Lubricating system for valve operating system

A lubricating system for a valve operating system includes a valve operating system configured to reciprocate a valve for substantially opening and closing a port connected to a combustion chamber of an engine, and an ejecting device provided with an outlet from which a lubricating liquid is ejected. The valve operating system includes a drive cam, a driven member configured to contact the drive cam, a pivot member which is attached to the driven member and is configured to transmit movement of the driven member to the valve, and a relative position changing device configured to change relative positions of the driven member and the pivot member. The outlet of the ejecting device is oriented to face sliding surfaces of the driven member and the drive cam at least in a period which is a part of one rotation of the drive cam.

TECHNICAL FIELD

The present invention relates to a lubricating system for a valve operating system configured to reciprocate a valve which substantially opens and closes a port connected to a combustion chamber of an engine.

BACKGROUND ART

A variable valve timing control system in an engine is configured to change a rotational movement of a drive cam which is rotatable in association with a rotation of a crankshaft to a reciprocating movement of a valve by a pivot cam device. The variable valve timing control system is configured to change a pivot angle range of the pivot cam device to enable valve timing control according to an engine speed (see Japanese Laid-Open Patent Application Publication No. 2005-180232).

However, in such a variable valve timing control system, since a valve must be applied with a force from a spring to perform the reciprocating movement, a pressing force applied by a drive cam to another component positioned between the drive cam and the valve is large, and a sliding friction force generated on slide surfaces of the drive cam and another component, which are slidable relative to each other, is large. For this reason, the sliding surfaces tend to wear out and are low in durability.

SUMMARY OF THE INVENTION

The present invention addresses the above described condition, and an object of the present invention is to provide a valve operating system in an engine which is capable of improving durability of sliding surfaces of a pivot cam device and a drive cam.

According to the present invention, a lubricating system for a valve operating system comprises a valve operating system configured to reciprocate a valve for substantially opening and closing a port connected to a combustion chamber of an engine; and an ejecting device in which a lubricating liquid for lubricating the valve operating system flows, the ejecting device being provided with an outlet from which the lubricating liquid is ejected, wherein the valve operating system includes a drive cam configured to operate in association with rotation of a crankshaft of the engine; a driven member configured to contact the drive cam; a pivot member which is attached to the driven member and is configured to transmit movement of the driven member to the valve; and a relative position changing device configured to change relative positions of the driven member and the pivot member; wherein the outlet of the ejecting device is oriented to face sliding surfaces of the driven member and the drive cam at least in a period which is a part of one rotation of the drive cam.

In such a configuration, during the operation of the valve operating system in which the relative positions of the driven member and the pivot member are changeable, the lubricating liquid ejected from the outlet of the ejecting device is directly applied to the sliding surfaces of the driven member and the drive cam. As a result, the lubricating liquid is sufficiently fed to the sliding surfaces of the driven member and the drive cam so that an oil film thickness on the sliding surfaces is stably maintained. This enables improvement of durability against wear out of the valve operating system. It should be noted that the sliding surfaces are contact surfaces of the driven member and the drive cam which are slidable relative to each other, and it suffices that the lubricating liquid ejected from the outlet of the ejecting device is applied to at least one of the sliding surfaces of the driven member and the drive cam.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a right side view of a motorcycle1equipped with an engine E according to an embodiment of the present invention. Herein, directions are generally referenced from the perspective of a rider R mounting the motorcycle1.

Turning now toFIG. 1, the motorcycle1includes a front wheel2and a rear wheel3. The front wheel2is rotatably mounted to a lower portion of a front fork5extending substantially vertically. The front fork5is mounted on a steering shaft (not shown) by an upper bracket (not shown) attached to an upper end thereof, and an under bracket located below the upper bracket. The steering shaft is rotatably supported by a head pipe6. A bar-type steering handle4extending in a rightward and leftward direction is attached to the upper bracket. When the rider R rotates the steering handle4clockwise or counterclockwise, the front wheel2is turned to a desired direction around the steering shaft.

A pair of right and left main frame members7, forming a frame of a vehicle body of the motorcycle1, extend rearward from the head pipe6. Pivot frame members8extend downward from rear portions of the main frame members7, respectively. A swing arm10is pivotally mounted at a front end portion thereof to a pivot9provided at each of the pivot frame members8. The rear wheel3is rotatably mounted at a rear end portion of the swing arm10.

