TWI384119B - Engine variable drive valve assembly - Google Patents

Engine variable drive valve assembly Download PDF

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Publication number
TWI384119B
TWI384119B TW098126742A TW98126742A TWI384119B TW I384119 B TWI384119 B TW I384119B TW 098126742 A TW098126742 A TW 098126742A TW 98126742 A TW98126742 A TW 98126742A TW I384119 B TWI384119 B TW I384119B
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Taiwan
Prior art keywords
cam
exhaust
valve
shaft
intake
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TW098126742A
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Chinese (zh)
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TW201013034A (en
Inventor
Teruhide Yamanishi
Kazuo Fujihara
Kazuhiko Chiba
Yamato Nakamizo
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Honda Motor Co Ltd
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Publication of TW201013034A publication Critical patent/TW201013034A/en
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Publication of TWI384119B publication Critical patent/TWI384119B/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • F01L2001/0476—Camshaft bearings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Exhaust-Gas Circulating Devices (AREA)

Description

引擎的可變驅動汽門裝置Engine variable drive valve device

本發明是關於：在可自由旋轉地被汽缸頭所支承的凸輪軸上，固設著汽門驅動凸輪，並安裝有凸輪輪廓不同於該汽門驅動凸輪的異體凸輪，而可切換「使連動、連結於引擎汽門的汽門驅動構件，從動於前述汽門驅動凸輪」的狀態、及「使前述汽門驅動構件從動於與前述凸輪軸一起旋轉的前述異體凸輪」的狀態之引擎的可變驅動汽門裝置。According to the present invention, a valve driving cam is fixed to a cam shaft rotatably supported by a cylinder head, and a camshaft having a cam profile different from the valve driving cam is mounted, and the interlocking can be switched. a valve driving member coupled to the engine valve, a state of the slave valve driving cam, and an engine of a state in which the valve driving member is driven by the camshaft that rotates together with the camshaft Variable drive valve unit.

專利文獻1揭示一種引擎的可變驅動汽門裝置，該引擎的可變驅動汽門裝置是在一體設有汽門驅動凸輪之凸輪軸上鄰接於前述汽門驅動凸輪的位置，將凸輪輪廓不同於汽門驅動凸輪的異體凸輪安裝成不能相對旋轉，而可切換「使異體凸輪與凸輪軸及汽門驅動凸輪一體旋轉作動」的狀態、及「使異體凸輪相對於凸輪軸及汽門驅動凸輪而自由旋轉」的狀態，而這樣的技術已為大眾所知悉。Patent Document 1 discloses a variable drive valve device of an engine whose variable drive valve device is adjacent to the position of the aforementioned valve drive cam on a cam shaft integrally provided with a valve drive cam, and has a different cam profile The dissimilar cam of the valve driving cam is mounted so as not to be relatively rotatable, and the state of "rotating the camshaft and the camshaft and the cam driving cam integrally" can be switched, and "changing the camber with respect to the camshaft and the cam driving cam" The state of free spin, and such technology has been known to the public.

〔專利文獻1〕日本特開2007-146740號公報[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-146740

然而，在上述專利文獻1所揭示的可變驅動汽門裝置中，是藉由將不能與凸輪軸相對旋轉的鎖銷，嵌合在設於 異體凸輪的鎖銷嵌合部，而促使異體凸輪與凸輪軸及汽門驅動凸輪一體旋轉，而在鎖銷嵌合於前述鎖銷嵌合部時產生敲擊聲。However, in the variable drive valve device disclosed in Patent Document 1, the lock pin that cannot rotate relative to the cam shaft is fitted to The lock pin fitting portion of the foreign body cam causes the body cam to rotate integrally with the cam shaft and the valve drive cam, and a knocking sound is generated when the lock pin is fitted to the lock pin fitting portion.

本發明是有鑑於上述的問題所研發而成的發明，本發明的目的是提供一種：既能避免凸輪軸的大型化，又能抑制敲擊聲產生之引擎的可變驅動汽門裝置。The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable drive valve device that can prevent an increase in a camshaft and suppress an engine of knocking sound generation.

為了達成上述目的，請求項1所記載的發明，是下述之引擎的可變驅動汽門裝置：在透過第1軸承與第2軸承而可自由旋轉地被引擎本體的汽缸頭所支承的前述凸輪軸之第1與第2軸承間，用來驅動進氣汽門開閉的進氣凸輪、及用來驅動排氣汽門開閉的排氣凸輪，是將進氣凸輪配置於第1軸承側而設成一體，「凸輪輪廓不同於排氣凸輪，且用來驅動排氣汽門，而使從燃燒室所排出之排放氣體的一部分，回到前述燃燒室」的排放氣體再循環用凸輪，是在排氣凸輪與第2軸承之間安裝於凸輪軸，並且可切換「使連動、連結於排氣汽門的汽門驅動構件從動於排氣凸輪」的狀態、及「使汽門驅動構件，從動於可與凸輪軸一起旋轉的排放氣體再循環用凸輪」的狀態，其特徵為：在前述凸輪軸設有「與該凸輪軸同軸地延伸」中心孔、及「連結於該中心孔的內周面與前述凸輪軸的外周面間，且在前述凸輪軸的軸方向上長距離地延伸」的導引孔；「可在軸方向上移動且同軸地***前述中心孔內」的桿、及「可 移動於軸方向上且安裝於前述凸輪軸外周的」前述排放氣體再循環用凸輪，是由貫穿前述導引孔的連結銷所連結；可在「為了使前述汽門驅動構件從動於前述排氣凸輪，使前述排放氣體再循環用凸輪從前述排氣凸輪隔離」的非作動位置、與「為了使前述汽門驅動構件從動於前述排放氣體再循環用凸輪，使前述排放氣體再循環用凸輪接近前述排氣凸輪」的作動位置之間，於軸方向上驅動前述桿的桿驅動手段是連結於前述桿；該桿驅動手段具備「具有與前述凸輪軸平行的輸出軸，且被安裝於前述引擎本體」的電磁閥、及「透過支軸而可自由轉動地由前述引擎本體所支承」的轉動撥桿，並且在從前述支軸分離的2個位置，前述輸出軸及前述桿分別抵接於該轉動撥桿，使前述桿透過轉動撥桿而連動、連結於該輸出軸。In order to achieve the above object, the invention according to claim 1 is the variable drive valve device of the engine that is rotatably supported by the cylinder head of the engine body through the first bearing and the second bearing. An intake cam for driving the intake and exhaust valves to open and close, and an exhaust cam for driving the exhaust valve to open and close between the first and second bearings of the camshaft, wherein the intake cam is disposed on the first bearing side Integrally, "the cam profile is different from the exhaust cam, and the exhaust gas is used to drive the exhaust valve, and a part of the exhaust gas discharged from the combustion chamber is returned to the combustion chamber" A camshaft is attached between the exhaust cam and the second bearing, and a state in which "the interlocking of the valve driving member connected to the exhaust valve is driven by the exhaust cam" and "a valve driving member" can be switched. a state of the exhaust gas recirculation cam that is rotatable together with the camshaft, wherein the camshaft is provided with a center hole extending coaxially with the camshaft, and "connected to the center hole Inner circumferential surface and the aforementioned convex a guide hole extending between the outer peripheral surfaces of the axle and extending in the axial direction of the cam shaft; a rod that is movable in the axial direction and coaxially inserted into the center hole, and The exhaust gas recirculation cam that is moved in the axial direction and is attached to the outer periphery of the cam shaft is connected by a connecting pin that penetrates the guide hole; "in order to move the aforementioned valve drive member from the aforementioned row The air cam is configured to recirculate the exhaust gas by causing the exhaust gas recirculation cam to be separated from the exhaust cam by a non-actuated position and "to cause the valve drive member to be driven by the exhaust gas recirculation cam" A lever driving means for driving the lever in the axial direction is coupled to the lever between the actuating position of the cam close to the exhaust cam"; and the lever driving means includes "an output shaft parallel to the cam shaft and is attached to a solenoid valve of the engine body and a rotary lever that is rotatably supported by the engine body through a support shaft, and the output shaft and the lever are respectively abutted at two positions separated from the support shaft Connected to the rotating lever, the rod is linked and coupled to the output shaft through the rotating lever.

而實施形態的排氣側搖臂39是對應於本發明的汽門驅動構件，實施形態的第1滾珠軸承44是對應於本發明的第1軸承，實施形態的第2滾珠軸承45則對應於本發明的第2軸承。The exhaust side rocker arm 39 of the embodiment corresponds to the valve drive member of the present invention, and the first ball bearing 44 of the embodiment corresponds to the first bearing of the present invention, and the second ball bearing 45 of the embodiment corresponds to The second bearing of the present invention.

根據本發明，「可在軸方向上移動並安裝於凸輪軸外周」之作為異體凸輪的排放氣體再循環用凸輪、和***「同軸地設於凸輪軸的中心孔」的桿，是藉由貫穿「連結於中心孔之內周面與凸輪軸之外周面間，且在前述凸輪軸的軸方向上長距離延伸的導引孔」的連結銷所連結，而能以 「利用驅動手段在軸方向上對桿進行驅動」的簡易構造，來切換「使汽門驅動構件從動於排氣凸輪」的狀態、以及「使汽門驅動構件從動於排放氣體再循環用凸輪」的狀態，使排放氣體再循環用凸輪平時與凸輪軸一起旋轉，故能抑制切換作動時敲擊聲的產生，此外，藉由將桿收容於凸輪軸內，可避免凸輪軸的大型化。According to the present invention, the exhaust gas recirculation cam as the foreign body cam that can be moved in the axial direction and attached to the outer circumference of the camshaft, and the rod that is inserted into the "central hole that is coaxially disposed on the cam shaft" are passed through a connecting pin that is connected between the inner circumferential surface of the center hole and the outer circumferential surface of the cam shaft and has a long distance extending in the axial direction of the cam shaft is coupled to In the simple structure of "driving the rod in the axial direction by the driving means", the state in which "the valve driving member is driven by the exhaust cam" is switched, and "the valve driving member is driven to discharge the exhaust gas" In the state of the cam, the exhaust gas recirculation cam rotates together with the camshaft, so that the occurrence of the knocking sound during the switching operation can be suppressed, and the camshaft can be prevented from being enlarged by the rod being housed in the camshaft. .

此外，在「透過第1及第2軸承而可自由旋轉地被汽缸頭所支承之凸輪軸」的第1及第2軸承之間，「用來驅動進氣汽門開閉」的進氣凸輪、與「用來驅動排氣汽門開閉」的排氣凸輪，是將進氣凸輪配置於第1軸承側而設成一體，並將排放氣體再循環用凸輪，配置在排氣凸輪及第2軸承之間，故可在對凸輪軸形成良好的軸支承的狀態下，配置排放氣體再循環用凸輪。In addition, the "intake cam for driving the intake valve opening and closing" between the first and second bearings of the "camshaft that is rotatably supported by the cylinder head through the first and second bearings" The exhaust cam that is used to drive the exhaust valve opening and closing is provided integrally with the intake cam on the first bearing side, and the exhaust gas recirculation cam is disposed in the exhaust cam and the second bearing. Therefore, the exhaust gas recirculation cam can be disposed in a state in which the cam shaft is well supported by the shaft.

