle is respectively received by the front end bearing and the rear camshaft and has a receiving groove. The valve cam is sleeved on the driving wheel _ sleeve on the cam shaft and (d) after the rear end bearing. The dust removing device includes a rotating housing centrifugal arm, an elastic member, and a pressure relief lever. The rotating housing is coaxially sleeved on the camshaft and arranged between the rear bearing and the drive wheel. 10 15 Ο The above-mentioned centrifugal arm is hung on the rotating housing, and the frame is rotated between the first position and the :- second position. The two ends of the elastic member respectively abut the rotating housing and centrifuge! Second, the centrifugal arm is always in the first position. (10) The 捍-end is radially outward and the Γ ’ guide arm abuts the centrifugal arm, and the other end of the (4) rod is received in the accommodating groove to form a receiving end. When the centrifugal arm is in the first position, the receiving end protrudes from the receiving groove: between the engine of the compression stroke, the door can be topped (four) s 4 and the centrifugal force of the rotating motion after the engine is started to resist elasticity = when in the second position, The pressing rod is rotated by the centrifugal arm to make the second slot. With the above-described structural configuration, the two chambers of the cam chamber are moving towards intensiveness, and the required design changes are small. The configuration of the engine pressure reducing device may further include a blow-by gas centrifugal disk, and the 〇X is spaced apart from the pressure-reducing device by the above-mentioned driving wheel to avoid blowing air leakage. Then, the above-mentioned receiving end may have a section formed by a larger one-section length and a smaller one, and the cross-section is a cross-section. And the ice content of the accommodation is between the length of the section and the width of the section so that when the centering arm is at the first position, the receiving end protrudes with a longer section length: the receiving groove. For example, the half-moon section of the receiving end, the receiving end is shaped as a plane and the lateral length of the 'plane' formed by the 5'' plane (also the distance between the ends of the two arcs) defines the length of the section, and the plane to the arc The top end distance defines the above cross-sectional width. Therefore, whether or not the receiving end protrudes from the receiving groove surface is determined by the rotation of the rod. The rotating housing of the pressure reducing device may be press-fitted to the cam shaft 10; the centrifugal arm of the pressure reducing device may be curved to match the shape of the rotating housing. The front end bearing and the rear end bearing may be a rolling bearing or a planar bearing. The drive wheel can be a sprocket or a pulley. The elastic member may be a torsion spring. [Embodiment] FIG. 2 is a side cross-sectional view showing the arrangement of an engine decompression device according to a preferred embodiment of the present invention. The configuration of the engine pressure reducing device of this embodiment includes a camshaft assembly 10, a driving wheel 11, a pressure reducing device 12, and a blow-by gas centrifugal disk 13, and the components of the camshaft assembly 1 are assembled. In the cam chamber 20.凸轮 The camshaft assembly 10 includes a camshaft 101, a front end bearing 1〇2, a rear end bearing 103, and a valve moving cam 104. The camshaft ι〇1 is respectively received on the front end bearing 102 and the rear end bearing 103. The valve cam 104 is sleeved on the cam shaft 1 (U, and has a receiving groove 105 (shown in FIG. 4). The receiving groove 1〇5 is simultaneously opened on the circumferential surface of the valve cam 104. Axial surface 1〇42 (pictured in Fig. 200902837 4) 〇 Referring to FIG. 3 and FIG. 4 simultaneously, the driving wheel 1 is a sprocket coaxially sleeved on the camshaft 1 〇1 and located at the rear end bearing 1 〇 3 Thereafter, that is, on the same side of the above-mentioned bearings 102, 103 on the camshaft 101, wherein the rear end bearing 1 〇 3 is a finger closer to the drive wheel 11 than the front end bearing 1 〇 2. Bearing 1 〇 2, 1 〇 3 The rolling device 12 includes a rotating housing 121, a centrifugal arm 122, an elastic member 123, and a pressure relief rod 124. The rotating housing 21 includes a hollow base 1211 and a hollow base 1211 shaft. One of the hollow tubular portions pi is protruded. 