A fuel tank12is disposed above the main frame members7and behind the steering handle4. A straddle-type seat13is disposed behind the fuel tank12. An engine E is mounted between and below the right and left main frame members7. A driving power of the engine E is transmitted to the rear wheel3via a chain (not shown), causing the rear wheel3to rotate. Thereby, the driving power is applied to the motorcycle1. A cowling19, which is an integral member, is provided to cover a front portion of the motorcycle1, i.e., the head pipe6, a front portion of the main frame members7, and side portions of the engine E. Straddling the seat13, the rider R mounts the motorcycle1. Gripping a grip4aprovided at an end portion of the steering handle4and putting the rider R's feet on steps14provided in the vicinity of a rear portion of the engine E, the rider R drives the motorcycle1.

FIG. 2is a right side view of the engine ofFIG. 1, which is enlarged and partly in cross-section. As shown inFIG. 2, the engine E includes a cylinder head20, a cylinder head cover21, a cylinder block22, and a crankcase23. The engine E is an in-line four-cylinder double overhead camshaft (DOHC) engine. In a rear portion of the cylinder head20, an intake port20A is provided to open rearward and upward so as to correspond to each cylinder, while in a front portion of the cylinder head20, an exhaust port20B opens forward. In an upper portion of the cylinder head20of the engine E, a drive camshaft24for driving an intake valve and a drive camshaft25for driving an exhaust valve are disposed. The drive camshafts24and25are rotatably retained by a shaft support body49(seeFIG. 3). The cylinder head cover21covers a shaft support body49from above, and is fastened to the cylinder head20.

The cylinder block22is coupled to a lower portion of the cylinder head20and is configured to accommodate a piston (not shown) therein. The crankcase23is coupled to a lower portion of the cylinder block22and is configured to accommodate the crankshaft26extending in a width direction of the vehicle body of the motorcycle1. In a right wall portion of the cylinder head20, a right wall portion of the cylinder block22, and a right wall portion of the crankcase23, a chain tunnel27is formed to accommodate a rotation transmission system28configured to transmit a rotational driving force of the crankshaft26to the drive camshafts24and25. An oil pan29is provided at a lower portion of the crankcase23and is configured to reserve oil (lubricating liquid) for lubricating or hydraulically powering engine components. An oil filter30is provided at a front portion of the crankcase23and serves to filter the oil suctioned from the oil pan29.

The rotation transmission system28includes an intake cam sprocket31, an exhaust cam sprocket32, a crank sprocket33, and a timing chain34. To be specific, a right end portion of the drive camshaft24protrudes into the chain tunnel27, and the intake cam sprocket31is provided at the right end portion of the drive camshaft24. A right end portion of the drive camshaft25protrudes into the chain tunnel27, and the exhaust cam sprocket32is provided at the right end portion of the drive camshaft25. A right end portion of the crankshaft26protrudes into the chain tunnel27, and the crank sprocket33is provided at the right end portion of the crankshaft26.

The timing chain34is installed around the intake cam sprocket31, the exhaust cam sprocket32, and the crank sprocket33. When the crank sprocket33rotates, the intake cam sprocket31and the exhaust cam sprocket33rotate in association with the rotation of the crank sprocket33. Thus, the rotation transmission system28including the intake cam sprocket31, the exhaust cam sprocket32, the crank sprocket33and the timing chain34enables the rotational driving force of the crankshaft26to be transmitted to the drive camshafts24and25. Therefore, the drive camshafts24and25rotate in synchronization with the crankshaft26in a cycle which is ½ of a rotational cycle of the crankshaft26.

A movable chain guide35and a fixed chain guide36are provided in the interior of the chain tunnel27. The fixed chain guide36extends vertically in front of the timing chain34. The fixed chain guide36extends from a position in front of and in the vicinity of the crank sprocket33to a position below and in the vicinity of the exhaust cam sprocket32. The fixed chain guide36is provided with a groove (not shown) formed in a rear portion thereof to extend along the longitudinal direction thereof. The groove enables the timing chain34to be supported from forward.

The movable chain guide35extends vertically behind the timing chain34. The movable chain guide35is pivotally mounted at a lower end portion thereof to the right wall portion of the crankcase23at a position above and in the vicinity of the crank sprocket33. An upper end portion of the movable chain guide35is positioned below and in the vicinity of the intake cam sprocket31. A hydraulically-powered tensioner37is provided on a rear wall portion of the cylinder head20. The movable chain guide35is subjected to at an upper portion thereof a forward force from the hydraulic tensioner37. The movable chain guide35serves to support the timing chain34from behind and apply a suitable tension to the timing chain34.