以下，參考圖面說明本發明的實施形態。Hereinafter, embodiments of the present invention will be described with reference to the drawings.

第1圖~第8圖是顯示本發明之實施形態的圖面，第1圖為引擎之重要部分的縱剖面圖，第2圖為第1圖中2-2線的剖面圖，第3圖為第2圖中箭號3所標示之部份的放大圖，第4圖是減壓停止狀態下之第3圖中4-4線的剖面圖，第5圖是顯示進氣汽門與排氣汽門之開啟汽門揚程特性的圖，第6圖是顯示減壓停止狀態下之第3圖中6-6線的放大剖面圖，第7圖為減壓裝置的分解立體圖，第8圖是對應於減壓啟動狀態下之第6圖的剖面圖。1 to 8 are views showing an embodiment of the present invention, wherein Fig. 1 is a longitudinal sectional view of an important part of the engine, and Fig. 2 is a sectional view taken along line 2-2 of Fig. 1, Fig. 3 An enlarged view of the portion indicated by the arrow 3 in Fig. 2, Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3 in the state of decompression stop, and Fig. 5 is a view showing the intake valve and the row Fig. 6 is an enlarged cross-sectional view showing the 6-6 line in Fig. 3 in the state in which the decompression is stopped, and Fig. 7 is an exploded perspective view of the decompression device, Fig. 8 It is a cross-sectional view corresponding to Fig. 6 in a state in which the decompression is activated.

首先，在第1圖及第2圖中，該引擎的引擎本體11，是譬如搭載於機車的引擎本體，前述引擎本體11具備：汽缸體12，該汽缸體12具有可供活塞15自由滑動地嵌合的汽缸孔16；和汽缸頭13，該汽缸頭13在其與前述汽缸體12之間形成有面向前述活塞15之頂部的燃燒室17，且結合於汽缸體12；和頭蓋14，該頭蓋14是從前述汽缸體12的相反側結合於該汽缸頭13；及曲軸箱(圖面中未顯示)，該曲軸箱是從前述汽缸頭13的相反側結合於前述汽缸體12。First, in the first and second figures, the engine body 11 of the engine is, for example, an engine body mounted on a locomotive, and the engine body 11 includes a cylinder block 12 having a piston 15 slidably provided. a fitting cylinder bore 16; and a cylinder head 13 formed between the cylinder block 12 and a combustion chamber 17 facing the top of the piston 15 and coupled to the cylinder block 12; and a head cover 14, The head cover 14 is coupled to the cylinder head 13 from the opposite side of the cylinder block 12, and a crankcase (not shown) that is coupled to the cylinder block 12 from the opposite side of the cylinder head 13.

在前述汽缸頭13設有：在其一側面形成開口的進氣埠18、及在汽缸頭13的另一側面形成開口的排氣埠19，形成有通往前述進氣埠18之進氣通路20的進氣管21是連接於前述汽缸頭13，並在該進氣管21附設有燃料噴射閥22。The cylinder head 13 is provided with an intake port 18 having an opening formed on one side thereof, and an exhaust port 19 forming an opening on the other side of the cylinder head 13, and an intake passage leading to the intake port 18 is formed. The intake pipe 21 of 20 is connected to the aforementioned cylinder head 13, and a fuel injection valve 22 is attached to the intake pipe 21.

此外，用來切換前述進氣埠18與前述燃燒室17間之連通、遮斷的進氣汽門24；及用來切換前述排氣埠19與前述燃燒室17間之連通、遮斷的排氣汽門25，是可開閉作動地配設於前述汽缸頭13，進氣汽門24及排氣汽門25是由汽門彈簧26、27朝汽門關閉方向彈推。不僅如此，在前述汽缸頭13還安裝有前端面向前述燃燒室17的火星塞23。Further, an intake valve 24 for switching the communication between the intake port 18 and the combustion chamber 17 and an interruption, and a row for disconnecting and blocking the communication between the exhaust port 19 and the combustion chamber 17 The gas valve 25 is disposed in the cylinder head 13 in an openable and closable manner, and the intake valve 24 and the exhaust valve 25 are pushed by the valve springs 26 and 27 toward the valve closing direction. Further, the cylinder head 13 is also provided with a Mars plug 23 whose front end faces the combustion chamber 17.

一併參考第3圖，前述進氣汽門24及前述排氣汽門25，是藉由收容在「形成於前述汽缸頭13與前述頭蓋14間之汽門驅動室28」的可變驅動汽門裝置29A所開閉驅 動，該可變驅動汽門裝置29A，是被配置在前述進氣汽門24與排氣汽門25間，並且具備：凸輪軸32，該凸輪軸32設有進氣凸輪30與排氣凸輪31；和異體凸輪33，該異體凸輪33的凸輪輪廓是不同於排氣凸輪31，並可在前述凸輪軸32的外周移動於軸方向上且安裝成不能相對旋轉；和減壓裝置34A，該減壓裝置34A是將前述排氣凸輪31挾持於其與前述異體凸輪33間，並安裝於前述凸輪軸32；和進氣側與排氣側擺動軸36、37，該進氣側與排氣側擺動軸36、37具有與前述凸輪軸32平行的軸線，且被汽缸頭14所支承；和進氣側搖臂38，該進氣側搖臂38是從動於前述進氣凸輪30，並用來驅動進氣汽門24開閉，且能自由搖動地被進氣側擺動軸36所支承；及排氣側搖臂39，該排氣側搖臂39是從動於前述排氣凸輪31、前述異體凸輪33或者前述減壓裝置34A的減壓凸輪35，並用來驅動排氣汽門25開閉，且可自由搖動地被排氣側擺動軸37所支承。Referring to FIG. 3 together, the intake valve 24 and the exhaust valve 25 are variable drive steam housed in a "valve drive chamber 28 formed between the cylinder head 13 and the head cover 14". Door device 29A is opened and closed The variable drive valve device 29A is disposed between the intake valve 24 and the exhaust valve 25, and is provided with a cam shaft 32 provided with an intake cam 30 and an exhaust cam And a foreign body cam 33 having a cam profile different from the exhaust cam 31 and movable in the axial direction on the outer circumference of the cam shaft 32 and mounted so as not to be relatively rotatable; and a pressure reducing device 34A, The decompression device 34A holds the exhaust cam 31 between the inter-body cam 33 and the camshaft 32, and the intake side and exhaust side swing shafts 36, 37, which are exhausted The side swinging shafts 36, 37 have an axis parallel to the aforementioned camshaft 32 and are supported by the cylinder head 14; and an intake side rocker arm 38 that is slaved to the aforementioned intake cam 30 and used The intake port 24 is driven to open and close, and is rotatably supported by the intake side swing shaft 36; and the exhaust side rocker arm 39 is driven by the exhaust cam 31, the foregoing The foreign body cam 33 or the pressure reducing cam 35 of the pressure reducing device 34A is used to drive the exhaust valve 25 to open and close, It is swingably supported by the exhaust-side pivot shaft 37.

前述汽缸頭13一體設有：第1支承部42，該第1支承部42具有第1軸承孔40；及第2支承部43，該第2支承部43具有與第1軸承孔40同軸的第2軸承孔41。前述凸輪軸32的其中一端部，是在與第1軸承孔40的內周之間夾介著作為第1軸承的第1滾珠軸承44，而可旋轉地由第1支承部42所支承，前述凸輪軸32之靠近另一端的部分，則可自由旋轉地貫穿第2軸承孔41，在第2軸承孔41的內周及凸輪軸32之間，夾設有作為第2軸承的第2 滾珠軸承45。而凸輪軸32是被壓入第1及第2滾珠軸承44、45的內輪，前述進氣凸輪30及前述排氣凸輪31則形成：將進氣凸輪30配置於第1滾珠軸承44側，並將排氣凸輪31配置於第2滾珠軸承45側，且在第1及第2滾珠軸承44、45間一體形成於前述凸輪軸32，前述減壓裝置34A是被配置在前述進氣凸輪30與前述排氣凸輪31之間，異體凸輪33，是在排氣凸輪31挾持於前述減壓裝置34A的減壓凸輪35之間的位置，安裝於前述凸輪軸32。The cylinder head 13 is integrally provided with a first support portion 42 having a first bearing hole 40 and a second support portion 43 having a coaxial portion with the first bearing hole 40. 2 bearing hole 41. One end portion of the cam shaft 32 is a first ball bearing 44 that is interposed between the first bearing and the inner circumference of the first bearing hole 40, and is rotatably supported by the first support portion 42. The portion of the cam shaft 32 near the other end is rotatably inserted through the second bearing hole 41, and the second bearing is interposed between the inner circumference of the second bearing hole 41 and the cam shaft 32. Ball bearing 45. The cam shaft 32 is an inner ring that is pressed into the first and second ball bearings 44 and 45. The intake cam 30 and the exhaust cam 31 are formed such that the intake cam 30 is disposed on the first ball bearing 44 side. The exhaust cam 31 is disposed on the second ball bearing 45 side, and is integrally formed between the first and second ball bearings 44 and 45 on the cam shaft 32. The pressure reducing device 34A is disposed on the intake cam 30. The foreign body cam 33 is attached to the cam shaft 32 at a position where the exhaust cam 31 is held between the pressure reducing cams 35 of the pressure reducing device 34A.

來自於圖面中未顯示之曲柄軸的旋轉力，是透過定時傳動機構(timing transmission mechanism)47而傳達至前述凸輪軸32，該定時傳動機構47，是將無間斷狀的凸輪鏈條50捲掛於：被固定在來自於前述凸輪軸32的第2滾珠軸承45之突出端部的從動鏈輪48、及被固設在前述曲柄軸的驅動鏈輪(圖面中未顯示)所形成，凸輪鏈條50是可行走地被收納於鏈條行走通路51內，該鏈條行走通路51是遍及汽缸體12、汽缸頭13及頭蓋14所形成。The rotational force from the crankshaft, not shown in the drawing, is transmitted to the camshaft 32 via a timing transmission mechanism 47 that winds the uninterrupted cam chain 50 The driven sprocket 48 fixed to the protruding end portion of the second ball bearing 45 of the cam shaft 32 and the drive sprocket (not shown) fixed to the crank shaft are formed. The cam chain 50 is slidably housed in the chain traveling path 51, and the chain traveling path 51 is formed throughout the cylinder block 12, the cylinder head 13, and the head cover 14.

