JP4220949B2 - Lubricating oil passage for variable valve drive device, variable valve drive device, engine and motorcycle - Google Patents

Description

  The present invention relates to a lubricating oil passage of a variable valve driving device provided in an engine, a variable valve driving device, an engine, and a motorcycle.

  Conventionally, in a four-cycle engine, a variable valve timing mechanism that changes valve opening / closing timing according to each of high engine speed and low / medium engine speed is known. The variable valve timing mechanism changes the valve opening / closing timing to change the period (valve overlap) in which the intake valve and the exhaust valve are simultaneously opened according to the engine speed. Thereby, it is possible to achieve high engine output, low fuel consumption, and further reduction of exhaust gas without changing the displacement.

  As a general variable valve timing mechanism, for example, in a cam drive sprocket that is linked to crank drive, a cam drive shaft that is linked to the crankshaft and a cam shaft that is integrally provided with the cam are driven. The part which provided the rotation phase difference in the part is mentioned.

  This type of variable valve timing mechanism has a structure in which the valve timing is changed without changing the cam working angle (also referred to as “operation angle”), so that the valve drive structure in a conventional engine is not significantly changed. This can be realized simply by changing the portion of the cam sprocket that is linked to the crankshaft.

  As a technique for making the cam operating angle variable, a reduction ratio of the cam angle to the crank angle is provided by arranging a coupling (eccentric member) that causes an angular velocity fluctuation between the cam drive shaft portion and the cam shaft portion. It has been proposed to periodically change and control the fluctuation.

  For example, in Patent Document 1, a cam drive shaft that follows the rotational drive of a crank is inserted into a cam and a disc-shaped eccentric plate (eccentric member), and a pin provided on the cam drive shaft extends in a radial direction on the eccentric plate. Loosely fitted. When the cam drive shaft rotates, the eccentric plate rotates in a state of being eccentric with respect to the cam drive shaft via the pin and the groove to drive the cam. Patent Document 2 is known as having the same basic configuration as Patent Document 1.

  Furthermore, in Patent Document 3, an eccentric plate (eccentric member) is disposed between a sprocket that rotates by transmission of a driving force from a crankshaft via a gear train and a camshaft that is provided integrally with the cam. Power is transmitted from the sprocket to the camshaft via the eccentric plate.

  Note that these variable valve timing mechanisms are mainly applied to multi-cylinder engines of automobiles, and in a multi-cylinder engine, it is necessary to shift the periodic speed fluctuations of the cams in each cylinder in different phases. Equipped with an eccentric plate.

  In addition, a variable timing mechanism including a variable mechanism including an eccentric plate is provided with a lubrication path for supplying lubricating oil to the sliding portion in order to prevent wear and seizure of the members at the sliding portion of the constituent members.

For example, in Patent Document 4, an eccentric member is provided between a drive shaft that is rotationally driven via a cam sprocket and a cam shaft in which the drive shaft is rotatably inserted and the cam is integrally provided. In Patent Document 4, a cam is disposed between a cam sprocket and an eccentric member, and an oil passage penetrating in the axial direction is formed in a drive shaft that is rotatably inserted into the cam. Lubricating oil is supplied from the cam sprocket side to the eccentric member side through this oil passage, lubricates the variable mechanism including the eccentric member, and then is supplied to the sliding portion of the adjacent cam piece, which lubricates the sliding portion. is doing.
Japanese Examined Patent Publication No. 47-020654 Japanese Patent Laid-Open No. 5-118208 Japanese Patent Laid-Open No. 3-43611 Utility Model Registration No. 2586663

  In recent years, it has been considered that a variable valve timing mechanism is mounted on a motorcycle due to an exhaust gas regulation problem or the like. In a motorcycle, in particular, a scooter type vehicle (hereinafter referred to as “scooter”) or the like, it is desirable that the engine structure is further simplified due to limitations on vehicle dimensions.

  However, in all of the techniques of Patent Document 1 to Patent Document 3, a coupling (for example, an eccentric plate) as a variable mechanism that changes the working angle of the cam is a drive portion (cam sprocket) that rotates at the same rotation as the cam drive shaft. ) And the camshaft. For this reason, when mounted on a motorcycle, it is necessary to significantly change the structure of the conventional non-variable specification conventional engine in which the cam drive member is disposed at a position close to the cylinder shaft. In other words, when a conventional non-variable engine is changed to a variable engine, it is necessary to change main engine components such as a cylinder head and a component that transmits driving force from a crankshaft to a cam driving shaft. Arise. Therefore, there is a problem that main components cannot be used in common with non-variable engines.

  Further, in the techniques of Patent Documents 1 to 3, since the cam sprocket and the cam are arranged apart from each other as compared with the conventional engine, the chain line of the cam drive chain arranged substantially orthogonal to the crankshaft is a cylinder. And away from the line where the cam is located. As a result, the engine itself becomes larger as the cylinder and cam arrangement line and the chain line are separated from each other. When incorporated in a motorcycle engine, the engine with a variable valve timing mechanism has a chain line that is different from the conventional one. Has a problem that it protrudes outside the engine and the entire engine becomes large.

  Particularly in the scooter, structurally, a CVT (Continuously Variable Transmission) sheave and the like are provided on the crankshaft on the outer side of the vehicle center than the cam drive chain. For this reason, when a conventional variable valve timing mechanism is mounted on a scooter, a component having a width such as a sheave is a rotating body (crank pulley, Timing gear, etc.).

  As a result, the engine itself has a structure that protrudes in the crankshaft direction as a whole, as compared with a structure in which the variable valve timing mechanism is not mounted. Therefore, in a motorcycle equipped with an engine with the crankshaft facing in the width direction, for example, a scooter having a swing arm, the width of the crankcase becomes large, a sufficient bank angle cannot be obtained, and the motion characteristics of the vehicle deteriorate. There is a problem of doing.

  Therefore, in recent years, there has been a demand for a variable valve driving device that is not mounted on a scooter or the like and that does not significantly change the engine configuration and does not deteriorate the motion performance of the scooter.

  In addition, in such a variable valve drive device, a lubricating oil passage for efficiently lubricating the sliding portion between the constituent members of the device is essential. As an example of the configuration of the lubricating oil path in the variable valve drive device, it is conceivable to apply the configuration of Patent Document 4.

  However, in this patent document 4, the lubrication oil is supplied to the sliding portion of the cam piece after the sliding portion of the variable mechanism is lubricated. For this reason, particularly when the engine is started, there is a problem that the lubrication oil supply is delayed and the lubrication oil supply efficiency is deteriorated by the amount of lubrication to the cam piece after the lubrication of the variable mechanism portion.

  The present invention has been made in view of the above points, and in a variable valve driving device that can be mounted without significantly changing the engine configuration and can change the operating angle of the cam, the variable can efficiently lubricate the sliding portion of the member. It is an object of the present invention to provide a lubricating oil passage for a valve driving device, a variable valve driving device, an engine, and a motorcycle.

  The lubricating oil passage of the variable valve driving device of the present invention is disposed adjacent to a cam driving member that is rotationally driven by a driving force transmitted from a crankshaft, and one end of the rotating shaft of the cam driving member, and the cam driving member An eccentric member that rotates about an axis in the same direction as the rotation axis of the cam drive member and is movable to an eccentric position from an axial center position of the rotation shaft, and the rotation shaft; It is arranged on the same axis and is rotationally driven around the rotational axis by the eccentric member, and the rotational phase difference with respect to the cam drive member periodically varies when the eccentric member is rotationally driven at the eccentric position. A cam shaft and a cam piece that is disposed on the other end side of the rotation shaft of the cam drive member, is driven to rotate at the same rotation phase as the cam shaft by the cam shaft, and drives an exhaust or intake valve. A lubricating oil passage of the valve driving device, provided through the rotation shaft of the cam driving member, supplying lubricating oil to a sliding portion of the cam piece on the other end side of the cam driving member; A configuration is adopted in which a lubricating path for supplying lubricating oil to a sliding portion of the eccentric member on one end side of the cam driving member is provided.

  According to this configuration, the eccentric member is disposed on one end side in the rotation axis direction, and the cam drive member is disposed on the other end side. A lubricating path for supplying lubricating oil to the sliding portion is provided. For this reason, in a variable valve drive device that can be mounted without significantly changing the engine configuration and the cam working angle can be varied with a simple configuration, lubricating oil is provided to each of the sliding portions of the cam piece and the eccentric member by the lubricating path. Can be efficiently lubricated in parallel. That is, even when the mounted engine is started, the lubricating oil can be efficiently supplied to the sliding portions of the cam piece and the eccentric member with a small time lag.