10 The rotating housing 121 is coaxially press-fitted to the camshaft 101 and located at the rear end bearing 103. The driving wheel 11 is formed with a first sleeve portion 1213, a limiting portion 1214, and a first abutting top portion 215. The centrifugal arm 122 is curved and includes a notch.丨27, a second abutting top 1221, and a second arranging portion 1222. The centrifugal arm 122 is pivoted to the rotating housing 12 through the second sleeve portion 151222 and pivoted to a first position to a first In the two positions, the first position state of the centrifugal arm 122 is as shown in Fig. 5(a), and the second position state is as shown in Fig. 5(b). The setting of the limiting portion 1214 and the first abutting top i2i5 respectively determines the first position and the second position of the centrifugal arm 122. In this embodiment, the elastic member 123 is a torsion spring, and is sleeved on the first sleeve 20 portion 1213 and the second sleeve portion 1222. The torsion spring is twisted by the first sleeve portion and the second sleeve portion 1222. Pivot. The first end η" and the second end 1232 of the elastic member 123 respectively abut against the first abutting top Kb of the rotating housing 121 and the second abutting top 122 of the centrifugal arm 122 by the pre-torque of the torsion spring to make the centrifugal arm 122 is always in the first position. Here, the constant state refers to the state in which the centrifugal arm m is simply 200902837, which is preloaded by the elastic member, and has no factor of rotating centrifugal force. The surface of the pressure releasing rod 124 is radially outwardly protruded The guide arm 125. The guide arm 125 abuts against the centrifugal arm 122 in the notch 127. The other end of the pressure relief rod 124 receives the valley 5 in the valley groove 105, which is referred to as the receiving end 126, and the receiving end 126 is half-moon shaped. The cross section 'so the cross-sectional shape is composed of a plane 1261 and a circular arc surface 1262 (drawn in FIG. 6 ), wherein the two arc ends of the circular arc surface 1262 define the section length L, the plane 1261 and the circular plane 1262 The maximum distance defines a section width W, and the depth D of the accommodating groove 105 is between the section width... and the section length L, as shown in FIG. 8. Therefore, whether the accommodating end 126 protrudes from the accommodating groove The 105 face is determined by the rotation of the pressure relief lever 124, which can protrude from the length of the carrier surface. The accommodating groove 1 〇 5 top or the cross-sectional width w may be accommodated in the accommodating groove 1 〇 5. The blow-by gas centrifugal disk 13 is assembled after the driving rim, that is, the boundary of the driving wheel 11 is opposite to The side of the dust-reducing device 12 is similar to that of Figure 3 with reference to Figure 5 and Figure 6, which respectively show a perspective view and a cut-away view of the centrifugal arm of the engine pressure reducing device in the first position and the second position. The operation of the pressure reducing device. First, considering FIG. 5(a) and FIG. 6(a), when the engine stops running at the compression stroke, the centrifugal arm i 22 is subjected to the elastic member 1 when the cam shaft 1 〇1 stops rotating. The pre-force is fixed in the first position, and at the same time, the centrifugal arm 122 pushes and fixes the guide arm 125 of the pressure-relief rod 124 to the positioning. When positioning, the cross-section of the receiving end 126 of the pressure-relief rod 24 is in a circular arc surface. 