檢視第1圖，前述進氣凸輪30及前述排氣凸輪31具有：圓弧狀的基圓部30a、31a，該圓弧狀的基圓部30a、31a是以前述凸輪軸32的軸線作為中心；及高位部30b、31b，該高位部30b、31b是較基圓部30a、31a更突出於外側方，且連結於基圓部30a、31a的周方向兩端之間；且前述進氣凸輪30及前述排氣凸輪31是藉由使高位部30b、31b的相位錯開，而一體地形成於前述凸輪軸32。In the first drawing, the intake cam 30 and the exhaust cam 31 have arc-shaped base portions 30a and 31a which are centered on the axis of the cam shaft 32. And the upper portions 30b and 31b, the upper portions 30b and 31b projecting outward from the base portions 30a and 31a, and are connected between the circumferential ends of the base portions 30a and 31a; and the intake cam The exhaust cam 31 and the exhaust cam 31 are integrally formed on the cam shaft 32 by shifting the phases of the upper portions 30b and 31b.

在被前述進氣側擺動軸36支承成可搖動的進氣側搖 臂38的其中一端部，軸支著滾動接觸於進氣凸輪30的滾子52，在該進氣側搖臂36的另一端部，抵接於進氣汽門24之桿身末端24a的挺桿螺絲53，是可調整進退位置地螺合。此外，在被前述進氣側擺動軸37支承成可搖動的進氣側搖臂39的其中一端部，軸支著滾動接觸於進氣凸輪31的滾子54，在該進氣側搖臂39的另一端部，抵接於進氣汽門25之桿身末端25a的挺桿螺絲55，是可調整進退位置地螺合。Supported by the aforementioned intake side swing shaft 36 as a swingable intake side shake One end of the arm 38, the shaft supports a roller 52 that is in rolling contact with the intake cam 30, and the other end of the intake side rocker arm 36 abuts against the shaft end 24a of the intake valve 24 The rod screw 53 is screwed in an adjustable forward and backward position. Further, at one end portion of the intake side rocker arm 39 supported by the aforementioned intake side swing shaft 37 to be rockable, the shaft supports a roller 54 that is in rolling contact with the intake cam 31, on which the rocker arm 39 is held The other end portion is a tappet screw 55 that abuts against the shaft end 25a of the intake valve 25, and is screwed in an adjustable forward and backward position.

前述滾子52、54沿著旋轉軸線的寬度，是被設定成大於前述進氣凸輪30及前述排氣凸輪31在沿著凸輪軸32軸線之方向上的寬度，滾子52、54是滾動接觸於：前述進氣凸輪30及前述排氣凸輪31在沿著凸輪軸32軸線之方向上的中央部。此外，前述滾子52、54被配置成：其中一部份在從凸輪軸32之軸線方向觀看的視角中形成重疊，且在滾子52、54間保持著特定的間隔，以避免滾子52、54相互干涉，進氣凸輪30及排氣凸輪31，也保持著對應於上述間隔的間隔，而設於凸輪軸32。The width of the rollers 52, 54 along the rotation axis is set to be larger than the width of the intake cam 30 and the exhaust cam 31 in the direction along the axis of the cam shaft 32, and the rollers 52, 54 are rolling contact. The intake cam 30 and the exhaust cam 31 are at a central portion in the direction along the axis of the cam shaft 32. Further, the aforementioned rollers 52, 54 are configured such that a portion thereof overlaps in a viewing angle viewed from the axial direction of the cam shaft 32, and a specific interval is maintained between the rollers 52, 54 to avoid the roller 52. The air is in contact with each other, and the intake cam 30 and the exhaust cam 31 are also provided on the cam shaft 32 while maintaining an interval corresponding to the above-described interval.

不僅如此，在前述排氣側搖臂39的其中一端部，可抵接於前述異體凸輪33的抵接部39a、及可抵接於前述減壓裝置34A之減壓凸輪35的抵接部39b，是將前述滾子54挾持於其間而設成一體，兩抵接部39a、39b至少在凸輪軸32側的端部形成：從沿著凸輪軸32軸線的方向觀看，與前述滾子54的外周一致、或者較前述外周更突出於前述凸輪軸32側。In addition, one end portion of the exhaust side rocker arm 39 can abut against the abutting portion 39a of the deformed cam 33 and the abutting portion 39b of the decompression cam 35 that can abut against the decompressing device 34A. The roller 54 is held integrally by being held therebetween, and the abutting portions 39a and 39b are formed at least at the end on the cam shaft 32 side: viewed from the direction along the axis of the cam shaft 32, and the roller 54 The outer circumference is uniform or protrudes from the camshaft 32 side more than the outer circumference.

前述異體凸輪33，可在：接近前述排氣凸輪31且抵接於排氣側搖臂39之抵接部39a的作動位置(第3圖中以實線表示的位置)、及從前述排氣凸輪31分離而避免與前述排氣側搖臂39之抵接部39a抵接的非作動位置(第3圖中以虛線表示的位置)間，移動於前述凸輪軸32的軸線方向上，並在凸輪軸32的外周嵌裝成無法對該凸輪軸32的軸線週圍形成轉動。The foreign body cam 33 is close to the exhaust cam 31 and abuts against an actuating position (a position indicated by a solid line in FIG. 3) of the abutting portion 39a of the exhaust side rocker arm 39, and the exhaust gas The cam 31 is separated from the non-actuated position (a position indicated by a broken line in FIG. 3) that abuts against the abutting portion 39a of the exhaust side rocker arm 39, and moves in the axial direction of the cam shaft 32, and The outer circumference of the cam shaft 32 is fitted so as not to be rotatable around the axis of the cam shaft 32.

一併參考第4圖，前述異體凸輪33，是用來驅動前述排氣汽門25開啟汽門的排放氣體再循環用凸輪，可使由燃燒室17所排出之排放氣體的一部份回到燃燒室17，其具有：將前述凸輪軸32的軸線作為中心的圓弧狀基圓部33a、及從基圓部33a朝外側方突出的高位部33b，異體凸輪33的基圓部33a，是形成較排氣凸輪31的基圓部31a更小的外徑。Referring to Fig. 4, the aforementioned foreign body cam 33 is a discharge gas recirculation cam for driving the exhaust valve 25 to open the valve, and a part of the exhaust gas discharged from the combustion chamber 17 can be returned. The combustion chamber 17 has an arc-shaped base portion 33a having the axis of the cam shaft 32 as a center, and a high portion 33b protruding outward from the base portion 33a. The base portion 33a of the variant cam 33 is A smaller outer diameter than the base circular portion 31a of the exhaust cam 31 is formed.

此外，高位部33b，是在對應於進氣凸輪30中高位部30b之關閉汽門末期的相位，從前述基圓部33a略微突出的部分，高位部33b之周方向兩端是形成圓滑的曲線並連接於前述基圓部33a。而當異體凸輪33移動至「抵接於排氣側搖臂39之抵接部39a」的作動位置時，排氣側搖臂39在藉由排氣凸輪31的高位部31b產生轉動而促使排氣汽門25執行關閉汽門的動作後，是藉由抵接於排氣凸輪31的基圓部31a而保持關閉汽門的狀態，但進氣汽門24在關閉汽門作動時的末期，是如第5圖所示，由異體凸輪33的高位部33b使排氣側搖臂39產生些微的轉動進而促 使排氣汽門25些微地開啟汽門。如此一來，可在壓縮行程中使排氣汽門25暫時開啟，而由排放氣體促使混合氣在燃燒室17內之燃燒的活性化，可達成NOx排出量的減少、引擎輸出的提升及燃料費的降低等。Further, the upper portion 33b is a portion which protrudes slightly from the base portion 33a in a phase corresponding to the end of the closing portion of the upper portion 30b of the intake cam 30, and the circumferential portion of the upper portion 33b forms a smooth curve. And connected to the aforementioned base round portion 33a. When the foreign body cam 33 moves to the actuating position of "abutting against the abutting portion 39a of the exhaust side rocker arm 39", the exhaust side rocker arm 39 is caused to rotate by the rotation of the upper portion 31b of the exhaust cam 31. After the gas valve 25 performs the operation of closing the valve, the state in which the valve is closed is maintained by abutting against the base portion 31a of the exhaust cam 31, but the intake valve 24 is at the end of the valve actuation. As shown in Fig. 5, the exhaust side rocker arm 39 is slightly rotated by the upper portion 33b of the foreign body cam 33. The exhaust valve 25 is caused to open the valve slightly. In this way, the exhaust valve 25 can be temporarily opened during the compression stroke, and the combustion of the mixed gas in the combustion chamber 17 can be activated by the exhaust gas, thereby achieving a reduction in the amount of NOx emissions, an increase in engine output, and fuel. The fee is reduced, etc.

另外，當異體凸輪33移動至避免與排氣側搖臂39之抵接部39a接觸的位置時，排氣側搖臂39僅由排氣凸輪31所驅動轉動，排氣汽門25是以對應於排氣凸輪31之凸輪輪廓的作動態樣進行開閉動作。換言之，可藉由異體凸輪33沿著凸輪軸32軸線的移動而切換：對應於排氣凸輪31之凸輪輪廓的排氣汽門25的開閉作動態樣；及在對應於排氣凸輪31之凸輪輪廓的開閉作動狀態下，形成「可在於原本關閉汽門期間獲得暫時開啟汽門之狀態」的排氣汽門25的作動態樣。Further, when the foreign body cam 33 is moved to a position avoiding contact with the abutting portion 39a of the exhaust side rocker arm 39, the exhaust side rocker arm 39 is only driven to rotate by the exhaust cam 31, and the exhaust valve 25 is corresponding The opening and closing operation is performed on the dynamic profile of the cam profile of the exhaust cam 31. In other words, it can be switched by the movement of the foreign body cam 33 along the axis of the camshaft 32: the opening and closing of the exhaust valve 25 corresponding to the cam profile of the exhaust cam 31 as a dynamic sample; and the cam corresponding to the exhaust cam 31 In the opening and closing state of the contour, a dynamic example of the exhaust valve 25 that "can be temporarily opened by the valve during the closing of the valve" is formed.

中心孔57是在前述凸輪軸32及前述從動鏈輪48設成同軸，在凸輪軸32的其中一端部，同軸地螺鎖著用來封閉前述中心孔57之一端部的螺栓58。此外，在其中一端部同軸地具有面向前述螺栓58之小徑軸部59Aa的桿59A，是可在軸方向上移動且同軸地***前述中心孔57，而桿59A的另一端是從前述從動鏈輪48突出。The center hole 57 is coaxial with the cam shaft 32 and the driven sprocket 48. At one end portion of the cam shaft 32, a bolt 58 for closing one end portion of the center hole 57 is coaxially screwed. Further, the rod 59A having the one end portion coaxially facing the small diameter shaft portion 59Aa of the bolt 58 is movable in the axial direction and coaxially inserted into the center hole 57, and the other end of the rod 59A is driven from the foregoing The sprocket 48 protrudes.