  As described above, according to the present invention, the sliding portion of the constituent member can be efficiently lubricated in the variable valve driving device that can be mounted without significantly changing the engine configuration and can change the working angle of the cam.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an exploded perspective view of an essential part of an engine provided with a lubricating oil passage of a variable valve drive device according to an embodiment of the present invention.

  An engine 100 shown in FIG. 1 includes an engine main body 110 having a cylinder section 106 and a cylinder head 104 that house a piston 102 so as to be able to advance and retreat, a crankshaft 130 housed in a crankcase 112 (see FIG. 10), a variable valve. Drive device 200.

  Note that the engine 100 provides a periodic phase difference in the rotation of the exhaust cam piece 220 and the intake cam piece 240 by the variable valve drive device 200 disposed substantially parallel to the crankshaft 130, and corresponds to each rotation. Vary the valve timing to open and close. As a result, the valve overlap time is variable corresponding to the engine speed.

  In the present embodiment, engine 100 will be described as a single cylinder SOHC (Single Over Head Camshaft) type mounted on scooter type motorcycle 500 (see FIG. 9). The engine 100 is described as a single-cylinder SOHC type. However, the present invention is not limited to this, and any engine having the variable valve driving device 200 may be used.

  As shown in FIG. 1, the piston 102 in the cylinder portion 106 is disposed so as to be movable back and forth (up and down) in the cylinder axial direction in the cylinder portion 106, and is connected to the base end portion side of the piston 102 via a connecting rod 108. Connected to the crankshaft 130. The connecting rod 108 is rotatably attached to a crank pin (not shown) between the crank webs 132 provided on the crankshaft 130. As a result, the piston 102 moves forward and backward in the cylinder portion 106 as the crankshaft 130 rotates.

  A timing gear 134 is provided on the crankshaft 130 adjacent to the crank web 132 (specifically, the crank journal). A cam drive chain 133 as a drive force transmission member is wound around the timing gear 134. The cam drive chain 133 is wound around a cam sprocket 211 disposed in the cylinder head 104 of the engine main body 110 together with the timing gear 134 to transmit the rotational drive force to the cam pieces 220 and 240 of the variable valve drive device 200. To do.

  The transmission line of the cam drive chain 133 (in this embodiment, the chain line) is substantially perpendicular to the crankshaft 130 and is made to approach the cylinder shaft of the cylinder portion 106 in which the piston 102 moves forward and backward. Placed in position. This is to prevent the bending stress applied to the crank itself from increasing as the cam drive chain 133 is separated from the crank portion that drives the piston 102 due to the structure of the engine. .

  The cam drive chain 133 is disposed in a chain case portion 116 that is integrally provided adjacent to the cylinder portion 106 in the engine main body 110. An upper portion (hereinafter referred to as “case upper portion”) 116 a of the chain case portion 116 is provided in the cylinder head 104, and the case upper portion 116 a opens in the cylinder head 104 in a direction parallel to the crankshaft. One of the openings 116b communicates with the space above the cylinder part 106, and an annular cylinder head cover (hereinafter referred to as “head cover”) 105 is attached to the other opening 116c. One end of the variable valve driving device 200 is disposed on the annular head cover 105, and the variable valve driving device 200 is supported by the head cover 105 on one end thereof.

  The variable valve drive device 200 includes a cam sprocket 211, an exhaust cam piece 220, a variable cam shaft 230, an intake cam piece 240, an eccentric plate (eccentric member) 250, an eccentric boss (member moving portion) 260, and an eccentric motor 270. The cylinder head 104 is attached in parallel with the crankshaft 130.

  FIG. 2 is a cross-sectional view of a main part showing the variable valve driving device 200 attached to the cylinder head 104, and FIG. 3 is an exploded perspective view of the variable valve driving device 200.

  In this variable valve drive device 200, the rotation axes of the cam sprocket 211, the exhaust cam piece 220, the variable cam shaft 230, the intake cam piece 240, the eccentric plate 250, and the eccentric boss 260 are parallel to each other.

  As shown in FIGS. 1 to 3, in the variable valve driving device 200, the intake cam piece 240 and the exhaust cam piece 220 are arranged above the cylinder portion 106 in the cylinder head 104 with the variable cam shaft 230 inserted. Is arranged. The variable cam shaft 230 is inserted into the cam sprocket 211, and the cam sprocket 211 and the eccentric plate 250 are disposed in the case upper portion 116a.

  The eccentric boss 260 is rotatably attached to the annular head cover 105, and the variable valve driving device 200 is fixed to the cylinder head 104 by fixing the head cover 105 to the cylinder head 104.

  As shown in FIGS. 1 to 3, the cam sprocket 211 has the same axis, and is integrated with an exhaust cam piece 220 that opens and closes a valve (here, an exhaust valve) and a cylindrical portion 224 by rotating. Is formed. That is, the cam sprocket 211, the cylindrical portion 224, and the exhaust cam piece 220 form a cam drive body 210 that directly receives the driving force of the crankshaft 130 and rotates.

  The cam sprocket 211 is driven by the drive of the crankshaft 130 via the timing gear 134 (see FIG. 1) and the cam drive chain 133 (see FIG. 1), and rotates at a constant reduction ratio with respect to the rotation speed of the crankshaft 130. To do. Here, the cam sprocket 211 rotates at a speed that is half the rotation of the crankshaft 130.

  The axes of the cam sprocket 211 and the exhaust cam piece 220 are camshaft axes, and the camshaft axes are arranged in parallel with the crankshaft 130 (see FIG. 1) above the cylinder portion 106.

  Further, as shown in FIGS. 1 to 3, the cam sprocket 211 protrudes in the opposite direction to the exhaust cam piece 220 in parallel with the rotation axis direction of the cam sprocket 211 and rotates the eccentric plate 250. A drive pin 212 to be driven is provided. The drive pin 212 is loosely fitted in a slot 252 cut out in the radial direction from the center side of the eccentric plate 250.

  The axis of the drive pin 212 is eccentric with respect to the axis of the cam sprocket 211. When the cam sprocket 211 rotates, the drive pin 212 circulates around the axis of the cam sprocket 211 and the rotation axis is parallel through the slot 252. The eccentric plate 250 is driven to rotate. The cam sprocket 211 is provided with a protruding piece 114 protruding in the radial direction.

  The rotational position of the protruding piece 114 is detected by a sensor 114 a attached to the cylinder head 104.

  Further, since the driving force of the crankshaft 130 is directly transmitted to the cam sprocket 211 via the cam drive chain 133 (see FIG. 1), the rotational position of the cam sprocket 211 is interlocked with the stroke of the crank. That is, the rotation position includes information on the crank stroke (in the case of 4 cycles, the intake stroke, the compression stroke, the explosion stroke, and the exhaust stroke). For this reason, the crank stroke can be determined by detecting the position of the protrusion 114 of the cam sprocket 211 by the sensor 114a.

  Further, an insertion hole 215 that penetrates in the axial direction is provided in the same shaft center portion of each of the cam sprocket 211, the exhaust cam piece 220, and the cylindrical portion 224, that is, the shaft center portion of the cam drive body 210. . The insertion hole 215 communicates with a hole 223 opened in the base circle surface of the exhaust cam piece 220 (see FIG. 2).

  The shaft portion 230a of the variable cam shaft 230 is inserted into the insertion hole 215 so as to be rotatable in the axial direction.

  The shaft portion 230a of the variable cam shaft 230 protrudes on both sides in the axial direction from the inserted cam drive body 210, and an intake cam piece 240 adjacent to the exhaust cam piece 220 is integrated with a portion protruding on the exhaust cam piece 220 side. Attached.

  Further, the variable cam shaft 230 has a follower pin 232 that protrudes on the cam sprocket 211 side of the cam driver 210 in the shaft portion 230a.

  The variable cam shaft 230 is disposed so as to cross over the cylinder portion 106 while being inserted into the cam drive body 210. The variable cam shaft 230 is rotatably supported by the bearing 104a and the bearing 113.

  Further, the variable cam shaft 230 has a through hole 238 that penetrates in the axial direction in the shaft portion 230a, and this through hole 238 is a lubricating oil supplied to the sliding portion of the members in the variable valve drive device 200. It is a lubrication path. Hereinafter, the through hole 238 will be described as the lubrication path 238.