An output gear38is mounted on a right side portion of the crankshaft26. The output gear38is rotatable integrally with the crankshaft26to output the rotation of the crankshaft26. A transmission chamber39is formed in a rear portion of the crankcase23. The transmission chamber39accommodates therein an input shaft40and an output shaft (not shown) extending substantially in parallel with the crankshaft26. A plurality of gears41are mounted on the input shaft40and the output shaft and constitute a transmission42. An input gear43is mounted on a right end portion of the input shaft40. The input gear43is configured to mesh with the output gear38of the crankshaft26and is rotatable integrally with the input shaft40. In this structure, an engine driving power of the engine E is transmitted from the crankshaft26to the input shaft40via the output gear38and the input gear43. Then, the transmission42changes the rotational speed of the engine driving power and outputs the resulting driving power to the rear wheel3(FIG. 1).

The engine E includes a trochoidal rotor type oil pump44. The oil pump44includes a pump driven gear46which is configured to mesh with a pump drive gear45mounted on the input shaft40of the transmission42. The oil pump44is driven in association with the rotation of the crankshaft26. The engine E is provided with lubricating or hydraulic oil passages to feed to the engine components the oil47suctioned up from the oil pan29by the oil pump44.

FIG. 3is an enlarged cross-sectional view of intake and exhaust valve operating systems50A and50B and others in the engine E ofFIG. 1. As shown inFIG. 3, the cylinder head20is provided with an intake valve device51A configured to open and close a combustion chamber52with respect to the intake port20A, and an exhaust valve device51B configured to open and close the combustion chamber52with respect to the exhaust port20B. Four combustion chambers52are arranged in one line in a depth direction ofFIG. 3. The intake valve operating system50A causes the intake valve device51A to open and close (reciprocate), while the exhaust valve operating system50B causes the exhaust valve device51B to open and close (reciprocate). Since the intake valve device51A and the exhaust valve device51B have substantially the same structure and the intake valve operating system50A and the exhaust valve operating system50B have substantially the same structure, the intake valve device51A and the intake valve operating system50A will be described.

The intake valve device51A has a known structure, and includes a valve body53having a flange portion53aconfigured to open and close the intake port20A, and a stem portion53bextending upward from the flange portion53a.The stem portion53bis provided with a groove at an upper end portion thereof. A cotter56is inserted into the groove of the stem portion53b.A spring retainer55is mounted to the cotter56. A spring seat54is mounted to an upper surface of the cylinder head20. A valve spring57is mounted between the spring seat54and the spring retainer55. The valve spring57applies an upward force to the valve body53, and closes the intake port20A. A tappet58is attached to an upper surface of the cotter56.

The intake valve operating system50A includes the drive camshaft24configured to operate in association with the rotation of the crankshaft26of the engine E, a drive cam24afixed to the drive camshaft24, and a pivot cam device48configured to contact the drive cam24ato transmit the movement of the drive cam24ato the tappet58of the intake valve device51A.

FIG. 4is a perspective view showing major components of the pivot cam device48ofFIG. 3.FIG. 5is a perspective view showing major components of the pivot cam device48ofFIG. 4, as viewed from another angle. As shown inFIGS. 3 to 5, the pivot cam device48includes a driven member64configured to contact the drive cam24a,a pivot member61which is mounted to the driven member64and is configured to press the tappet58of the intake valve device51A, and a relative position changing device80configured to change relative positions of the driven member64and the pivot member61. The relative position changing device80includes a control shaft60configured to pivotally support the pivot member61, a coupling pin65coupling the driven member64to the pivot member61such that the driven member64is angularly displaceable with respect to the pivot member61, a roller62(operation member) which is rotatably provided at a part of the control shaft60and is configured to support the driven member64against a force from the drive cam24a,and a spring70configured to apply a force to cause the driven member64to move toward the drive cam24a.