此外，在配置有異體凸輪33的部分，是於前述凸輪軸32設有「連結於前述中心孔57的內周面與前述凸輪軸32的外周面間，且在前述凸輪軸32的軸方向上長距離延伸」的導引孔60。而在該實施形態中，如第4圖所示，具有垂直於前述中心孔57軸線C之軸線的一對導引孔60、 60，是被設於凸輪軸32，而可移動於軸方向且被安裝於凸輪軸32外周的前述異體凸輪33及前述桿59A，是由單一連結銷61所連結，該連結銷61可在貫穿前述導引孔60...的狀態下，在導引孔60...內滑動於沿著前述軸線C的方向上。Further, in the portion in which the foreign body cam 33 is disposed, the cam shaft 32 is provided "connected between the inner circumferential surface of the center hole 57 and the outer circumferential surface of the cam shaft 32, and in the axial direction of the cam shaft 32. A guide hole 60 that extends over a long distance. In this embodiment, as shown in FIG. 4, a pair of guiding holes 60 having an axis perpendicular to the axis C of the center hole 57, 60 is a camshaft 32 that is movable in the axial direction and is attached to the outer circumference of the camshaft 32, and is connected to the rod 59A by a single coupling pin 61. The coupling pin 61 can be penetrated. In the state of the aforementioned guide holes 60, the guide holes 60 are slid in the direction along the aforementioned axis C.

如此一來，異體凸輪33形成：在不會對凸輪軸32之軸線周圍產生相對轉動的狀態下，可在「接近排氣凸輪31並抵接於排氣側搖臂39之抵接部39a」的作動位置、及「從排氣凸輪31分離，而避免抵接於排氣側搖臂39之抵接部39a」的非作動位置之間，移動於前述凸輪軸32的軸線方向上，且被嵌裝於該凸輪軸32的外周。In this manner, the foreign body cam 33 is formed to "close to the exhaust cam 31 and abut against the abutting portion 39a of the exhaust side rocker arm 39 in a state where the relative rotation of the axis of the cam shaft 32 is not caused." The actuating position and the non-actuating position of "separating from the exhaust cam 31 to avoid abutting against the abutting portion 39a of the exhaust side rocker arm 39" are moved in the axial direction of the cam shaft 32, and are The outer circumference of the cam shaft 32 is fitted.

在前述桿59A與前述螺栓58間縮設有線圈狀的回動彈簧(return spring)62，該線圈狀的回動彈簧(return spring)62圍繞著前述桿59A的小徑軸部59Aa，桿59A則是被前述回動彈簧62彈推至「使前述異體凸輪33成為非作動位置」的那一側。A coil-shaped return spring 62 is retracted between the rod 59A and the bolt 58. The coil-shaped return spring 62 surrounds the small-diameter shaft portion 59Aa of the rod 59A, and the rod 59A Then, the return spring 62 is pushed to the side where "the above-described foreign body cam 33 is in the non-actuated position".

前述桿59A，是可促使前述異體凸輪33在非作動位置與作動位置之間移動，並由桿驅動手段63朝軸方向驅動的構件，該桿驅動手段63具備：電磁閥64，該電磁閥64是由複數支螺栓68、68...安裝於汽缸頭13的側壁；及轉動撥桿67，該轉動撥桿67的基端部是透過支軸66而可自由轉動地由前述汽缸頭13所支承，且前端部抵接於前述桿59A的另一端，前述電磁閥64所具備之輸出軸65的前端，具有與前述凸輪軸32平行的軸線，且從前桿59A 的相反側抵接於前述轉動撥桿67。The rod 59A is a member that urges the foreign body cam 33 to move between the non-actuated position and the actuating position, and is driven in the axial direction by the rod driving means 63. The rod driving means 63 is provided with a solenoid valve 64. The solenoid valve 64 is provided. It is mounted on the side wall of the cylinder head 13 by a plurality of bolts 68, 68... and a rotary lever 67. The base end portion of the rotary lever 67 is rotatably driven by the cylinder head 13 through the support shaft 66. The front end portion abuts against the other end of the rod 59A, and the front end of the output shaft 65 of the electromagnetic valve 64 has an axis parallel to the cam shaft 32, and the front rod 59A The opposite side abuts against the aforementioned turning lever 67.

根據上述的桿驅動手段63，當電磁閥64作動至使輸出軸65突出的那一側時，轉動撥桿67將克服回動彈簧62的彈簧力而朝第2圖及第4圖的順時針方向轉動，並克服回動彈簧62的彈簧力後將桿59A壓入，使得異體凸輪33移動至「接近排氣凸輪31，且抵接於排氣側搖臂39之抵接部39a」的作動位置，在電磁閥64的非作動狀態下，異體凸輪33是藉由回動彈簧62的彈簧力，而移動至「從排氣凸輪31分離，而避免抵接於排氣側搖臂39之抵接部39a」的非作動位置。According to the above-described lever driving means 63, when the solenoid valve 64 is actuated to the side where the output shaft 65 protrudes, the rotary lever 67 will overcome the spring force of the return spring 62 toward the clockwise of Figs. 2 and 4. When the direction is rotated and the spring force of the return spring 62 is overcome, the rod 59A is pushed in, so that the foreign body cam 33 is moved to "actuate to the exhaust cam 31 and abut against the abutting portion 39a of the exhaust side rocker arm 39". Position, in the non-actuated state of the solenoid valve 64, the foreign body cam 33 is moved by the spring force of the return spring 62 to "separate from the exhaust cam 31, and avoid contact with the exhaust side rocker arm 39" The non-actuated position of the joint 39a".

一併參考第6圖及第7圖，減壓裝置34A，是為了降低引擎啟動時的排氣壓力以便於容易啟動，而在引擎旋轉數、也就是指凸輪軸32的旋轉數較低的狀態下，促使排氣汽門25在原本關閉的時間點些微地開啟汽門的裝置，該減壓裝置34A具備：減壓配重72，該減壓配重72是透過具有與凸輪軸32平行之軸線的減壓銷71A，而可轉動地由進氣凸輪30與排氣凸輪31所支承；及減壓凸輪35，該減壓凸輪35是在低引擎旋轉數的狀態下，從排氣凸輪31的基圓部31a突出，並藉由隨著「抵接於排氣側搖臂39之抵接部39b的凸輪軸32朝第6圖的箭號73所指示的方向旋轉」所產生的離心力作用，在減壓配重72轉動時不會抵接於前述排氣側搖臂39的抵接部39b，且連結於減壓配重72，該減壓裝置34A被配置於進氣凸輪30與排氣凸輪31之間，且由進氣凸輪30與排氣凸輪31所支承。Referring to Figures 6 and 7, the pressure reducing device 34A is for reducing the exhaust pressure at the start of the engine to facilitate easy starting, and the number of engine revolutions, that is, the number of rotations of the cam shaft 32 is low. The means for causing the exhaust valve 25 to slightly open the valve at a time when the exhaust valve 25 is closed is provided. The decompression device 34A is provided with a decompression weight 72 which is transmitted through the parallel with the cam shaft 32. The decompression pin 71A of the axis is rotatably supported by the intake cam 30 and the exhaust cam 31; and the decompression cam 35 is in a state of low engine rotation number from the exhaust cam 31 The base circular portion 31a protrudes and acts by centrifugal force generated by "rotation of the cam shaft 32 abutting against the abutting portion 39b of the exhaust side rocker arm 39 toward the direction indicated by the arrow 73 of Fig. 6". When the decompression weight 72 rotates, it does not abut against the abutting portion 39b of the exhaust side rocker arm 39, and is coupled to the decompression weight 72, and the decompression device 34A is disposed on the intake cam 30 and the row. The air cams 31 are supported by the intake cams 30 and the exhaust cams 31.

減壓配重72，是從側方覆蓋凸輪軸32的略半周而形成圓弧狀，且其中一面的局部滑接於凸輪軸32的進氣凸輪30，並被配置於進氣凸輪30與排氣凸輪31之間，該減壓配重72的其中一端，是被配置成對應於前述凸輪軸32之排氣凸輪31的高位部31b。不僅如此，在減壓配重72的其中一端部面對前述排氣凸輪31之那一側的面上，設有朝排氣凸輪31側開放的圓形收容凹部74，在該收容凹部74嵌合著圓筒狀支承突座75的其中一端部。此外，在支承突座75的另一端，突出於半徑方向外側的鍔部75a，是與支承突座75的另一端面連接成同一平面地設成一體，支承突座75的另一端是抵接於前述凸輪軸32之排氣凸輪31的高位部31b。The decompression weight 72 is formed in an arc shape by covering a slight half of the cam shaft 32 from the side, and a part of one side is slidably coupled to the intake cam 30 of the cam shaft 32, and is disposed on the intake cam 30 and the row. Between the air cams 31, one end of the decompression weight 72 is a high portion 31b that is disposed to correspond to the exhaust cam 31 of the cam shaft 32. In addition, a circular receiving recess 74 that is open toward the exhaust cam 31 side is provided on a surface of the one end portion of the decompression weight 72 that faces the exhaust cam 31, and the receiving recess 74 is embedded in the receiving recess 74. One end portion of the cylindrical support protrusion 75 is joined. Further, at the other end of the support protrusion 75, the flange portion 75a protruding outward in the radial direction is integrally formed in the same plane as the other end surface of the support protrusion 75, and the other end of the support protrusion 75 is abutted. The upper portion 31b of the exhaust cam 31 of the cam shaft 32 is provided.

前述減壓銷71A，是從進氣凸輪30側貫穿該進氣凸輪30、減壓配重72、前述支承突座75及前述排氣凸輪31，在進氣凸輪30設有可供前述減壓銷71A貫穿的第1貫穿孔76，在前述減壓配重72的其中一端部，可供前述減壓銷71A貫穿的第2貫穿孔77是同軸地連通於前述收容凹部74而設置，在前述排氣凸輪31的高位部31b，可供前述減壓銷71A***的盲孔78是被設成：與前述第1及第2貫穿孔76、77同軸，且朝前述進氣凸輪30側開放。The decompression pin 71A penetrates the intake cam 30, the decompression weight 72, the support protrusion 75, and the exhaust cam 31 from the intake cam 30 side, and the intake cam 30 is provided with the decompression. The first through hole 76 through which the pin 71A is inserted is provided at one end portion of the decompression weight 72, and the second through hole 77 through which the decompression pin 71A can pass is coaxially communicated with the housing recess 74. The upper portion 31b of the exhaust cam 31 is provided with a blind hole 78 into which the decompression pin 71A is inserted, and is coaxial with the first and second through holes 76 and 77, and is open toward the intake cam 30 side.