  Specifically, the lubrication path 238 is provided through the rotation shaft of the cam drive body 210 (in particular, the cam sprocket 211), and is provided at the sliding portion of the intake cam piece 240 on the other end side of the cam drive body 210. Supply lubricating oil. The lubricating path 238 supplies lubricating oil to the sliding portion of the eccentric plate 250 on the one end side of the cam driver 210.

  The lubrication path 238 communicates with the outer peripheral surface of the shaft portion 230a through branch oil passages 239a, 239b, and 239c, and is opened to one end surface side through a restriction 235 provided on the chain line side in the shaft portion 230a. ing.

  The lubrication path 238 forms a lubrication oil path 290 in the variable valve drive device 200 together with the branch oil paths 239a, 239b, and 239c.

  The branch oil passages 239a, 239b, and 239c are formed in the shaft portion 230a so as to be orthogonal to the lubrication passage 238, respectively, and open to the outer surface portion of the shaft portion 230a.

  Oil sump grooves 236 and 237 formed in a concave shape in the circumferential direction of the shaft portion 230a are provided in the outer surface portion where the branch oil passages 239a and 239b are opened. The branch oil passages 239a and 239b are formed in the oil sump groove 236. 237.

  These oil sump grooves 236 and 237 are formed in the portion that slides in contact with the inner peripheral surface of the insertion hole 215 constituting the inner peripheral surface portion of the cylindrical portion 224 and the exhaust cam piece 220, and the branched oil passages 239a, It is lubricated by the lubricating oil guided to 239b.

  The branch oil passage 239c is formed in the shaft portion 230a so as to be orthogonal to the lubrication passage 238, and is open to an outer surface portion communicating with the hole portion 245 of the intake cam piece 240.

  Thus, the lubricating oil guided by the branch oil passage 239c is supplied to the sliding portion between the shaft portion 230a and the intake cam piece 240, and lubricates the sliding portion. An oil sump groove 246 is formed in the portion of the intake cam piece 240 that slides on the outer peripheral surface of the shaft portion 230 a along the inner peripheral surface of the opening of the intake cam piece 240.

  One end of the variable cam shaft 230 is inserted into a bearing 113 attached to the cylinder head 104 in the cylinder head 104. A portion protruding from the bearing 113 is covered with an oil seal cap 115, and the oil seal portion 117 prevents the lubricating oil from leaking outside the cylinder head 104.

  An oil pump discharge port 118 is provided on one end of the cylinder head 104. The lubricating oil is press-fitted into the oil reservoir 119 communicating with the opening 230 c at one end of the shaft portion 230 a through the discharge port 118, and is guided into the lubricating path 238 through the oil reservoir 119.

  The intake cam piece 240 is externally fitted to one end side of the shaft portion 230a, and is fixed by fitting a pin 241 into a notch 243 (see FIG. 3) formed in the intake cam piece 240. The intake cam piece 240 is disposed above the cylinder part together with the exhaust cam piece 220.

  When the intake cam piece 240 rotates around the axis of the variable cam shaft 230, the intake cam piece 240 is driven to rotate around the coaxial axis. Further, as shown in FIG. 2, the intake cam piece 240 is formed with a hole 245 that penetrates the base circle surface and the inner surface of the opening that is fitted around one end of the shaft portion 230a. The hole portion 245 communicates with the lubrication path 238 in the shaft portion 230a.

  With this configuration, when the lubricating oil is discharged from the discharge port 118, the lubricating oil in the cylinder head 104 passes through the branch oil passages 239 c, 239 b, and 239 a, and the intake cam piece 240 and the exhaust cam piece 220 respectively. Supplied to the sliding part and the respective cam profile part.

  That is, the lubrication path 238 is formed in the axial direction so as to pass through the shaft portion 230a of the variable cam shaft 230 that is adjacent to the eccentric plate 250 on the other end side and has the intake cam piece 240 attached to one end portion. ing. In other words, the lubrication path 238 passes through the intake cam piece 240 and the exhaust cam piece 220 and also passes through the cam sprocket 211 adjacent to the exhaust cam piece 220 to reach the eccentric plate 250.

  Furthermore, in other words, the lubrication path 238 passes through the cam sprocket 211 from one end side in the variable cam shaft 230 on which the intake cam piece 240, the exhaust cam piece 220, and the cam sprocket 211 are externally fitted in order from one end side. The other end is opened through a diaphragm 235.

  The restrictor 235 is a lubricating oil supplied to the valve drive part (exhaust cam piece 220, intake cam piece 240) side and variable mechanism part (eccentric plate 250, drive pin 212, driven pin 232, slots 252, 254, etc.) side. Distribute the amount optimally.

  As described above, the lubricating path 238 crosses the cylinder head 104 at the upper portion of the cylinder portion 106. As a result, the lubricating oil supplied from the one end side of the shaft portion 230a passes over the cam sprocket 211 that is directly driven by the crankshaft 130 to the eccentric plate 250 on the other end side of the shaft portion 230a via the throttle 235. Flowing.

  A plate 234 protruding perpendicularly to the axis of the shaft portion 230a is attached to the other end portion side of the shaft portion 230a. The plate 234 rotates at a position adjacent to the cam sprocket 211 as the shaft portion 230a rotates.

  The plate 234 is provided with a driven pin 232 that protrudes in a direction opposite to the direction in which the shaft portion 230a extends (see FIGS. 1 to 3).

  The driven pin 232 is positioned parallel to the shaft center of the shaft portion 230a and eccentric from the shaft center of the shaft portion 230a, and is disposed opposite to the drive pin 212 with the shaft portion 230a interposed therebetween.

  In the eccentric plate 250, the driven pin 232 is loosely fitted in a slot 254 that is notched in the radial direction from the center of the eccentric plate 250, and rotates around the shaft center of the shaft portion 230a by the rotation of the eccentric plate 250. To do. That is, when the drive pin 212 that rotates with the rotation of the cam sprocket 211 drives the eccentric plate 250 to rotate, the intake cam piece is accompanied by the rotation of the variable cam shaft 230 driven by the rotation of the eccentric plate 250 via the driven pin 232. 240 also rotates.

  The eccentric plate 250 is provided with a plate shaft portion 258 at the center of a plate-like plate body portion 256 disposed adjacent to the plate 234 of the variable cam shaft 230, and the plate body portion 256 sandwiches the plate shaft portion 258. A slot 252 and a slot 254 in which the drive pin 212 and the driven pin 232 are loosely fitted are formed on the same straight line.

  The plate shaft portion 258 is provided so as to protrude perpendicular to the plate body portion 256 and on the opposite side of the plate 234, and is rotatably inserted into an eccentric hole 262 formed in the eccentric boss 260. .

  The eccentric hole 262 is formed in an eccentric boss main body 264 that is rotatably disposed inside the head cover 105 attached to the cylinder head 104 at a position that is eccentric with respect to the rotation center R (see FIG. 3). A rack 266 provided on a part of the outer periphery of the boss main body 264 is meshed with a worm gear 272 of an eccentric motor 270 attached to the head cover 105. Therefore, by driving the eccentric motor 270, the position of the eccentric hole 262 can be moved to an eccentric position with respect to the rotation center R (see FIG. 3) of the boss body 264.

  That is, the eccentric boss 260 is disposed adjacent to the eccentric plate 250 on the side opposite to the cam sprocket 210, and the plate shaft portion 252 of the eccentric plate 250 is moved from the coaxial position to the eccentric position with respect to the rotation axis of the cam sprocket 211. Move to

  FIG. 4 is a diagram showing a positional relationship among the rotation center R of the eccentric boss 260, the axis C of the variable cam shaft 230, and the axis E of the eccentric plate 250.

  As shown in FIG. 4, the eccentric boss 260 is rotatably fitted in the head cover 105, and is rotated around a rotation center (boss center) R by an eccentric motor 270 (see FIGS. 1 to 3). The rotation center R is fixed on the engine side, and is the rotation center in which the axis (eccentric center) E rotates with respect to the rotation axis C of the variable cam shaft 230, the exhaust cam piece 220, and the intake cam piece 240. Yes.

  Since the plate shaft portion 258, that is, the shaft center E of the eccentric plate 250 is rotatably inserted into the eccentric hole 262 of the eccentric boss 260, the shaft center (the center of eccentricity) of the eccentric plate 250 is rotated by the rotation of the eccentric boss 260. ) E moves in an arc shape around the rotation center (boss center) R. Further, on the movement line of the shaft center E, the shaft center C of the variable cam shaft 230, that is, the shaft centers C of the exhaust cam piece 220 and the intake cam piece 240 are arranged.