The pivot member61has a ring-shaped portion61awhich is rotatably and externally fitted to the control shaft60and a claw-shaped pivot portion61bprotruding toward the exhaust valve device51B at a lower portion of the ring-shaped portion61a.The pivot portion61bhas a substantially sector shape to form a pivot portion sliding surface of a substantially circular-arc shape and protrudes radially outward from the ring-shaped portion61a.The pivot portion sliding surface extends along a flat plane perpendicular to an axis of the ring-shaped portion61a.A distance between the pivot portion sliding surface and the center of the ring-shaped portion61achanges in the direction from one end portion of the sliding surface to an opposite end portion of the sliding surface. A cut portion61eis formed on an upper portion of the ring-shaped portion61aso as to extend in a circumferential direction of ring-shaped portion61a.A pair of pin support portions61cand61dare provided at both sides of the cut portion61ein the ring-shaped portion61ato be oriented upward and substantially toward the exhaust valve device51B. A through hole61finto which the coupling pin65is inserted is formed in the pin support portions61cand61d.Therefore, the pin support portions61cand61dare integrally fastened to the ring-shaped portion61a,and the through hole61fof the pin support portions61cand61dis positioned closer to the center of a virtual circle including the pivot portion sliding surface. The pin support portions61cand61dsupport the driven member64such that the driven member64is angularly displaceable around the axis of the through hole61fby the coupling pin65. The axis of the roller62is positioned eccentrically from the axis of the control shaft60. The axis of the roller62partially protrudes radially outward from the control shaft60. The roller62is loosely fitted in the cut portion60aof the pivot member61so that the control shaft60is angularly displaceable around the center of the driven member64.

The driven member64has a ring-shaped support portion64ainto which the coupling pin65is inserted and a claw-shaped driven portion64bprotruding upward and substantially toward the exhaust valve device51B at the support portion64a.The driven portion64bhas a substantially sector shape to form a driven portion sliding surface of a substantially circular-arc shape, and protrudes radially outward from the support portion64a.The driven portion sliding surface extends along a flat plane perpendicular to the axis of the support portion64a.A distance between the driven portion sliding surface and the center of the support portion64achanges in the direction from one end portion of the sliding surface to an opposite end portion of the sliding surface.

A lever portion64cprotrudes downward from the support portion64and is configured to contact the roller62. The lever portion64cis disposed at an opposite side of the driven portion64bwith respect to the support portion64a.A roller contact surface of the lever portion64cand the driven portion sliding surface of the driven portion64bextend substantially along a virtual circular-arc shape. The support portion64ais disposed inside of the virtual circular-arc. The lever portion64cis loosely fitted in a space of the cut portion61eof the pivot member61. When the lever portion64ccontacts the roller62, further angular displacement of the driven member64around the pin support portions61cand61dis restricted. The coil-shaped spring70is externally fitted to the control shaft60. One end portion70aof the spring70is wound around the coupling pin65, and an opposite end portion70bthereof extends in a direction opposite to the direction in which the one end portion70aextends. The opposite end portion70bof the spring70is sandwiched and retained between a lower surface of a lower bearing concave portion67bto be described later and the upper surface of the cylinder head20.

A cut portion60ais formed on the control shaft60in a position corresponding to the driven member64. The roller62is disposed in the cut portion60a.The roller62is rotatably supported by a shaft63axially penetrating through the inside of the control shaft60. When the control shaft60rotates, the position of the roller62changes, changing a contact position of the lever portion64cof the driven member64with respect to the roller62. Thereby, the relative positions of the driven member64and the pivot member61are changed around the coupling pin65. In other words, according to the angular displacement of the control shaft60, the position around the axis of the control shaft60where the angular displacement of the driven member64is restricted is changed. On the other hand, irrespective of the angular displacement of the control shaft60, the position around the axis of the control shaft60where the pivot member61is angularly displaced, is not changed. As a result, according to the angular displacement of the control shaft60, a relative position relationship in the circumferential direction of the control shaft60between the pivot member61and the driven member64is changed.

As shown inFIG. 3, the shaft support body49is provided on the upper surface of the cylinder head20and is configured to rotatably support the drive camshaft24. The shaft support body49includes a lower support member67protruding from the upper surface of the cylinder head20, and an upper support member68mounted to the lower support member67from above by a bolt69. The lower support member67has a lower bearing concave portion67bhaving a semicircular cross-section. The upper support member68has an upper bearing concave portion68ahaving a semicircular cross-section which is opposite to the lower bearing concave portion67b.The drive camshaft24is rotatably inserted into a space which is defined by the lower bearing concave portion67band the upper bearing concave portion68band has a circular cross-section.

The lower support member67has an insertion hole67apenetrating therethrough in an axial direction of the drive camshaft24. An oil pipe (lubricating liquid pipe)66is inserted into the insertion hole67a.That is, a pair of oil pipes66are provided between the intake valve operating system50A and the exhaust valve operating system50B. A plurality of outlets66aopen on a peripheral wall of each oil pipe66such that they are spaced apart from each other in an axial direction of each oil pipe66. Through the outlets66a,the oil flowing within the oil pipe66is ejected toward the intake valve operating system50A.