而減壓銷71A，是從進氣凸輪30側貫穿該進氣凸輪30的第1貫穿孔76、減壓配重72的第2貫穿孔77、支承突座75與排氣凸輪31的貫穿孔78，如此一來，減壓配重72的其中一端部，是透過被進氣凸輪30與排氣凸輪31雙 方所支承的減壓銷71A，而可轉動地被進氣凸輪30與排氣凸輪31所支承。The decompression pin 71A is a first through hole 76 that penetrates the intake cam 30 from the intake cam 30 side, a second through hole 77 that decompresses the weight 72, and a through hole that supports the protrusion 75 and the exhaust cam 31. 78. In this way, one end portion of the decompression weight 72 is transmitted through the intake cam 30 and the exhaust cam 31 The decompression pin 71A supported by the side is rotatably supported by the intake cam 30 and the exhaust cam 31.

不僅如此，在其中一端部抵接於前述貫穿孔78之閉塞端的前述減壓銷71A的另一端，是藉由抵接於墊圈79的外周部，而阻止從減壓銷71A的前述第1貫穿孔76、第2貫穿孔77、支承突座75與貫穿孔78離脫。換言之，內周部被挾持於「可將前述第1滾珠軸承44與進氣凸輪30間的間隔保持一定的第1滾珠軸承44的內輪44a與凸輪軸32間」之墊圈79的外周部，是抵接於進氣凸輪30，故可以不需要「使該墊圈79的外周抵接於前述減壓銷71A的另一端，用來決定減壓銷71A之軸方向位置」的專用構件。Further, the other end of the decompression pin 71A at which one end portion abuts against the closing end of the through hole 78 is prevented from abutting from the outer peripheral portion of the washer 79 by the first through portion of the decompression pin 71A. The hole 76, the second through hole 77, and the support protrusion 75 are separated from the through hole 78. In other words, the inner peripheral portion is held by the outer peripheral portion of the washer 79 between the inner wheel 44a and the cam shaft 32 of the first ball bearing 44 that can maintain a constant interval between the first ball bearing 44 and the intake cam 30. Since it is in contact with the intake cam 30, it is not necessary to use a dedicated member for "abutting the outer circumference of the washer 79 against the other end of the decompression pin 71A and determining the axial position of the decompression pin 71A".

此外，圍繞著前述支承突座75之線圈狀扭力彈簧80的其中一端部，是卡合於設在前述凸輪軸32的有底卡合孔81，而扭力彈簧80的另一端部，是卡合在設於前述減壓配重72之其中一端部的卡合孔82。藉由該扭力彈簧80的彈簧力，而將減壓配重72彈推至：使該減壓配重72的中間部接近凸輪軸32外周面的那一側。Further, one end portion of the coil-shaped torsion spring 80 surrounding the support protrusion 75 is engaged with the bottomed engagement hole 81 provided in the cam shaft 32, and the other end portion of the torsion spring 80 is engaged. An engaging hole 82 provided at one end portion of the pressure reducing weight 72 is provided. By the spring force of the torsion spring 80, the decompression weight 72 is pushed to the side where the intermediate portion of the decompression weight 72 is close to the outer circumferential surface of the cam shaft 32.

前述減壓凸輪35，是在對應於排氣凸輪31之基圓部31a的位置，被配置於前述減壓配重72的另一端側與前述排氣凸輪31之間的構件，且可轉動地由植設於前述排氣凸輪31的減壓凸輪軸84所支承。而減壓凸輪軸84，是具有與凸輪軸32的軸線平行之軸線的構件，減壓凸輪35可在與凸輪軸32之軸線平行的軸線周圍轉動，且被凸輪軸 32所支承。The decompression cam 35 is a member that is disposed between the other end side of the decompression weight 72 and the exhaust cam 31 at a position corresponding to the base circular portion 31a of the exhaust cam 31, and is rotatably It is supported by a decompression camshaft 84 that is implanted in the exhaust cam 31. The decompression camshaft 84 is a member having an axis parallel to the axis of the camshaft 32, and the decompression cam 35 is rotatable about an axis parallel to the axis of the camshaft 32, and is camshaft 32 supports.

雖然前述減壓凸輪35，基本上是形成與前述減壓凸輪軸84同軸的圓柱狀，但該減壓凸輪35之前述排氣凸輪31側的局部，是被切割而形成與減壓凸輪35之軸線平行的平面部85。換言之，減壓凸輪35之排氣凸輪31側的外周是形成由以下構件所構成：將減壓凸輪軸84的軸線作為中心的圓弧部86、及連結於該圓弧部86的周方向兩端間的前述平面部85，該減壓凸輪35可在以下的兩種狀態間轉動：如第6圖所示，使較前述排氣凸輪31的基圓部31a位於更內側的前述平面部85面向外側的減壓停止狀態；及如第8圖所示，使前述圓弧部86的一部分較前述排氣凸輪31的基圓部31a更突出於外側的減壓啟動狀態。The decompression cam 35 basically has a cylindrical shape coaxial with the decompression camshaft 84. However, a portion of the decompression cam 35 on the side of the exhaust cam 31 is cut and formed with the decompression cam 35. A flat portion 85 whose axes are parallel. In other words, the outer circumference of the decompression cam 35 on the side of the exhaust cam 31 is formed by a circular arc portion 86 having the axis of the decompression camshaft 84 as a center, and two circumferential directions connected to the arcuate portion 86. The flat portion 85 between the ends, the decompression cam 35 is rotatable between two states: as shown in Fig. 6, the flat portion 85 which is located further inside than the base portion 31a of the exhaust cam 31 is provided The decompression stop state facing the outer side; and as shown in Fig. 8, a part of the arc portion 86 is protruded from the base circle portion 31a of the exhaust cam 31 to the outside in a decompression start state.

而當減壓凸輪35的圓弧部86從前述基圓部31a朝外側突出時，藉由使排氣側搖臂39的抵接部39b抵接於圓弧部86，可使排氣側搖臂39轉動，而促使排氣汽門25些微地開啟汽門。When the arc portion 86 of the decompression cam 35 protrudes outward from the base portion 31a, the exhaust portion can be shaken by abutting the abutting portion 39b of the exhaust side rocker arm 39 against the arc portion 86. The arm 39 rotates to cause the exhaust valve 25 to slightly open the valve.

在前述減壓配重72的另一端部，壓入著「具有與凸輪軸32平行之軸線」的連結銷87，可供「來自於該連結銷87之減壓配重72的突出部」嵌合的導引溝88，是沿著減壓凸輪35的半徑方向延伸，而設於該減壓凸輪35之減壓配重72側的部分。由於凸輪軸32的旋轉數較大而使作用於減壓配重72的離心力較大，在減壓配重72反抗前述扭力彈簧80的彈推力而轉動並促使該減壓配重72的中間部從凸輪軸32的外周分離的減壓停止狀態中，如第6圖 所示，嵌合於導引溝88的連結銷87與減壓配重72一起轉動，在狀態下的減壓凸輪35，該平面部85是位在：在較前述排氣凸輪31的基圓部31a更內側，且面臨外側的轉動位置，排氣側搖臂39的抵接部39b並不會抵接於減壓凸輪35，且排氣側搖臂39追隨著排氣凸輪31的凸輪輪廓而搖動，排氣汽門25也追隨著排氣凸輪31之凸輪輪廓的時間點進行開閉作動。此外，由於凸輪軸32的旋轉數較小而使作用於減壓配重72的離心力較小，在減壓配重72藉由前述扭力彈簧80的彈推力而轉動並促使該減壓配重72的中間部接近凸輪軸32外周的減壓啟動狀態中，如第8圖所示，嵌合於導引溝88的連結銷87是與減壓凸輪35一起轉動，該狀態下的減壓凸輪35，該圓弧部86的一部分是位在：從前述排氣凸輪31的基圓部31a朝外側突出的轉動位置，由於排氣側搖臂39的抵接部39b抵接於減壓凸輪35的圓弧部86，因此排氣側搖臂39在滾子54接觸於排氣凸輪31之基圓部31a的時間點，藉由前述減壓凸輪35而略為搖動，排氣汽門25是形成：無視於排氣凸輪31的凸輪輪廓，而在關閉汽門的時間點些微地開啟汽門。At the other end of the decompression weight 72, a coupling pin 87 "having an axis parallel to the cam shaft 32" is press-fitted, and the "protrusion from the decompression weight 72 of the coupling pin 87" is embedded. The guide groove 88 is a portion extending along the radial direction of the decompression cam 35 and provided on the decompression weight 72 side of the decompression cam 35. Since the centrifugal force of the decompression weight 72 is large due to the large number of rotations of the cam shaft 32, the decompression weight 72 rotates against the spring force of the torsion spring 80 to urge the intermediate portion of the decompression weight 72. In the decompression stop state separated from the outer circumference of the camshaft 32, as shown in FIG. As shown, the coupling pin 87 fitted to the guide groove 88 rotates together with the decompression weight 72, and the decompression cam 35 in the state is located at a base circle smaller than the aforementioned exhaust cam 31. The portion 31a is further inside and faces the outer rotational position, the abutting portion 39b of the exhaust side rocker arm 39 does not abut against the decompression cam 35, and the exhaust side rocker arm 39 follows the cam profile of the exhaust cam 31 On the other hand, the exhaust valve 25 is also opened and closed in accordance with the time point of the cam profile of the exhaust cam 31. Further, since the centrifugal force acting on the decompression weight 72 is small due to the small number of rotations of the cam shaft 32, the decompression weight 72 is rotated by the spring force of the torsion spring 80 and urges the decompression weight 72. In the decompression start state in which the intermediate portion is close to the outer circumference of the cam shaft 32, as shown in Fig. 8, the coupling pin 87 fitted to the guide groove 88 is rotated together with the decompression cam 35, and the decompression cam 35 in this state is rotated. A part of the circular arc portion 86 is located at a rotational position that protrudes outward from the base circular portion 31a of the exhaust cam 31, and the abutting portion 39b of the exhaust-side rocker arm 39 abuts against the decompression cam 35. Since the arc portion 86 is disposed, the exhaust side rocker arm 39 is slightly rocked by the decompression cam 35 at the time when the roller 54 contacts the base circle portion 31a of the exhaust cam 31, and the exhaust valve 25 is formed: The cam profile of the exhaust cam 31 is ignored, and the valve is slightly opened at the time of closing the valve.

除此之外，在減壓停止時，排氣汽門25開啟汽門的時間點，是如第5圖所示，被設定在：在由異體凸輪33促使排氣汽門25開啟汽門之時間點的附近，且從該時間點略為偏移的相位。In addition, when the decompression is stopped, the timing at which the exhaust valve 25 opens the valve is set as shown in Fig. 5: the exhaust valve 25 is caused to open the valve by the foreign body cam 33. A phase that is slightly offset from the point in time.