  By rotating about the boss center R of the eccentric boss 260, the shaft center E of the eccentric plate 250 is eccentric with the axis C of the variable cam shaft 230, and the exhaust cam piece 220 integrated with the cam sprocket 211 is rotated. On the other hand, a phase difference can be provided in the rotation of the intake cam piece 240 integral with the variable cam drive shaft.

  Further, the rotation of the eccentric boss 260 allows the axis E and the axis C to coincide. The eccentric boss 260 is fixed at a position where the axis E and the axis C coincide with each other, that is, a position where the axis E of the eccentric hole 262 in the eccentric boss 260 and the position of the axis C in the variable cam shaft 230 overlap. it can. Thereby, the eccentric plate 250 and the variable cam shaft 230 can be rotated around the same axis.

  The rotational angle position of the eccentric boss 260 in the head cover 105 is detected by angle sensor units 26 and 27 provided on the eccentric boss 260 as shown in FIG. Using the information detected in this way, information obtained from the engine side such as engine rotation and engine load, and information input from the user via an operation unit (not shown), the eccentric position of the eccentric hole 262 is It is controlled to a preset position by a control unit (not shown).

  Here, the structure of the eccentric boss 260 will be described.

  FIG. 5 is an exploded perspective view of the eccentric boss.

  As shown in FIG. 5, the eccentric boss body 264 of the eccentric boss 260 is formed by attaching a lid 264b to a body case 264a having a bottomed cylindrical shape and having an eccentric hole 262 formed therein.

  The main body case 264a is provided with compartments 267a, 267b, 267c partitioned by partition walls 265a, 265b, 265c around the eccentric hole 262.

  An air hole 268 that communicates the compartment 267 with the back side of the eccentric boss, that is, the eccentric plate 250 side, is provided in the bottom surface portion of the compartment 267a. An oil return hole 268a that communicates with the outside of the eccentric boss main body 264 is formed in the peripheral wall of the compartment 267a.

  Further, the partition walls 265a and 265b are provided with a notch 269, and the compartment 267a and the compartment 267b and the compartment 267b and the compartment 267c communicate with each other.

  The lid portion 264b covers the compartments 267a, 267b, 267c. The lid 264b has an opening 264c at the ceiling of the compartment 267c.

  Thus, the eccentric boss 260 is configured to communicate with the axial direction, that is, the front and back surfaces via the air hole 268, the compartments 267a, 267b, 267c, the notch 269, and the opening 264c. In other words, the eccentric boss 260 is provided with compartments 267a, 267b, and 267c as hollow portions communicating with the cam sprocket 211 in the rotation axis direction.

  That is, the eccentric boss 260 communicates with the inside and outside of the head cylinder while being attached to the cylinder head 104 via the head cover 105.

  An oil return hole 105 a is formed in the head cover 105 in parallel with the rotational axis of the eccentric boss 260. Thus, when the lubricating oil from the eccentric plate 250 side flows into the eccentric boss 260, the lubricating oil is returned to the engine 100 together with the oil return hole 268a communicating with the inside of the compartment 267a. That is, the compartments 267 a, 267 b, and 267 c function as breather chambers that prevent the lubricating oil in the blow-by gas generated in the engine 100 from being discharged outside the engine 100.

  Next, the operation of the variable valve drive apparatus 200 in the present embodiment will be described.

  In the variable valve drive apparatus 200 shown in FIGS. 1 to 3, the cam sprocket 211 is driven by the rotation of the crankshaft 130 by a half of the rotation of the crankshaft 130 through the cam drive chain 133. The exhaust cam piece 220 provided integrally with the cam sprocket 211 via the cylindrical portion 224 is driven to rotate. That is, the exhaust cam piece 220 rotates in synchronization with the rotation of the crankshaft 130.

  Further, by the rotation of the cam sprocket 211, the drive pin 212 loosely fitted in the slot 252 of the eccentric plate 250 presses the eccentric plate 250 around the plate shaft portion 258 via the slot 252, and the eccentric plate 250 is Rotate. Since the center of rotation of the eccentric plate 250, that is, the position of the plate shaft portion 258 is decentered by driving the eccentric motor 270, the eccentric plate 250 is unequal even when the cam sprocket 211 is rotating at a constant speed. It rotates at high speed.

  FIG. 6 is a diagram illustrating an example of a positional relationship between the drive pin and the driven pin in a state where the center of the eccentric plate is eccentric with respect to the cam shaft in the variable valve driving device. FIGS. 6A to 6I show the relative positional relationship between the drive pin 212 and the driven pin 232 in a stepwise manner when the crankshaft is rotated at a predetermined rotation. In addition, since slots 252 and 254 (see FIGS. 1 and 3) in which the drive pin 212 and the driven pin 232 are loosely fitted are formed on the same straight line, they are schematically shown as a straight line SL.

  When the drive pin 212 is located on the center (rotation axis) E side of the eccentric plate 250 with respect to the axis C of the cam sprocket 211, the distance between the center of the eccentric plate 250 and the center of the drive pin 212 is the distance from the center of the cam sprocket 211. It is smaller than the distance between the pin centers. Therefore, the rotation angle of the eccentric plate 250 is larger than the rotation angle of the cam sprocket 211.

  On the other hand, when the drive pin 212 is on the opposite side, that is, on the side away from the center of the eccentric plate 250 with respect to the axis C of the cam sprocket 211, the distance between the center of the eccentric plate 250 and the center of the drive pin 212 is It becomes larger than the distance between the sprocket shaft center C and the drive pin center. Therefore, the rotation angle of the eccentric plate 250 is smaller than the rotation angle of the cam sprocket 211.

  Further, the slot 254 formed in the plate main body portion 256 of the eccentric plate 250 rotates at an unequal speed similarly to the eccentric plate 250. Since the driven pin 232 loosely fitted in the slot 254 is concentric with the cam sprocket 211 and the intake cam piece 240, the inconstant speed motion is transmitted to the driven pin 232 via the slot 254. Through the driven pin 232 to which the inequality motion is transmitted, the shaft portion 230a rotates at an unequal speed, and accordingly, the intake cam piece 240 rotates at an unequal speed.

  For example, it is assumed that the intake cam piece 240 is driven at a faster angular speed that is ½ the crank in the vicinity of the crank angle at which the intake cam piece 240 is open. At this time, when the crank rotates by the operating angle (for example, 268 degrees), the cam rotates more than the operating angle, so the intake valve is opened and closed in a shorter time. That is, the operating angle is narrowed. On the other hand, when the intake cam rotates slowly, the working angle can be widened.

  As described above, in the variable valve driving device 200, the rotational position of the intake cam piece 240 rotated by the variable cam shaft 230 driven via the eccentric plate 250 with respect to the exhaust cam piece 220 provided integrally with the cam sprocket 211. The phase difference fluctuates periodically. That is, the operating angle of the intake cam piece 240 is periodically variable. In other words, the intake cam piece 240 rotates at an unequal speed, and the operating angle and opening / closing timing of an intake valve (variable valve) that opens and closes by this rotation change. .

  The timing at which the intake cam piece 240 is rotated fast with respect to the exhaust cam piece 220 and at which timing is rotated slowly depends on the center of the eccentric plate 250, the cam nose, and the slots 252 and 254 with respect to the center of the cam sprocket 211. Determined by the positional relationship.

  FIG. 7 is a diagram illustrating an example of a valve lift by the variable valve driving device according to the present embodiment. In FIG. 7, the lift amount of the intake valve is indicated by a lift curve K, and the lift amount of the exhaust valve is indicated by a lift curve H. Further, the opening timing of the variable valve (here, the intake valve) is indicated by OT, OT1, and OT2, and the closing timing is indicated by TT, TT1, and TT2. Further, FIG. 7 illustrates the working angle (also referred to as “operation angle”) D1, the valve overlap D2, and the maximum lift angles D3 and D4 of the intake cam piece.

  As shown in FIG. 7, in the variable valve drive device 200, when the eccentric boss 260 is rotationally driven, the position of the eccentric hole 262, that is, the rotational center of the eccentric plate 250 is eccentric with respect to the cam shaft. Is variable as shown by lift curves K1, K2.