The outlets66aof the oil pipe66are located closer to a tip end portion of the claw-shaped driven portion64bof the driven member64such that the outlets66aare opposite to the tip end portion of the driven portion64b.To be specific, the oil pipe66for the intake valve device51A is disposed in a center space formed between the intake valve device51A and the exhaust valve device51B. The outlets66aof the oil pipe66are oriented to face sliding surfaces which are the contact surfaces of the driven portion64bof the driven member64and the drive cam24awhich are slidable relative to each other in at least a position of a movable range of the pivot cam device48. In other words, the outlets66aof the oil pipe66are oriented to face the sliding surfaces of the driven member64and the drive cam24aat least in a period which is a part of one rotation of the drive cam24a.

To be more specific, the outlets66aare located above a lowermost position of the tip end portion of the driven portion64bwhile the drive camshafts24and25are rotating once so that the oil ejected from the outlets66ais applied to the driven portion64bfrom above. The oil pipe66is located in close proximity to the drive cam24aoutside a moving range, i.e., a movement track of the drive cam24aand the driven member64so that the oil ejected from the outlets66ais easily applied to the sliding surfaces of the driven portion64band the drive cam24a.

The oil pipe66is located between the drive camshaft24and the control shaft60in a vertical direction so that the oil is applied to both the drive cam24aand the driven portion64b.Furthermore, in a state where the drive cam24aand a base end region of the sliding surface of the driven portion64b,which is closer to the support portion64a,are in contact with each other, the oil is ejected into a space defined by the sliding surface of the drive cam24aand the sliding surface of the driven portion64b.As should be appreciated, the oil pipe66serves as a guiding member to guide the oil to the sliding surfaces.

FIG. 6is a plan view showing the engine E ofFIG. 3, from which the head cover21is removed.FIG. 7is a plan view showing the engine E ofFIG. 6, from which the upper support member68and the drive camshafts24and25are further removed. Turning toFIG. 6, the intake valve operating system50A is aligned on one side relative to four combustion chambers52arranged in one line, while the exhaust valve operating system50B is aligned on the other side relative to the four combustion chambers52. That is, the intake valve operating system50A and the exhaust valve operating system50B are positioned at opposite sides with respect to the four combustion chambers52disposed therebetween. The drive camshafts24and25respectively extend in the direction in which the intake and exhaust valve operating systems50A and50B are aligned. The drive camshafts24and25are coupled to the cam sprockets31and32in the interior of the chain tunnel27, respectively.

Turning toFIG. 7, the control shafts60respectively extend in the direction in which the intake and exhaust valve operating systems50A and50B are aligned. A gear chamber71is provided at an end portion of the engine E which is located far from the chain tunnel27. A control gear74is disposed in the gear chamber71and is configured to mesh with the control shaft60. The control gear74is driven by a motor73mounted to the engine E. That is, the motor73drives the control gear74to cause the control shaft60to rotate. The motor73is electronically controlled by an ECU (electronic control unit).

As shown inFIGS. 6 and 7, the pair of oil pipes66are arranged to extend in the center space between the intake valve operating system50A and the exhaust valve operating system50B in the direction in which the intake and exhaust valve operating systems50A and50B are aligned, i.e., along the axial direction of the drive camshafts24and25and the axial direction of the control shafts60. One end portion of each oil pipe66is coupled to a pipe coupling portion72provided at the upper surface of the cylinder head20. The pipe coupling portion72has an oil feed passage (not shown) to which the oil suctioned from the oil pan29by the oil pump44is fed, to feed the oil to the oil pipe66.

Subsequently, an operation principle of the pivot cam device48will be described.FIG. 8is a view showing a normal operation of the valve operating system50ofFIG. 3. As shown inFIG. 8, at a time point when the tip end portion of the drive cam24ais located at an upper limit position, i.e., a lift amount is zero, a force is applied to the driven member64from the spring70(seeFIG. 4) via the coupling pin65so that the driven member64is pressed against the drive cam24a.In this case, since the lever portion64cof the driven member64is in contact with the roller62, the rotation of the driven member64around the coupling pin65to cause the driven portion64bto be closer to the pivot portion61bis inhibited.

When the drive cam24arotates counterclockwise inFIG. 8, the driven member64is pressed down by the drive cam24a.During this operation, since the driven member64is coupled to the pivot member61by the coupling pin65, the pivot member61is pivoted around the control shaft60while causing the ring-shaped portion61ato slide on the outer peripheral surface of the control shaft60. Thereby, the pivot portion61aof the pivot member61presses down the tappet58, and the valve body53moves downward (lift), so that the intake port20A is opened.