接著、說明該第1實施形態的作用，由於凸輪輪廓不 同於排氣凸輪31的異體凸輪33可切換：使排氣側搖臂39從動於排氣凸輪31的狀態、及使與凸輪軸32一起旋轉的異體凸輪33從動於前述排氣側搖臂39的狀態，且是在排氣凸輪31被挾持於與減壓凸輪35之間的位置，被安裝於凸輪軸32，因此可一起使用減壓裝置34A與異體凸輪33而促使排氣汽門25的汽門驅動特性有多樣的變化，且能使可變驅動汽門裝置29A構成小型化。Next, the action of the first embodiment will be described, since the cam profile is not The foreign body cam 33 of the same as the exhaust cam 31 can be switched between a state in which the exhaust side rocker arm 39 is driven by the exhaust cam 31, and a movement of the foreign body cam 33 that rotates together with the cam shaft 32. The state of the arm 39 is attached to the cam shaft 32 at a position where the exhaust cam 31 is held between the decompression cam 35, so that the decompression device 34A and the foreign body cam 33 can be used together to urge the exhaust valve There are various variations in the valve drive characteristics of 25, and the variable drive valve device 29A can be miniaturized.

此外，由於在透過第1與第2滾珠軸承44、45而可自由旋轉地支承於汽缸頭13的前述凸輪軸32，設有被配置於第1與第2滾珠軸承44、45之間的進氣凸輪30及排氣凸輪31，且減壓裝置34A被配置於進氣凸輪30與排氣凸輪31之間，故能有效地利用進氣凸輪30與排氣凸輪31間的空間來配置減壓裝置34A，並可藉由減壓裝置34A的配置而避免凸輪軸32之軸長度增加。In addition, the cam shaft 32 rotatably supported by the cylinder head 13 through the first and second ball bearings 44 and 45 is provided between the first and second ball bearings 44 and 45. Since the air cam 30 and the exhaust cam 31 are disposed between the intake cam 30 and the exhaust cam 31, the space between the intake cam 30 and the exhaust cam 31 can be effectively used to dispose the pressure. The device 34A can avoid an increase in the axial length of the camshaft 32 by the configuration of the pressure reducing device 34A.

除此之外，由於減壓裝置34A是被進氣凸輪30與排氣凸輪31所支承，因此能以兩端支承的構造穩定地支承減壓裝置34A。In addition, since the decompression device 34A is supported by the intake cam 30 and the exhaust cam 31, the decompression device 34A can be stably supported by the structure supported at both ends.

不僅如此，由於在前述凸輪軸32設有：中心孔57，該中心孔57是與凸輪軸32同軸地延伸；及導引孔60，該導引孔60連結於中心孔57的內周面與凸輪軸32的外周面間，且在凸輪軸32的軸方向上長距離延伸，而「可移動於軸方向上，且同軸地***中心孔57內」的桿59A、及「可移動於軸方向上且被安裝於凸輪軸32外周」的異體凸輪33，是由貫穿導引孔60的連結銷61所連結；在「 能使排氣側搖臂39從動於排氣凸輪31的異體凸輪33，從排氣凸輪31隔離」的非作動位置、與「能使排氣側搖臂39從動於異體凸輪33的異體凸輪33，接近排氣凸輪31」的作動位置之間，於軸方向上驅動桿59A的桿驅動手段63是連結於桿59A，因此，能以「利用桿驅動手段63在軸方向上驅動桿59A」的簡易構造，來切換「使排氣側搖臂39從動於排氣凸輪31」的狀態、以及「使排氣側搖臂39從動於異體凸輪33」的狀態，由於異體凸輪33通常是與凸輪軸32一起旋轉，故能抑制切換作動時之敲擊聲的產生，此外，可藉由將桿59A收容於凸輪軸32內，避免凸輪軸32的大型化。Moreover, since the cam shaft 32 is provided with a center hole 57, the center hole 57 extends coaxially with the cam shaft 32, and a guide hole 60 which is coupled to the inner circumferential surface of the center hole 57 and A rod 59A extending between the outer peripheral surfaces of the cam shaft 32 and extending in the axial direction of the cam shaft 32, and "movable in the axial direction and coaxially inserted into the center hole 57" and "movable in the axial direction" The foreign body cam 33 that is attached to the outer circumference of the cam shaft 32 is connected by the coupling pin 61 that penetrates the guide hole 60; The non-actuated position that can separate the exhaust-side rocker arm 39 from the dissimilar cam 33 of the exhaust cam 31 from the exhaust cam 31 and the "displacement of the exhaust-side rocker arm 39 from the foreign body cam 33" When the cam 33 is close to the operating position of the exhaust cam 31", the lever driving means 63 for driving the lever 59A in the axial direction is coupled to the lever 59A. Therefore, the lever 59A can be driven in the axial direction by the lever driving means 63. In the simple structure, the state in which "the exhaust side rocker arm 39 is driven by the exhaust cam 31" and the state in which the exhaust side rocker arm 39 is driven by the foreign body cam 33 are switched, and the foreign body cam 33 is normally Since the cam shaft 32 rotates together, it is possible to suppress the occurrence of the knocking sound during the switching operation, and the rod 59A can be accommodated in the cam shaft 32 to prevent the cam shaft 32 from being enlarged.

此外，由於異體凸輪33，用來驅動前述排氣汽門25，而使燃燒室17所排出之排放氣體的一部份回到燃燒室17的排放氣體再循環用凸輪，且該異體凸輪33是被配置在排氣凸輪31與第2軸承45之間，因此凸輪軸32是藉由進氣凸輪30與排氣凸輪31兩側的第1及第2滾珠軸承44、45而可自由旋轉地支承於汽缸頭，藉此既能良好地對凸輪軸32軸支承，又能配置異體凸輪32。Further, since the foreign body cam 33 is used to drive the exhaust valve 25, a part of the exhaust gas discharged from the combustion chamber 17 is returned to the exhaust gas recirculation cam of the combustion chamber 17, and the foreign body cam 33 is Since it is disposed between the exhaust cam 31 and the second bearing 45, the cam shaft 32 is rotatably supported by the first and second ball bearings 44 and 45 on both sides of the intake cam 30 and the exhaust cam 31. In the cylinder head, the camshaft 32 can be pivotally supported and the camshaft 32 can be disposed.

第9圖是顯示本發明的參考實施形態，為對應於前述實施形態之第3圖的剖面圖。Figure 9 is a cross-sectional view showing a reference embodiment of the present invention, which corresponds to the third embodiment of the above embodiment.

而對應於前述實施形態的部分僅標示相同的參考圖號來表示，並省略其詳細的說明。The parts corresponding to the foregoing embodiments are denoted by the same reference numerals, and the detailed description thereof will be omitted.

進氣汽門24與排氣汽門25，是由「被收容在形成於汽缸頭13與頭蓋14之間的汽門驅動室28」的可變驅動汽 門裝置29B所開閉驅動，該可變驅動汽門裝置29B具備：凸輪軸32，該凸輪軸32被配置在前述進氣汽門24與排氣汽門25之間，並且設有進氣凸輪30與排氣凸輪31；和異體凸輪33，該異體凸輪33的凸輪輪廓不同於排氣凸輪31，並可移動移軸方向且不能相對旋轉地安裝於前述凸輪軸32的外周；和減壓裝置34B，該減壓裝置34B是被安裝於前述凸輪軸32，而使前述排氣凸輪31被挾持於其與前述異體凸輪33之間；和進氣側與排氣側擺動軸36、37，該進氣側與排氣側擺動軸36、37是被支承於汽缸頭14而具有與前述凸輪軸32平行的軸線；和進氣側搖臂38，該進氣側搖臂38是可自由搖動地支承於進氣側擺動軸36，而從動於前述進氣凸輪30，並驅動進氣汽門24；及排氣側搖臂39，該排氣側搖臂39是可自由搖動地支承於排氣側擺動軸37，而從動於具有前述排氣凸輪31、前述異體凸輪33或前述減壓裝置34B的減壓凸輪35，並驅動排氣汽門25開閉。The intake valve 24 and the exhaust valve 25 are variable drive steam "retained in the valve drive chamber 28 formed between the cylinder head 13 and the head cover 14" The door device 29B is driven to open and close. The variable drive valve device 29B is provided with a cam shaft 32 disposed between the intake valve 24 and the exhaust valve 25, and is provided with an intake cam 30. And an exhaust cam 31; and a foreign body cam 33 having a cam profile different from that of the exhaust cam 31, and movable in a shifting shaft direction and not rotatably mounted to an outer circumference of the camshaft 32; and a pressure reducing device 34B The pressure reducing device 34B is attached to the cam shaft 32 such that the exhaust cam 31 is held between the camshaft 33 and the external cam 33; and the intake side and the exhaust side swing shaft 36, 37. The gas side and exhaust side swing shafts 36, 37 are supported by the cylinder head 14 and have an axis parallel to the cam shaft 32; and an intake side rocker arm 38 that is rotatably supported The intake side swing shaft 36 is driven by the intake cam 30 and drives the intake valve 24; and the exhaust side rocker arm 39 is rotatably supported by the exhaust The side swing shaft 37 is driven to have the aforementioned exhaust cam 31, the aforementioned foreign body cam 33 or the aforementioned pressure reducing device The pressure reducing cam 35 of the 34B is placed, and the exhaust valve 25 is driven to open and close.

進氣凸輪30與排氣凸輪31，是在第1與第2滾珠軸承44、45之間一體形成於凸輪軸32，而將進氣凸輪30配置於第1滾珠軸承44側，並將排氣凸輪31配置於第2滾珠軸承45側，異體凸輪33是在進氣凸輪30與排氣凸輪31之間，嵌裝於前述凸輪軸32的外周，前述減壓裝置34B是在排氣凸輪31與第2滾珠軸承45之間安裝於凸輪軸32。The intake cam 30 and the exhaust cam 31 are integrally formed on the cam shaft 32 between the first and second ball bearings 44 and 45, and the intake cam 30 is disposed on the first ball bearing 44 side, and exhausts The cam 31 is disposed on the side of the second ball bearing 45, and the foreign body cam 33 is fitted between the intake cam 30 and the exhaust cam 31 on the outer circumference of the cam shaft 32, and the decompression device 34B is in the exhaust cam 31 and The second ball bearings 45 are attached to the cam shaft 32.

前述異體凸輪33是在凸輪軸32的外周嵌裝成：可在 「接近前述排氣凸輪31且抵接於排氣側搖臂39之抵接部39b」的作動位置(第9圖中以實線表示的位置)、與「從前述排氣凸輪31分離而避免抵接於前述排氣側搖臂39之抵接部39b」的非作動位置(第9圖中以虛線表示的位置)之間，移動於前述凸輪軸32的軸線方向，並無法在該凸輪軸32的軸線周圍相對轉動。The aforementioned foreign body cam 33 is fitted on the outer circumference of the cam shaft 32 to be The operating position (the position indicated by the solid line in the ninth drawing close to the exhaust cam 31 and the abutting portion 39b of the exhaust side rocker arm 39) is separated from the "exhaust cam 31" to avoid The non-actuated position (the position indicated by the broken line in FIG. 9) abutting on the abutting portion 39b" of the exhaust side rocker arm 39 moves between the axial direction of the cam shaft 32 and cannot be in the camshaft. The axis of 32 is relatively rotated around it.