  Specifically, when the cam operating angle (the length from the opening timing OT1 to the closing timing TT1) is increased as in the lift curve K1, the cam rotation speed is reduced while the valve is open, and the valve is closed. The cam rotation speed increases.

  Further, when the cam operating angle (length from the opening timing OT2 to the closing timing TT2) is reduced as in the lift curve K2, the cam rotation speed increases while the valve is open, and when the valve is closed, The rotation speed drops.

  In this manner, the intake cam piece 240 can be rotated with a periodic rotational phase difference provided with respect to the exhaust cam piece 220, and the rotational phase difference can be changed as appropriate. The length can be varied with engine stroke.

  Therefore, the overlap is controlled, and at the time of idling, the valve is opened / closed early by the intake cam piece 240 to reduce or eliminate the overlap, thereby suppressing the mixing of residual gas (combustion gas) and gas combustion. Can be stabilized. In addition, it is possible to reduce the scavenging and blow-back of residual gas due to the exhaust pulsation effect, and further improve the intake effect of the air-fuel mixture to inhale sufficient air-fuel mixture to stabilize idling and startability Can be improved.

  Further, it is possible to prevent blow-through and reduce exhaust gas, and to increase the engine output at the time of low engine rotation and improve fuel efficiency.

  In particular, when the engine is running at a low speed, the intake cam piece 240 is rotated so that the intake valve is fully closed when the piston 102 is located at the bottom dead center.

  In addition, when the engine is running at medium speed (medium load range), it is possible to reduce the pumping loss by widening the intake valve early to increase the overlap, thereby improving combustion efficiency and improving fuel efficiency. it can.

  By the way, in the variable valve drive device 200, the lubricating oil is efficiently supplied to the sliding portion of the member.

  FIG. 8 is a diagram showing the flow of the lubricating oil in the lubricating oil path of the variable valve drive apparatus 200 according to the embodiment of the present invention.

  As shown in FIG. 8, the lubricating oil pumped up from the oil pan 620 (see FIG. 9) by a pump (not shown) at one end portion of the shaft portion 230 a arranged in the front-rear direction and substantially horizontally of the cylinder head 104 is It is discharged from the discharge port 118.

  Lubricating oil from the discharge port 118 flows into the oil reservoir 119 in the gasket 111 disposed on one end 111 (end on the cylinder 106 side) of the sealed cylinder head 104 (in the direction of arrow S1 in FIG. 8). To do. The inflowing lubricating oil flows into the lubricating path 238 in the shaft portion 230a from the one end opening 230c of the rotating shaft portion 230a in the oil reservoir 119 (in the direction of arrow S2 in FIG. 8).

  The lubricating oil that has flowed into the lubricating path 238 flows toward the chain line side of the shaft portion 230a. The lubricating oil passes through the branch oil passage 239c and flows out of the intake cam piece 240 from the hole 245 (in the direction of arrow S3 in FIG. 8), and reduces friction at the sliding portion of the intake cam piece 240.

  The lubricating oil in the lubricating path 238 flows from the branch oil path 239b into the oil sump groove 237 and lubricates the sliding portion with the exhaust cam piece 220 (in the direction of arrow S4 in FIG. 8). Further, the lubricating oil (in the direction of arrow S4 in FIG. 8) from the branch oil passage 239c lubricates the base circle surface of the exhaust cam piece 220 from the hole 223.

  Further, the lubricating oil in the lubricating passage 238 flows into the oil sump groove 236 from the branch oil passage 239a, and lubricates the sliding portion between the cylindrical portion 224 and the bearing 104a provided in the cylinder head 104 (FIG. 8). Arrow S5 direction).

  Then, the lubricating oil in the lubricating path 238 further flows to the chain line side of the shaft portion 230a, and flows out from one end surface of the shaft portion 230a, specifically, from the axial center portion of the surface of the plate 234 to the outside through the restrictor 235. (See arrow S6 in FIG. 8).

  Since this plate 234 is disposed opposite to the eccentric plate 250 in the chain case portion 116 of the cylinder head 104, the lubricating oil from the lubrication path 238 lubricates the sliding portion with other members related to the eccentric plate 250. To do. For example, the lubricating oil discharged from the variable cam shaft 230 lubricates the plate body portion 256 (slots 252 and 254), the sliding portions of the drive pin 212 and the driven pin 232 (in the directions of arrows S7 and S8 in FIG. 8), and the like. .

  Further, the lubricating oil lubricates the sliding portion between the cam sprocket 211 and the cam drive chain 133 (see FIG. 1) (in the directions of arrows S9 and S10 in FIG. 8).

  Lubricating oil can be efficiently lubricated in parallel to the sliding portions of the exhaust cam piece 220, the intake cam piece 240, and the eccentric plate 250 by the lubrication path 238. That is, even when the mounted engine is started, the lubricating oil can be efficiently supplied to the sliding portions of the exhaust cam piece 220, the intake cam piece 240, and the eccentric plate 250 with little time lag.

  Further, the variable valve driving device 200 has a positional relationship between the exhaust and intake cam pieces 220 and 240 and the cam sprocket 211 on the cam axis as compared with a variable valve driving mechanism, that is, a cam shaft without a so-called variable bubble timing mechanism. Will not change.

  Therefore, in a conventional motorcycle having no variable valve drive mechanism, particularly an engine structure of a scooter, the variable valve drive device 200 can be mounted only by changing the camshaft portion to the variable valve drive device 200.

  Specifically, in order to mount the variable valve driving device 200, the dimensions, arrangement positions, etc. of each member are changed in order to drive the camshafts such as the crankshaft, the cylinder portion and cylinder head of the engine body, and the timing gear. There is no.

  Therefore, in the engine 100, when it is desired to make the intake cam piece 240 not to rotate due to the periodic rotational phase difference with respect to the exhaust cam piece 220, first, the variable valve driving device 200 and the head cover 105 are installed. Remove from engine body 110. Then, there is no variable mechanism portion such as the eccentric plate 250, and a crankshaft having a cam sprocket, an exhaust cam piece, an intake cam piece and the like is inserted into the cylinder head, and a head cover formed corresponding to the crankshaft is attached. Thereby, the motorcycle including the variable valve driving device 200 can be easily changed to a motorcycle not including the variable valve driving device 200.

  Next, a vehicle equipped with an engine 100 according to an embodiment of the present invention will be described.

  Here, the vehicle on which the engine 100 is mounted will be described as a scooter type motorcycle. However, the present invention is not limited to this, and any vehicle on which the engine 100 is mounted may be used.

  FIG. 9 is a schematic side view showing a main part configuration of a motorcycle including a variable valve drive device for an engine according to an embodiment of the present invention. In the present embodiment, front, rear, left, and right mean front, rear, left, and right when viewed in a seated state on the motorcycle seat. Although the motorcycle according to the present embodiment is described as a scooter type motorcycle, the present invention is not limited to this, and any vehicle may be used as long as the vehicle has a valve driving device.

  A motorcycle 500 shown in FIG. 9 is a tandem scooter type, and includes a tandem seat 504 on the rear side of a vehicle body 503 that rotatably supports a handle 502 on the front side. The tandem seat 504 is attached to the trunk space 505 arranged at the lower part so as to be freely opened and closed. A drive unit 600 is disposed below the trunk space 505.

  The front end portion of the drive unit 600 has a pivot shaft (not shown) horizontally disposed in the vehicle width direction at the rear end portion of the front main body 503a extending from the lower side of the handle 502 to the lower side of the tandem seat 504. It is attached so that it can swing up and down.

  A rear wheel 508 is attached to the rear end portion of the drive unit 600 via an axle 510, and a rear suspension 512 is provided between the rear end portion and a frame pivot that supports the rear end portion of the trunk space 505. Suspended. A front end portion of the trunk space 505 is disposed in front of the front end portion of the drive unit 600.

  FIG. 10 is a schematic plan view showing a main part of the drive unit of FIG.

  As shown in FIG. 10, in drive unit 600, engine 100 is mounted on the front side of the vehicle, and driving force of engine 100 is transmitted to axle 510 disposed at the rear end of drive unit 600 via CVT mechanism 610. The rear wheel 508 is rotated by being driven to rotate.

  The engine 100 is positioned at a substantially central portion in the vehicle front-rear direction below the trunk space 505 with the axis of the cylinder portion 106 made substantially horizontal and the crankshaft 130 made substantially parallel to the vehicle width direction.