The oil pipe66is disposed so that the outlets66aof the oil pipe66are oriented to face the sliding portions of the driven member64and the drive cam24ain at least one position in the movable range of the pivot cam device48configured to operate as described above. In this structure, during the operation of the intake valve operating system50A, the oil47ejected from the outlets66aof the oil pipe66is directly applied to the sliding surfaces of the driven member64and the drive cam24a.As a result, the oil47is sufficiently fed to the sliding surfaces so that an oil film thickness on the sliding surfaces is stably maintained. This enables improvement of durability against wear out, or the like of the intake valve operating system50A.

FIG. 9is a view showing the operation of the intake valve operating system50A ofFIG. 3, occurring when its angle is changed. As shown inFIG. 9, when the control shaft60rotates counterclockwise inFIG. 9, the roller62moves according to the rotation. Thereby, a contact position of the lever portion64cof the driven member64with respect to the roller62is changed, and an angle (relative position) formed between the driven member64and the pivot member61is changed. Therefore, the operation timing and lift amount of the valve body53which is pressed down via the tappet58by the pivot member61are changed. To be specific, an angle formed between the driven portion64band the pivot portion61bis small, and the valve open time and lift amount of the valve body53are small. The oil pipe66is disposed so that the outlets66aare oriented to face the sliding portions of the driven member64and the drive cam24ain at least one position in the movable range of the pivot cam device48even when the angle of the intake valve operating system50A is changed as shown inFIG. 9.

As described above, the variable valve timing operating systems (intake and exhaust valve operating systems)50A and50B are applied to the motorcycle1which is frequently driven in a high rotational range. It is desired that a sufficient amount of oil be fed to the sliding surfaces of the pivot cam device48and the drive cam24a,as well as to the coupling regions of the components constituting the intake and exhaust valve operating systems50A and50B, and the oil film thickness on these regions be stably maintained. To this end, in the motorcycle1configured as described above, the oil47ejected from the outlets66aof the oil pipe66is directly applied to the sliding surfaces of the driven member64and the drive cam24aduring the operation of the intake and exhaust valve operating systems50A and50B. Therefore, the oil47is sufficiently supplied to the sliding surfaces of the driven member64and the drive cam24aso that durability against the wear out of the sliding surfaces is improved.

Since the oil pipe66is inserted into the insertion hole67aprovided in the shaft support body49, a member for supporting the oil pipe66may be omitted. This makes it possible to reduce the number of components and achieve space saving. Further, since the oil pipe66is mounted to the lower support member67of the shaft support body49, and a coupling state of the oil pipe66is maintained even if the upper support member68is detached from the lower support member67, it is not necessary to attach and detach the oil pipe66when attaching and detaching the upper support member68. This makes it easy to carry out maintenance.

Since the pair of oil pipes66are disposed in the center space formed between the line of the intake valve operating system50A and the line of the exhaust valve operating system50B, it is not necessary to provide a space used for disposing the oil pipes66. As a result, the engine E is not increased in size. Furthermore, since the outlets66aof the oil pipe66are located closer to the tip end portion of the driven member64, which is displaceable in a maximum amount, the oil reaches the sliding surface of the driven member64in any position during the movement of the driven member64and lubricates the sliding surface stably even if the movement track of the oil ejected from the outlets66achanges to some degree.

Since the roller62with which the lever portion64cof the driven member64is configured to contact is rotatable around the shaft63, a friction operation occurring between the driven member64and the roller62is suppressed. As a result, wear-out of the driven member64and the roller62is avoided, and hence, durability of them is improved. Furthermore, since the roller62is separate from the control shaft60, an initial relative position relationship between the driven member64and the pivot member61is easily adjusted merely by changing the roller62with a roller having a different outer diameter.

Whereas in the intake and exhaust valve operating systems50A and50B of the present embodiment, the lift amount is variable, a phase angle or an operation angle may alternatively be variable. Whereas in the present embodiment, the oil pipe66having the outlets66ais used as the ejecting device, a nozzle device, an injector, and others for ejecting the oil may alternatively be used. Whereas in the present embodiment, the motorcycle1is illustrated, the present invention is applicable to other vehicles. Furthermore, the lubricating system for the valve operating system of the present invention is not intended to be limited to the above described embodiments.