「於其中一端部同軸地具有面向螺栓58之小徑軸部59Ba」的桿59B，是可移動於軸線方向且同軸地***前述凸輪軸32的中心孔57，在桿59B與螺栓58間縮設有回動彈簧62，在桿59B的另一端連結有：於軸方向上驅動該桿59B的桿驅動手段63。The rod 59B having a small-diameter shaft portion 59Ba facing the bolt 58 coaxially at one end thereof is a central hole 57 that is movable in the axial direction and coaxially inserted into the cam shaft 32, and is contracted between the rod 59B and the bolt 58. There is a return spring 62, and a rod driving means 63 for driving the rod 59B in the axial direction is coupled to the other end of the rod 59B.

在凸輪軸32設有：連結於中心孔57的內周面與凸輪軸32的外周面之間，且在凸輪軸32的軸方向上長距離延伸的導引孔60，可移動於軸方向地安裝於凸輪軸32外周的異體凸輪33與前述桿59B，是由貫穿前述導引孔60的單一連結銷61所連結。The cam shaft 32 is provided with a guide hole 60 that is coupled between the inner circumferential surface of the center hole 57 and the outer circumferential surface of the cam shaft 32, and extends in the axial direction of the cam shaft 32, and is movable in the axial direction. The foreign body cam 33 attached to the outer circumference of the cam shaft 32 and the rod 59B are coupled by a single coupling pin 61 that penetrates the guide hole 60.

而當前述桿驅動手段63作動成「其轉動撥桿67克服回動彈簧62的彈簧力而朝第9圖的順時針方向轉動」時，異體凸輪33是從排氣凸輪31分離而形成非作動位置，此外當轉動撥桿67作動成「藉由回動彈簧62的彈簧力而朝第9圖的逆時針方向轉動」時，異體凸輪33是接近排氣凸輪31而移動至抵接於排氣側搖臂39之抵接部39b的作動位置。When the lever driving means 63 is actuated "the turning lever 67 is rotated in the clockwise direction of FIG. 9 against the spring force of the return spring 62", the foreign body cam 33 is separated from the exhaust cam 31 to form a non-actuating motion. In addition, when the turning lever 67 is actuated to "rotate in the counterclockwise direction of FIG. 9 by the spring force of the return spring 62", the foreign body cam 33 moves closer to the exhaust cam 31 to abut against the exhaust gas. The operating position of the abutting portion 39b of the side rocker arm 39.

減壓裝置34B具備：減壓配重72，該減壓配重72是 透過具有與凸輪軸32平行之軸線的減壓銷71B，而可轉動地支承於進氣凸輪30與排氣凸輪31；及減壓凸輪35，該減壓凸輪35是連結於減重配重72，而可藉由隨著「在引擎旋轉數低的狀態下，從排氣凸輪31的基圓部31a突出，並抵接於排氣側搖臂39之抵接部39a的凸輪軸32的旋轉」所產生之離心力的作用，當減壓配重72轉動時不會抵接於前述排氣側搖臂39的抵接部39a；減壓裝置34B被配置於排氣凸輪31與第2滾珠軸承45之間，並由進氣凸輪30與排氣凸輪31所支承。The decompression device 34B includes a decompression weight 72, which is a decompression weight 72 The intake cam 30 and the exhaust cam 31 are rotatably supported by a decompression pin 71B having an axis parallel to the cam shaft 32; and a decompression cam 35 coupled to the weight reduction weight 72 The rotation of the cam shaft 32 that protrudes from the base circular portion 31a of the exhaust cam 31 and abuts against the abutting portion 39a of the exhaust side rocker arm 39 can be caused by the "lower engine rotation number". The centrifugal force generated does not abut against the abutting portion 39a of the exhaust side rocker arm 39 when the decompression weight 72 rotates; the decompression device 34B is disposed between the exhaust cam 31 and the second ball bearing Between 45 and supported by the intake cam 30 and the exhaust cam 31.

減壓配重72是形成圓弧狀，而從側方覆蓋凸輪軸32的略半周，並且被配置於階梯部32a與前述排氣凸輪31之間，而使局部滑接於「面向第2滾珠軸承45的相反側，並形成於前述凸輪軸32」的該階梯部32a，且在該減壓配重72的其中一端、與位於前述凸輪軸32之排氣凸輪31的高位部31b之間，夾設有圓筒狀的支承突座75。The decompression weight 72 is formed in an arc shape and covers a slight half of the cam shaft 32 from the side, and is disposed between the step portion 32a and the exhaust cam 31 to partially slide the "facing to the second ball". The opposite side of the bearing 45 is formed in the step portion 32a of the cam shaft 32", and between one end of the decompression weight 72 and the upper portion 31b of the exhaust cam 31 located in the cam shaft 32, A cylindrical support protrusion 75 is interposed.

前述減壓銷71B，是從進氣凸輪30側貫穿該進氣凸輪30、前述排氣凸輪31、前述支承突座75及前述減壓配重72的構件，減壓銷71B的軸方向移動，是由前述凸輪軸32的階梯部32a、及「內周部被挾持於第1滾珠軸承44的內輪44a與凸輪軸32間」之墊圈79的外周部所阻止。The decompression pin 71B is a member that penetrates the intake cam 30, the exhaust cam 31, the support protrusion 75, and the decompression weight 72 from the intake cam 30 side, and the decompression pin 71B moves in the axial direction. It is blocked by the outer peripheral portion of the washer 79 of the cam shaft 32 and the outer peripheral portion of the washer 79 in which the inner peripheral portion is held between the inner ring 44a of the first ball bearing 44 and the cam shaft 32.

此外，圍繞著前述支承突座75的線圈狀扭力彈簧80，是被設於減壓配重72與凸輪軸32間，減壓配重72是將該減壓配重72的中間部，彈推至接近凸輪軸32外周面 的那一側。Further, the coil-shaped torsion spring 80 surrounding the support protrusion 75 is provided between the decompression weight 72 and the cam shaft 32, and the decompression weight 72 is the intermediate portion of the decompression weight 72. To the outer circumference of the camshaft 32 That side.

前述減壓凸輪35，是由「具有平行於凸輪軸32之軸線的軸線，且被植設於排氣凸輪31」的減壓凸輪軸84支承成可轉動，減壓凸輪35是被凸輪軸32所支承，而可以在平行於凸輪軸32之軸線的軸線周圍轉動。The decompression cam 35 is rotatably supported by a decompression camshaft 84 having an axis parallel to the axis of the camshaft 32 and being implanted in the exhaust cam 31. The decompression cam 35 is a camshaft 32. Supported, it is rotatable about an axis parallel to the axis of the camshaft 32.

該減壓裝置34B，與前述實施形態相同，在凸輪軸32的旋轉數較大的減壓停止狀態下，減壓凸輪35不會抵接於排氣側搖臂39的抵接部39a，排氣側搖臂39是追隨著排氣凸輪31的凸輪輪廓而搖動，排氣汽門25也在追隨於排氣凸輪31之凸輪輪廓的時間點開閉作動。此外，在凸輪軸32的旋轉數較小的減壓啟動狀態下，由於排氣側搖臂39的抵接部39a抵接於減壓凸輪35的圓弧部86，因此排氣側搖臂39是在「滾子54接觸於排氣凸輪31之基圓部31a」的時間點，藉由前述減壓凸輪35而形成些微的搖動，排氣汽門25也形成：無關於排氣凸輪31的凸輪輪廓，而在關閉汽門的時間點開啟汽門。In the decompression stop state in which the number of rotations of the cam shaft 32 is large, the decompression cam 35 does not abut against the abutment portion 39a of the exhaust side rocker arm 39, and the row of the decompression device 34B is arranged in the same manner as in the above-described embodiment. The gas side rocker arm 39 is swayed following the cam profile of the exhaust cam 31, and the exhaust valve 25 is also opened and closed at a time point following the cam profile of the exhaust cam 31. Further, in the decompression start state in which the number of rotations of the cam shaft 32 is small, since the abutting portion 39a of the exhaust side rocker arm 39 abuts against the arc portion 86 of the decompression cam 35, the exhaust side rocker arm 39 At the time when the "roller 54 is in contact with the base circle portion 31a of the exhaust cam 31", a slight shaking is formed by the decompression cam 35, and the exhaust valve 25 is also formed: regardless of the exhaust cam 31 The cam profile opens the valve at the point in time when the valve is closed.

根據該參考實施形態，由於作為排放氣體再循環用凸輪的異體凸輪33，被配置在排氣凸輪31與進氣凸輪30之間，因此能有效地利用排氣凸輪31與進氣凸輪30間的空間來配置異體凸輪33，且能藉由異體凸輪33的配置而避免凸輪軸32之軸長度的增加。According to this reference embodiment, since the foreign body cam 33 as the exhaust gas recirculation cam is disposed between the exhaust cam 31 and the intake cam 30, the between the exhaust cam 31 and the intake cam 30 can be effectively utilized. The foreign body cam 33 is disposed in a space, and the increase in the axial length of the cam shaft 32 can be avoided by the configuration of the foreign body cam 33.

以上雖然是針對本發明的實施形態與參考實施形態所作的說明，但本發明並不侷限於上述實施形態，只要不逸脫申請專利範圍所記載之本發明的範圍，是能有各種設計 變更的可能。The above is a description of the embodiments of the present invention and the reference embodiment, but the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the scope of the invention described in the claims. The possibility of change.

13‧‧‧汽缸頭13‧‧‧Cylinder head

17‧‧‧燃燒室17‧‧‧ combustion chamber

24‧‧‧進氣汽門24‧‧‧Intake valve

25‧‧‧作為引擎汽門的排氣汽門25‧‧‧Exhaust valve as engine valve

29A‧‧‧可變驅動汽門裝置29A‧‧‧Variable drive valve unit

30‧‧‧進氣凸輪30‧‧‧Intake cam

31‧‧‧排氣凸輪31‧‧‧Exhaust cam

32‧‧‧凸輪軸32‧‧‧Camshaft

33‧‧‧異體凸輪33‧‧‧All-in-one cam

39‧‧‧作為汽門驅動構件的排氣側搖臂39‧‧‧Exhaust side rocker arm as valve drive member

44‧‧‧作為第1軸承的第1滾珠軸承44‧‧‧1st ball bearing as the first bearing

45‧‧‧作為第2軸承的第2滾珠軸承45‧‧‧Second ball bearing as the second bearing

57‧‧‧中心孔57‧‧‧ center hole

59‧‧‧桿59‧‧‧ rod

60‧‧‧導引孔60‧‧‧ Guide hole

61‧‧‧連結銷61‧‧‧Links

63‧‧‧桿驅動手段63‧‧‧ rod driving means

64‧‧‧電磁閥64‧‧‧Solenoid valve

65‧‧‧輸出軸65‧‧‧ Output shaft

66‧‧‧支軸66‧‧‧ fulcrum

67‧‧‧轉動撥桿67‧‧‧Rotating lever

第1圖：是顯示本發明的實施形態，為引擎之重要部分的縱剖面圖。Fig. 1 is a longitudinal sectional view showing an important part of an engine according to an embodiment of the present invention.