  A CVT mechanism portion 610 extending rearward of the vehicle is disposed on the other end portion side of the crankshaft 130, here, on the left end portion of the vehicle. The CVT mechanism 610 is arranged in parallel with the cylinder shaft, and includes a pulley 611 attached to the crankshaft 130, a pulley 612 attached to the axle 510, a belt 613 stretched between these pulleys 611 and 612, and a centrifugal clutch 614.

  The centrifugal clutch 614 is attached to the axle shaft 510. A reduction gear 615 is attached to the axle 510 to reduce the driving force of the crankshaft 130 transmitted via the pulley 611 and the belt 613.

  In motorcycles, it is conceivable to install a variable valve timing mechanism due to exhaust gas regulation problems, etc. In particular, in a scooter type vehicle (hereinafter referred to as “scooter”), the engine structure is limited due to vehicle size limitations. It is desirable to be simplified.

  Engine 100 according to the present embodiment has an eccentricity between cam drive body 210 corresponding to the cam drive shaft in the conventional engine configuration and exhaust and intake cam pieces 220 and 240 arranged on the upper portion of cylinder portion 106. The eccentric plate 250 corresponding to the member is not arranged.

  In the engine 100, an eccentric plate 250 and exhaust and intake cam pieces 220 and 240 are arranged on the cam axis with the cam drive body 210 interposed therebetween.

  That is, the eccentric plate 250 and the exhaust and intake cam pieces 220 and 240 are disposed on the cam axis with the cam sprocket 211 disposed on the chain line of the cam drive chain 133 interposed therebetween.

  Since the exhaust and intake cam pieces 220 and 240 are arranged on the upper part of the cylinder portion 106 along the cylinder axis CL due to the engine structure, unlike the conventional configuration, the cylinder axis and the cam chain line are arranged at adjacent positions. It has an established structure.

  For this reason, as shown in FIG. 10, the chain line L of the engine 100 is compared with the chain line LA in the case of the conventional configuration in which the eccentric member is disposed between the cam sprocket 211 and the exhaust and intake cam pieces 220 and 240. Thus, it is disposed at a position close to the cylinder axis CL.

  As a result, the belt 613 line of the CVT mechanism 610 disposed outside the chain line L and in parallel with the chain line L is closer to the cylinder axis CL than in the conventional structure.

  Therefore, the lateral width of the drive unit 600 itself is reduced. Specifically, in the drive unit 600, the left end surface 600a is closer to the right side surface than the left side surface 600b when the engine equipped with the variable valve driving device of the conventional configuration is mounted, as the chain line L approaches the cylinder axis CL. approach.

  That is, the scooter type motorcycle 500 is structurally provided with components provided outside the cam drive chain 133 on the crankshaft such as a sheave for CVT (Continuously Variable Transmission).

  In the engine 100 mounted on such a motorcycle 500, a member for driving a variable valve is not provided between the chain line L of the cam drive chain 133 and the cylinder axis CL on the cam shaft. Accordingly, it is not necessary to provide a space corresponding to the member on the crankshaft 130, and the cam sprocket 211 and the cam pieces 220 and 240 are separated from each other as compared with an engine having a conventional variable valve timing mechanism. do not do.

  In other words, the chain line L of the cam drive chain 133 arranged substantially orthogonal to the crankshaft 130 does not separate from the cylinder axis CL.

  As a result, the motorcycle 500 has the same crankcase 112 width as the structure without the variable valve timing mechanism.

  Therefore, it is possible to obtain a sufficient bank angle in the motorcycle 500, to prevent a reduction in vehicle motion characteristics, and to ensure vehicle mobility.

  Further, in the variable valve driving device 200, the eccentric mechanism portion such as the eccentric plate 250 is not disposed between the exhaust and intake cam pieces 220 and 240 and the cam sprocket 211. For this reason, in the engine 100, components other than the variable valve driving device 200 can use substantially the same components as those of the engine that does not include the variable valve driving device 200. That is, the variable valve driving device 200 is removed from the cylinder head 104 of the engine main body 110 and only the eccentric plate 250, the variable cam shaft 230, the eccentric boss 260, and the head cover 105 are changed, and the variable valve driving device 200 is not provided. It can be used as an engine.

  Therefore, even when mounted on a motorcycle, there is no need to change the structure significantly compared to the conventional engine, and the main engine components such as the cylinder head are shared between the conventional engine and the non-variable engine. Can be.

  In addition, since an eccentric mechanism such as an eccentric plate is not disposed between the cam sprocket and the camshaft in the engine, the reduction in the bending strength of the crank that occurs when the camsprocket is separated from the cylinder shaft may be reduced. Absent.

  Further, unlike the structure in which the cam drive shaft itself is moved in the axial direction, the overlap period can be changed with a simple configuration.

  Thus, in the present embodiment, it is possible to realize high response and low fuel consumption in the engine by changing the cam operating angle with a simple configuration without significantly changing the engine configuration.

  In the present embodiment, engine 100 is of a single cylinder SOHC (Single Over Head Camshaft) type, but is not limited thereto, and is applicable to a multi-cylinder SOHC type and DOHC (Double Over Head Camshaft).

  In the variable valve driving device 200, the rotational phase difference of the intake cam piece 240 is periodically changed with respect to the exhaust cam piece 220 in order to vary the working angle of the intake valve. Absent. That is, the rotational phase difference of the exhaust cam piece 220 may be periodically changed with respect to the intake cam piece 240. In this case, in the variable valve driving device 200, an intake cam piece for driving the intake valve is provided by rotating integrally with the cam sprocket 211, and an exhaust cam piece for driving the exhaust valve is provided on the variable cam shaft 230. The configuration is as follows. With this configuration, by changing the working angle of the exhaust valve, the overlap can be changed, and the same effects as described above can be obtained.

  The lubricating oil passage of the variable valve drive device according to the first aspect of the present invention is disposed adjacent to a cam drive member that is rotationally driven by a drive force transmitted from a crankshaft, and one end side of the rotary shaft of the cam drive member. An eccentric member that is rotated about an axis in the same direction as the rotation axis of the cam drive member by the drive of the cam drive member, and that the shaft is movable from an axial position of the rotation shaft to an eccentric position. And a rotational phase difference with respect to the cam drive member when the eccentric member is rotationally driven at the eccentric position by the eccentric member. Is arranged on the other end portion side of the rotating shaft of the cam driving member, and is driven to rotate at the same rotational phase as the cam shaft by the cam shaft to drive an exhaust or intake valve. A lubricating oil passage of a variable valve drive device including a piece, provided through the rotation shaft of the cam drive member, and lubricating oil on a sliding portion of the cam piece on the other end side of the cam drive member. A configuration is adopted in which a lubricating path is provided for supplying lubricating oil to the sliding portion of the eccentric member on the one end side of the cam driving member while supplying the lubricating oil.

  A cam piece that rotates at the same rotation phase as the cam shaft is driven by a rotation phase difference with respect to the cam drive member that varies periodically. That is, the operating angle of the cam piece is variable, thereby driving the exhaust valve or the intake valve, and the operating angle of the exhaust valve or the intake valve is variable. By making the operating angle of the exhaust valve or intake valve variable, the valve overlap is variable.

  Thereby, it can use for the engine with the same displacement, and can shorten an overlap at the time of low rotation (including idling) and high rotation of the engine. More specifically, at low revolutions including idling, the valve is opened and closed early to reduce or eliminate the overlap, thereby suppressing the mixing of residual gas (combustion gas) and stabilizing gas combustion.

  In addition, it is possible to reduce residual gas scavenging and blowback due to the effect of exhaust pulsation, and to stabilize idling and improve startability. Further, blowout can be prevented and exhaust gas can be reduced, and the engine output at the time of low engine rotation can be increased to improve fuel efficiency.

  In addition, when the engine is rotating at medium speed, it is possible to improve the combustion by reducing the pumping loss by increasing the overlap. As described above, the engine performance can be improved by using the variable valve driving device without changing the displacement.

  Further, the eccentric member is not disposed between the cam driving member and the cam piece, and the positional relationship between the exhaust or intake valve and the cam driving member is adjacent to each other as in the conventional engine.

  For this reason, the variable valve driving device having the lubricating oil passage can be mounted without significantly changing the conventional engine configuration. That is, the main engine components can be made common to an engine with a variable valve mechanism and an engine without a variable valve mechanism. Therefore, when this variable valve drive device is mounted on an engine without a variable valve mechanism mounted on a motorcycle, it is not necessary to change other engine components such as a cylinder and a crankshaft, and the cost is greatly reduced. it can.