1262 protrudes from the receiving groove 1〇 5. Since the receiving end 126 of the pressure relief cup 124 protrudes more than the valve cam 1〇4 by the circular arc surface 1262, the protruding portion thereof can open the rocker arm (not shown). In turn, the valve (not shown) generates an external lift of 200,902,837 to reach the previously high pressure in the combustion chamber (not shown). Next, considering FIG. 5(b) and FIG. 6(b), when the engine starts to rotate from the compression stroke, the centrifugal arm 122 also begins to receive centrifugal force corresponding to the engine speed. When the rotation speed is reached, the centrifugal force of the centrifugal arm 122 is sufficient to resist The elastic member 123 is clamped to the second position, and the pressure releasing rod 124 is also pulled by the centrifugal arm 122 through the arm 22 to rotate about an angle with its own axis. At this time, the receiving end 126 of the pressure releasing rod 124 is The circular arc surface 1262 is rotated to the plane 126 丨, and the plane 1261 of the accommodating end 126 is no longer protruded, but is completely received in the accommodating groove 1 〇 5 . Thereafter, the cam system is no longer affected by the normal operation of the valve because the pressure relief rod 124 is lower than the base circle of the valve cam 1〇4. To further clarify (4) the state of the arm from the first position to the second position, reference may be made to Figs. 7(a) and (b). Fig. 7(a) shows the state of the centrifugal arm in the first position, and Fig. 7(b) shows the state of the centrifugal arm in the second position. 15
20 _本發明將減壓裝置之轉動殼體配置於後方軸承與驅重 輪之間，不再位於閥動凸輪與凸輪軸軸承之間，而是直名 利用原本未使用之空間，避免對現有汽缸頭設計進=大柄 度變更，如此也使得凸輪室可成為較小尺寸、而車辆亦^ 兼具有減壓功能及吹漏氣防止功能。 上述實施例僅係為了方便說明而舉例而已，本發明押 主張之權利範圍自應以申請專利範圍所述為準，2戸 於上述實施例。 并偟丨民 【圖式簡單說明】 圖1係習知引擎減壓裝置配置之側剖面圖。 10 200902837 圖2係本發明—較佳實施例之引擎減壓裝置配置 圖。 圖3係本發明—較佳實施例之引擎減壓敦置配置立體圖。 圖4係圖3引擎減壓裝置配置之分解圖。 圖5(a)、(b)係弓丨擎減壓裝置之離心臂於第一位置、第二位 置時之立體示意圖。 圖6(a)、（b)係圖5之剖切示意圖。 圖7(a)、（b)係圖5之縱剖面示意圖。 圖8係容置端與容置槽尺寸關係示意圖。 【主要元件符號說明】 汽紅頭1 凸輪室2 軸承3、4 減壓裝置5 閥動凸輪6 凸輪車由7 凸輪轴總成10 凸輪軸101 前端轴承102 後端軸承1〇3 閥動凸輪104 環向表面1041 軸向表面1042 谷置槽1 〇 5 驅動輪11 減壓裝置12 轉動殼體121 中空基部12 11 中空筒部1212 第一套設部1213 限位部1214 第一抵頂部1215 離心臂122 第二抵頂部1221 第二套設部1222 彈性構件123 20090283720 _ The present invention disposes the rotating housing of the pressure reducing device between the rear bearing and the driving wheel, and is no longer located between the valve moving cam and the camshaft bearing, but uses the originally unused space to avoid the existing The design of the cylinder head is changed to a large degree of handle, which also makes the cam chamber smaller, and the vehicle also has a decompression function and a blow-by gas prevention function. The above-described embodiments are merely examples for the convenience of the description, and the scope of the claims of the present invention is determined by the scope of the claims.偟丨民偟丨 [Simplified illustration of the drawings] Figure 1 is a side cross-sectional view of a conventional engine decompression device configuration. 10 200902837 Figure 2 is a configuration diagram of an engine decompression device of the present invention - a preferred embodiment. Figure 3 is a perspective view of the engine decompression configuration of the present invention - the preferred embodiment. Figure 4 is an exploded view of the configuration of the engine decompression device of Figure 3. Fig. 5 (a) and (b) are schematic perspective views of the centrifugal arm of the Bowen engine decompression device in the first position and the second position. 6(a) and (b) are schematic cross-sectional views of Fig. 5. 7(a) and 7(b) are schematic longitudinal sectional views of Fig. 5. Figure 8 is a schematic diagram showing the relationship between the size of the receiving end and the receiving groove. [Main component symbol description] Steam red head 1 Cam chamber 2 Bearing 3, 4 Pressure reducing device 5 Valve moving cam 6 Cam vehicle by 7 Camshaft assembly 10 Camshaft 101 Front end bearing 102 Rear end bearing 1〇3 Valve moving cam 104 Ring To the surface 1041 axial surface 1042 valley groove 1 〇 5 drive wheel 11 pressure reducing device 12 rotating housing 121 hollow base 12 11 hollow cylinder 1212 first set portion 1213 limiting portion 1214 first abutting top 1215 centrifugal arm 122 Second abutting top 1221 second sleeve 1222 elastic member 123 200902837
第一端1231 洩壓桿124 容置端126 圓弧面1262 吹漏氣離心盤13 截面長度L 容置槽之深度DThe first end 1231 the pressure relief rod 124 the receiving end 126 the circular surface 1262 the blown air centrifugal disk 13 the length of the section L the depth D of the receiving groove
第二端1232 導臂125 平面1261 缺口 127 凸輪室20 截面寬度WSecond end 1232 guide arm 125 plane 1261 notch 127 cam chamber 20 section width W
1212