第2圖：為第1圖中2-2線的剖面圖。Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1.

第3圖：為第2圖中箭號3所指部份的放大圖。Fig. 3 is an enlarged view of the portion indicated by arrow 3 in Fig. 2.

第4圖：為減壓停止狀態下之第3圖的4-4線剖面圖。Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3 in a state in which the pressure reduction is stopped.

第5圖：是顯示進氣汽門與排氣汽門之開啟汽門揚程特性的圖。Fig. 5 is a diagram showing the opening stroke characteristics of the intake and exhaust valves.

第6圖：為減壓停止狀態下之第3圖的6-6線放大剖面圖。Fig. 6 is an enlarged cross-sectional view taken along line 6-6 of Fig. 3 in a state in which the pressure reduction is stopped.

第7圖：為減壓裝置的分解立體圖。Fig. 7 is an exploded perspective view of the pressure reducing device.

第8圖：是對應於減壓啟動狀態下之第6圖的剖面圖。Fig. 8 is a cross-sectional view corresponding to Fig. 6 in a state in which the decompression is activated.

第9圖：是顯示參考實施形態，為對應於第3圖的剖面圖。Fig. 9 is a cross-sectional view corresponding to Fig. 3 showing a reference embodiment.

C‧‧‧中心孔57的軸線C‧‧‧Axis of the central hole 57

13‧‧‧汽缸頭13‧‧‧Cylinder head

28‧‧‧汽門驅動室28‧‧‧Vehicle Drive Room

29A‧‧‧可變驅動汽門裝置29A‧‧‧Variable drive valve unit

30‧‧‧進氣凸輪30‧‧‧Intake cam

31‧‧‧排氣凸輪31‧‧‧Exhaust cam

32‧‧‧凸輪軸32‧‧‧Camshaft

33‧‧‧異體凸輪33‧‧‧All-in-one cam

33a‧‧‧基圓部33a‧‧‧基部

33b‧‧‧高位部33b‧‧‧High Department

34A‧‧‧減壓裝置34A‧‧‧Reducing device

35‧‧‧減壓凸輪35‧‧‧Decompression cam

36‧‧‧進氣側擺動軸36‧‧‧Intake side swing axis

37‧‧‧排氣側擺動軸37‧‧‧Exhaust side swing axis

38‧‧‧進氣側搖臂38‧‧‧Intake side rocker

39‧‧‧作為汽門驅動構件的排氣側搖臂39‧‧‧Exhaust side rocker arm as valve drive member

39a‧‧‧異體凸輪的抵接部39a‧‧‧Abutment of the body cam

39b‧‧‧減壓凸輪的抵接部39b‧‧‧Relief part of the decompression cam

40‧‧‧第1軸承孔40‧‧‧1st bearing hole

41‧‧‧第2軸承孔41‧‧‧2nd bearing hole

42‧‧‧第1支承部42‧‧‧1st support

43‧‧‧第2支承部43‧‧‧2nd support

44‧‧‧作為第1軸承的第1滾珠軸承44‧‧‧1st ball bearing as the first bearing

44a‧‧‧內輪44a‧‧‧ Inner wheel

45‧‧‧作為第2軸承的第2滾珠軸承45‧‧‧Second ball bearing as the second bearing

47‧‧‧定時傳動機構(timing transmission mechanism)47‧‧‧ Timing transmission mechanism

48‧‧‧從動鏈輪48‧‧‧ driven sprocket

52‧‧‧滾子52‧‧‧Roller

54‧‧‧滾子54‧‧‧Roller

57‧‧‧中心孔57‧‧‧ center hole

58‧‧‧螺栓58‧‧‧ bolt

59A‧‧‧桿59A‧‧‧ rod

59Aa‧‧‧小徑軸部59Aa‧‧‧ Small diameter shaft

60‧‧‧導引孔60‧‧‧ Guide hole

61‧‧‧連結銷61‧‧‧Links

62‧‧‧回動彈簧(return spring)62‧‧‧Return spring

63‧‧‧桿驅動手段63‧‧‧ rod driving means

67‧‧‧轉動撥桿67‧‧‧Rotating lever

71A‧‧‧減壓銷71A‧‧‧Demolition pin

72‧‧‧減壓配重72‧‧‧Decompression weight

74‧‧‧收容凹部74‧‧‧ containment recess

75‧‧‧支承突座75‧‧‧Support stand

75a‧‧‧鍔部75a‧‧‧锷

76‧‧‧第1貫穿孔76‧‧‧1st through hole

77‧‧‧第2貫穿孔77‧‧‧2nd through hole

78‧‧‧盲孔78‧‧‧Blind hole

80‧‧‧扭力彈簧80‧‧‧Torque spring

82‧‧‧卡合孔82‧‧‧Snap hole

84‧‧‧減壓凸輪軸84‧‧‧Decompression camshaft

87‧‧‧連結銷87‧‧‧Links

88‧‧‧導引溝88‧‧‧ Guide groove

Claims (1)

一種引擎的可變驅動汽門裝置，是下述之引擎的可變驅動汽門裝置：在透過第1軸承(44)與第2軸承(45)而可自由旋轉地被引擎本體(11)的汽缸頭(13)所支承的前述凸輪軸(32)之第1與第2軸承(44、45)間，用來驅動進氣汽門(24)開閉的進氣凸輪(30)、及用來驅動排氣汽門(25)開閉的排氣凸輪(31)，是將進氣凸輪(30)配置於第1軸承(44)側而設成一體，凸輪輪廓不同於排氣凸輪(31)，且用來驅動排氣汽門(25)而使從燃燒室(17)所排出之排放氣體的一部分，回到前述燃燒室(17)的排放氣體再循環用凸輪(33)，是在排氣凸輪(31)與第2軸承(45)之間安裝於凸輪軸(32)，並且，可切換下述狀態：使連動、連結於排氣汽門(25)的汽門驅動構件(39)從動於排氣凸輪(31)的狀態；及使汽門驅動構件(39)，從動於可與凸輪軸(32)一起旋轉的排放氣體再循環用凸輪(33)的狀態，其特徵為：在前述凸輪軸(32)設有：中心孔(57)，該中心孔(57)是與該凸輪軸(32)同軸地延伸；及導引孔(60)，該導引孔(60)連結於該中心孔(57)的內周面與前述凸輪軸(32)的外周面間，且在前述凸輪軸(32)的軸方向上長距離地延伸， 可在軸方向上移動且同軸地***前述中心孔(57)內的桿(59)；及可移動於軸方向上且安裝於前述凸輪軸(32)外周的前述排放氣體再循環用凸輪(33)，是由貫穿前述導引孔(60)的連結銷(61)所連結，可在非作動位置、與作動位置之間，於軸方向上驅動前述桿(59)的桿驅動手段(63)是連結於前述桿(59)，而上述的非作動位置為：為了使前述汽門驅動構件(39)從動於前述排氣凸輪(31)，使前述排放氣體再循環用凸輪(33)從前述排氣凸輪(31)隔離的位置；而上述的作動位置為：為了使前述汽門驅動構件(39)從動於前述排放氣體再循環用凸輪(33)，使前述排放氣體再循環用凸輪(33)接近前述排氣凸輪(31)的位置，該桿驅動手段(63)具備：電磁閥(64)，該電磁閥(64)具有與前述凸輪軸(32)平行的輸出軸(65)，且被安裝於前述引擎本體(11)；及轉動撥桿(67)，該轉動撥桿(67)透過支軸(66)而可自由轉動地由前述引擎本體(11)所支承；並且在從前述支軸(66)分離的2個位置，前述輸出軸(65)及前述桿(59)分別抵接於該轉動撥桿(67)，使前述桿(59)透過轉動撥桿(67)而連動、連結於該輸出軸(65)。 A variable drive valve device for an engine is a variable drive valve device of an engine that is rotatably driven by an engine body (11) through a first bearing (44) and a second bearing (45) An intake cam (30) for driving the intake and exhaust valve (24) to open and close between the first and second bearings (44, 45) of the cam shaft (32) supported by the cylinder head (13), and The exhaust cam (31) that drives the exhaust valve (25) to open and close is integrally disposed with the intake cam (30) disposed on the first bearing (44) side, and the cam profile is different from the exhaust cam (31). And the exhaust gas recirculation cam (33) for driving the exhaust valve (25) to return a part of the exhaust gas discharged from the combustion chamber (17) to the combustion chamber (17) A cam shaft (32) is attached between the cam (31) and the second bearing (45), and a state in which the valve driving member (39) linked to the exhaust valve (25) is interlocked is switched from a state in which the exhaust cam (31) is moved; and a state in which the valve driving member (39) is driven by the exhaust gas recirculation cam (33) rotatable together with the cam shaft (32), and is characterized by: The aforementioned camshaft (32) is provided with: a core hole (57) extending coaxially with the cam shaft (32); and a guiding hole (60) coupled to the inner circumference of the center hole (57) a surface extending between the outer peripheral surface of the cam shaft (32) and a long distance in the axial direction of the cam shaft (32), a rod (59) movable in the axial direction and coaxially inserted into the center hole (57); and the aforementioned exhaust gas recirculation cam (33) movable in the axial direction and mounted on the outer circumference of the cam shaft (32) The rod driving means (63) for driving the rod (59) in the axial direction between the non-actuated position and the actuating position is connected by a connecting pin (61) penetrating through the guiding hole (60). Is coupled to the rod (59), and the non-actuating position is such that the exhaust gas recirculation cam (33) is driven in order to cause the valve driving member (39) to be driven by the exhaust cam (31). a position at which the exhaust cam (31) is isolated; and the actuating position is such that the exhaust gas recirculating cam is driven in order to cause the valve driving member (39) to be driven by the exhaust gas recirculating cam (33) (33) approaching the position of the exhaust cam (31), the lever driving means (63) is provided with a solenoid valve (64) having an output shaft (65) parallel to the cam shaft (32) And being mounted on the engine body (11); and a rotary lever (67), the rotary lever (67) is freely rotatable through the support shaft (66) The ground body is supported by the engine body (11); and at two positions separated from the support shaft (66), the output shaft (65) and the rod (59) abut against the rotary lever (67), respectively. The rod (59) is interlocked and coupled to the output shaft (65) through the rotary lever (67).
TW098126742A 2008-09-30 2009-08-10 Engine variable drive valve assembly TWI384119B (en)

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JP2010084625A (en) 2010-04-15
TW201013034A (en) 2010-04-01

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