  In addition, even when an engine equipped with this variable valve drive device is mounted on a motorcycle, in particular a scooter, with the crankshaft disposed in the vehicle width direction, no eccentric member is disposed between the cam drive member and the cam piece. Therefore, the crankshaft width does not increase correspondingly. Specifically, when an eccentric member is provided between the cam drive member and the cam piece, the drive force transmission line from the crankshaft to the cam drive member is accordingly separated from the cylinder axis on which the cam piece is arranged. become.

  As a result, even when transmission means for transmitting the driving force from the crankshaft to the axle is provided outside the driving force transmission line, the transmission means does not protrude outward and the width of the engine itself does not increase. The bank angle can be prevented from decreasing and the vehicle performance can be prevented from decreasing.

  Then, an eccentric member is disposed on one end side in the rotation axis direction, and a cam drive member is disposed on the other end side. The cam drive member includes a sliding portion and a sliding portion of the eccentric member. And a lubricating path for supplying lubricating oil.

  For this reason, in a variable valve drive device that can be mounted without significantly changing the engine configuration and the cam working angle can be varied with a simple configuration, lubricating oil is provided to each of the sliding portions of the cam piece and the eccentric member by the lubricating path. Can be efficiently lubricated in parallel. That is, even when the mounted engine is started, the lubricating oil can be efficiently supplied to the sliding portions of the cam piece and the eccentric member with a small time lag.

  The lubricating oil passage of the variable valve driving device according to the second aspect of the present invention has the above-described configuration, and the lubricating oil is supplied to the lubricating passage from a discharge port of an oil supply pump provided on the other end portion side of the cam driving member. Take the supplied configuration.

  According to this configuration, since the lubricating oil is supplied to the lubricating path from the discharge port of the oil supply pump provided on the other end side of the cam drive member, the lubricating oil supplied from the discharge port passes through the lubricating path. The cam drive member flows from the other end side to the one end side. Therefore, it is possible to lubricate both the sliding portion of the cam piece and the sliding portion of the eccentric member simply by supplying the lubricating oil to the lubricating path.

  The lubricating oil passage of the variable valve driving device according to the third aspect of the present invention is the above-described configuration, wherein the lubricating passage opens to one end portion side of the cam driving member and from the other end portion side of the cam driving member. A configuration having a throttle portion for adjusting the amount of lubricating oil supplied to the sliding portion of the eccentric member is adopted.

  According to this configuration, the lubrication path has a throttle portion that opens to one end of the cam drive member and adjusts the amount of lubricating oil supplied from the other end of the cam drive member to the sliding portion of the eccentric member. Therefore, it is possible to adjust the amount of lubricating oil flowing in the lubricating path by the throttle portion and supply suitable lubricating oil to each sliding portion (sliding portion between members) to prevent wear and to operate smoothly. .

  The lubricating oil passage of the variable valve driving device according to the fourth aspect of the present invention is arranged at a position adjacent to the cam piece while rotating in the same rotational phase as the cam driving member by the cam driving member in the above configuration. The lubricating path is formed through the rotation shaft of the another cam piece, branches off from the lubricating path, and supplies lubricating oil to the sliding portion of the other cam piece. The structure where the branch oil path to perform is provided is taken.

  According to this configuration, the branch oil passage branched from the lubrication passage supplies the lubricant to the sliding portion of another cam piece disposed at a position adjacent to the cam piece. For this reason, in the variable valve drive device that periodically varies the rotational phase difference in another cam piece with respect to the cam piece that rotates at the same rotational phase as the cam drive member, the cam piece and the sliding portion in the other cam piece It is possible to prevent the wear and prevent the wear.

  The lubricating oil passage of the variable valve driving device according to the fifth aspect of the present invention has the above-described configuration, wherein the cam shaft is rotatably inserted through the rotating shaft of the cam driving member, and the lubricating passage is connected to the cam shaft. An outer surface formed through the shaft center of the cam shaft having a coaxial center with the rotating shaft, and is branched from the main passage inside the cam shaft and slides on the cam drive member A configuration is adopted in which a branch passage for supplying lubricating oil is formed.

  According to this configuration, the lubrication path is formed through the cam shaft that is rotatably inserted through the rotation shaft of the cam drive member, and a branch path that branches from the main passage is formed on the peripheral wall of the cam shaft. ing. For this reason, lubricating oil that flows in one direction in the lubricating path is supplied to the outer surface that slides on the cam drive member via the branch path, and lubricates the sliding part during rotation to prevent wear. Can do.

  The lubricating oil passage of the variable valve driving device according to the sixth aspect of the present invention, in the above-described configuration, is disposed adjacent to the eccentric member on the side opposite to the cam driving member, and the shaft of the eccentric member is A member moving part that moves from a coaxial position to an eccentric position with respect to the rotation axis of the cam drive member is provided, and a hollow part that communicates in the direction of the rotation axis is provided in the member moving part.

  According to this configuration, since the hollow member that communicates in the direction of the rotation axis is provided in the member moving part that is disposed adjacent to the eccentric member on the side opposite to the cam drive member, the hollow part is disposed in the breather chamber. Can function as. In addition, when the member moving portion is fixed to the cylinder head and the variable valve driving device is mounted in the cylinder head, the inside and outside of the cylinder head can be communicated. Thereby, the part connected to a hollow part can be functioned as an oil return hole.

  A variable valve drive device according to a seventh aspect of the present invention is arranged adjacent to a cam drive member that is rotationally driven by a drive force transmitted from a crankshaft, and at one end of the rotary shaft of the cam drive member, An eccentric member that rotates about a shaft in the same direction as the rotation axis of the cam drive member by driving the drive member, and the shaft is movably provided from an axial position of the rotation shaft to an eccentric position, and the rotation It is arranged coaxially with the shaft, and is rotationally driven around the rotational shaft by the eccentric member, and when the eccentric member is rotationally driven at the eccentric position, a rotational phase difference with respect to the cam drive member is periodically A cam shaft that is arranged on the other end side of the rotating shaft of the cam drive member, is driven to rotate at the same rotational phase as the cam shaft by the cam shaft, and drives an exhaust or intake valve; The cam drive member is disposed so as to pass through the rotation shaft, supplies lubricating oil to the sliding portion of the cam piece on the other end side of the cam drive member, and the eccentric member on the one end side of the cam drive member. A configuration including a lubricating path for supplying lubricating oil to the sliding portion is adopted.

  The cam piece drives the exhaust valve or the intake valve by driving a cam shaft that is driven by a rotational phase difference with respect to the cam drive member periodically changing, and varies the operating angle of the exhaust valve or the intake valve. The valve overlap can be varied by varying the operating angle of the exhaust valve or the intake valve.

  Thereby, it can use for the engine with the same displacement, and can shorten an overlap at the time of low rotation (including idling) and high rotation of the engine. More specifically, at low revolutions including idling, the valve is opened and closed early to reduce or eliminate the overlap, thereby suppressing the mixing of residual gas (combustion gas) and stabilizing gas combustion.

  In addition, it is possible to reduce residual gas scavenging and blowback due to the effect of exhaust pulsation, and to stabilize idling and improve startability. Further, blowout can be prevented and exhaust gas can be reduced, and the engine output at the time of low engine rotation can be increased to improve fuel efficiency.

  Further, at the time of engine medium speed rotation, a large overlap can reduce the pumping loss and improve the combustion. Thus, the engine performance is improved without changing the displacement.

  In the present variable valve drive device, the eccentric member having such an action is not disposed between the cam drive member and the cam piece, and the positional relationship between the exhaust or intake valve and the cam drive member is the same as that of the conventional engine. It is a positional relationship.

  For this reason, this variable valve drive device can be mounted without significantly changing the conventional engine configuration. That is, the main engine components can be made common to an engine with a variable valve mechanism and an engine without a variable valve mechanism.

  Therefore, when this variable valve drive device is mounted on an engine without a variable valve mechanism mounted on a motorcycle, it is not necessary to change other engine components such as a cylinder and a crankshaft, and the cost can be greatly reduced. .

  In addition, even when an engine equipped with this variable valve drive device is mounted on a motorcycle, in particular a scooter, with the crankshaft disposed in the vehicle width direction, no eccentric member is disposed between the cam drive member and the cam piece. Therefore, the crankshaft width does not increase correspondingly. Specifically, when an eccentric member is provided between the cam drive member and the cam piece, the drive force transmission line from the crankshaft to the cam drive member is accordingly separated from the cylinder axis on which the cam piece is arranged. become.

  As a result, even when transmission means for transmitting the driving force from the crankshaft to the axle is provided outside the driving force transmission line, the transmission means does not protrude outward and the width of the engine itself does not increase. The bank angle can be prevented from decreasing and the vehicle performance can be prevented from decreasing.

  Then, an eccentric member is disposed on one end side in the rotation axis direction, and a cam drive member is disposed on the other end side. The cam drive member includes a sliding portion and a sliding portion of the eccentric member. And a lubricating path for supplying lubricating oil.

  For this reason, in the variable valve drive device that can be mounted without significantly changing the engine configuration and can change the working angle of the cam with a simple configuration, the sliding portion of the member can be efficiently lubricated by the lubrication path.

  In an engine according to an eighth aspect of the present invention, the variable valve driving device having the above-described configuration is mounted with the rotating shaft of the cam driving member parallel to the crankshaft, and the exhaust or intake valve is opened and closed by driving the cam piece. The structure to be taken is taken. According to this configuration, the engine has the same effect as the variable valve driving device configured as described above.

  The motorcycle according to the ninth aspect of the present invention employs a configuration in which the engine having the above-described configuration is mounted with the crankshaft disposed in the vehicle width direction.

  According to this configuration, since the engine including the variable valve driving device in which the eccentric member is not disposed between the cam driving member and the cam piece is mounted with the crankshaft disposed in the vehicle width direction, The crankshaft width does not increase. Specifically, when an eccentric member is provided between the cam drive member and the cam piece, the drive force transmission line from the crankshaft to the cam drive member is accordingly separated from the cylinder axis on which the cam piece is arranged. become. As a result, even when transmission means for transmitting the driving force from the crankshaft to the axle is provided outside the driving force transmission line, the transmission means does not protrude outward and the width of the engine itself does not increase. The bank angle can be prevented from decreasing and the vehicle performance can be prevented from decreasing.

  Further, in the variable valve driving device provided in the motorcycle, the eccentric member is arranged on one end side in the rotation axis direction, and the cam piece slides through the rotation shaft of the cam driving member in which the cam piece is arranged on the other end side. Lubricating passages for supplying lubricating oil to the portion and the sliding portion of the eccentric member are provided. For this reason, in the variable valve drive device that can be mounted without significantly changing the engine configuration and can change the working angle of the cam with a simple configuration, the sliding portion of the member can be efficiently lubricated by the lubrication path.

  The lubricating oil passage of the variable valve driving device according to the present invention is applied to a variable valve driving device, an engine, and a motorcycle that can change the working angle of the cam with a simple configuration without significantly changing the engine configuration. It is useful as a lubricant for lubricating oil parallel and efficiently on each of the sliding portions of the piece and the eccentric member.

The principal part disassembled perspective view of the engine provided with the lubricating oil path of the variable valve drive device which concerns on one embodiment of this invention. Cross-sectional view of the main part showing the variable valve driving device Exploded perspective view of the variable valve drive device A diagram showing the positional relationship between the rotation center of the eccentric boss, the axis of the variable cam drive shaft, and the axis of the eccentric plate Disassembled perspective view of eccentric boss The figure which shows an example of the positional relationship of the drive pin and driven pin of the state which made the center of the eccentric plate eccentric with respect to the cam shaft in the variable valve drive device which concerns on one embodiment of this invention. The figure which shows an example of the valve lift by the variable valve drive device which concerns on this Embodiment The figure which shows the flow of the lubricating oil in the lubricating oil path of the variable valve drive device which concerns on one embodiment of this invention. 1 is a schematic cross-sectional side view showing a main part configuration of a motorcycle including a valve drive device for an engine according to an embodiment of the present invention. FIG. 9 is a schematic plan view showing the main part of the drive unit of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Engine 102 Piston 104 Cylinder head 105 Head cover 106 Cylinder part 110 Engine main body part 130 Crankshaft 133 Cam drive chain 134 Timing gear 200 Variable valve drive device 210 Cam drive body 211 Cam sprocket (cam drive member)
215 Insertion hole 220 Exhaust cam piece 230 Variable cam shaft (cam shaft)
230a Shaft portion 238 Lubrication path 240 Intake cam piece 250 Eccentric plate (eccentric member)
258 Plate shaft part 260 Eccentric boss (member moving part)
267 Compartment (hollow part)
290 Lubricating oil passage 500 Two-wheeled vehicle D2 Valve overlap

Claims (9)

A cam drive member that is rotationally driven by a driving force transmitted from the crankshaft;
The cam drive member is disposed adjacent to one end side of the rotation shaft, and is driven to rotate about an axis in the same direction as the rotation shaft of the cam drive member by driving the cam drive member. An eccentric member provided to be movable from an axial position to an eccentric position;
The rotational phase difference with respect to the cam drive member is a period when the eccentric member is rotationally driven about the rotational shaft by the eccentric member and is rotationally driven at the eccentric position. Fluctuating camshaft,
Lubricating a variable valve driving device that is arranged on the other end side of the rotating shaft of the cam driving member, and is driven to rotate at the same rotational phase as the cam shaft by the cam shaft and drives an exhaust or intake valve. An oil passage,
Provided through the rotation shaft of the cam drive member, supplies lubricating oil to the sliding portion of the cam piece on the other end side of the cam drive member, and the eccentric member on one end side of the cam drive member A lubricating oil passage for a variable valve drive device, comprising a lubricating passage for supplying lubricating oil to a sliding portion of the valve.   The lubricating oil path of a variable valve driving device according to claim 1, wherein the lubricating path is supplied with a lubricating oil from a discharge port of an oil supply pump provided on the other end side of the cam driving member.   The lubrication path has a throttle portion that opens to one end of the cam drive member and adjusts the amount of lubricating oil supplied to the sliding portion of the eccentric member from the other end of the cam drive member. The lubricating oil passage of the variable valve driving device according to claim 2, wherein The cam drive member is rotated at the same rotational phase as the cam drive member, and another cam piece disposed at a position adjacent to the cam piece is provided.
The lubrication path is formed through the rotation shaft of the another cam piece,
2. The lubricating oil passage for a variable valve driving device according to claim 1, wherein a branching oil passage is provided which branches from the lubricating passage and supplies lubricating oil to a sliding portion of the another cam piece. The cam shaft is rotatably inserted through the rotation shaft of the cam drive member,
The lubrication path is formed through the shaft center of the cam shaft having a coaxial axis with the rotation shaft, in the cam shaft,
2. A branch passage is formed in the peripheral wall of the cam shaft so as to branch from the main passage inside and supply lubricating oil to an outer surface that slides on the cam drive member. Lubricating oil passage for variable valve drive. A member moving portion is disposed adjacent to the eccentric member on the opposite side of the cam drive member, and moves the shaft of the eccentric member from a coaxial position to an eccentric position with respect to the rotation axis of the cam drive member. ,
2. The lubricating oil passage for a variable valve drive device according to claim 1, wherein a hollow portion communicating in the direction of the rotation axis is provided in the member moving portion. A cam drive member that is rotationally driven by a driving force transmitted from the crankshaft;
The cam drive member is disposed adjacent to one end side of the rotation shaft, and is driven to rotate about an axis in the same direction as the rotation shaft of the cam drive member by driving the cam drive member. An eccentric member provided to be movable from an axial position to an eccentric position;
The rotational phase difference with respect to the cam drive member is a period when the eccentric member is rotationally driven about the rotational shaft by the eccentric member and is rotationally driven at the eccentric position. Fluctuating camshaft,
A cam piece that is disposed on the other end side of the rotation shaft of the cam drive member, is driven to rotate at the same rotation phase as the cam shaft by the cam shaft, and drives an exhaust or intake valve;
The eccentric member on one end side of the cam drive member is disposed through the rotation shaft of the cam drive member, and supplies lubricating oil to the sliding portion of the cam piece on the other end side of the cam drive member. A lubricating path for supplying lubricating oil to the sliding portion of
A variable valve drive device comprising:   8. The engine according to claim 7, wherein a rotation shaft of the cam drive member is mounted in parallel with a crankshaft, and an exhaust or intake valve is opened and closed by driving of the cam piece.   The motorcycle according to claim 8, wherein the crankshaft is mounted in a vehicle width direction.

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