WO2017168618A1 - Lubricant supply structure of internal combustion engine for vehicle - Google Patents

Lubricant supply structure of internal combustion engine for vehicle Download PDF

Info

Publication number
WO2017168618A1
WO2017168618A1 PCT/JP2016/060333 JP2016060333W WO2017168618A1 WO 2017168618 A1 WO2017168618 A1 WO 2017168618A1 JP 2016060333 W JP2016060333 W JP 2016060333W WO 2017168618 A1 WO2017168618 A1 WO 2017168618A1
Authority
WO
WIPO (PCT)
Prior art keywords
camshaft
oil supply
bearing
exhaust
lubricating oil
Prior art date
Application number
PCT/JP2016/060333
Other languages
French (fr)
Japanese (ja)
Inventor
裕樹 永田
広之 杉浦
Original Assignee
本田技研工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 本田技研工業株式会社 filed Critical 本田技研工業株式会社
Priority to PCT/JP2016/060333 priority Critical patent/WO2017168618A1/en
Publication of WO2017168618A1 publication Critical patent/WO2017168618A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M1/00—Pressure lubrication
    • F01M1/06—Lubricating systems characterised by the provision therein of crankshafts or connecting rods with lubricant passageways, e.g. bores
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M9/00—Lubrication means having pertinent characteristics not provided for in, or of interest apart from, groups F01M1/00 - F01M7/00
    • F01M9/10—Lubrication of valve gear or auxiliaries

Definitions

  • a crankcase and an engine body having a cylinder block and a cylinder head sequentially coupled to the crankcase are mounted on a vehicle body frame, and an intake valve and an exhaust valve arranged to be openable and closable on the cylinder head are opened and closed.
  • One end portion of a camshaft constituting a part of the valve operating mechanism to be driven is rotatably supported by a bearing portion provided in the cylinder head, and lubricating oil supplied from the crankcase side to the cylinder head side is
  • the present invention relates to a lubricating oil supply structure for an internal combustion engine for a vehicle guided to a bearing portion.
  • the camshaft of the valve gear is rotatably supported by a bearing portion provided on the cylinder head of the engine body mounted on the vehicle body frame, and lubricating oil supplied from the crankcase side to the cylinder head side is guided to the bearing portion.
  • a lubricating oil supply structure for an internal combustion engine for a vehicle that is adapted to be used is known from Patent Document 1.
  • an oil hole is provided coaxially in a camshaft that is rotatably supported by a bearing portion of a cylinder head, and from the oil hole to a sliding contact portion with the bearing portion.
  • a lead-out oil passage extending radially outward from the shaft hole so as to guide the lubricating oil is provided. That is, the lubricating oil supplied from the crankcase side to the cylinder head side is guided between the oil hole and the camshaft through the lead-out oil passage and between the camshaft and the bearing portion. The path needs to be drilled and the camshaft is expensive.
  • the camshaft is made of an iron-based metal
  • the cylinder head is made of a light metal such as an aluminum alloy
  • the camshaft is often made of a material having higher hardness. For this reason, there is also a problem that the sharpened processing edge formed by the drilling process of the camshaft is slidably contacted with the bearing portion of the cylinder head, so that the bearing portion is easily worn.
  • An object of the present invention is to provide a lubricating oil supply structure for an internal combustion engine for a vehicle that enables efficient lubrication.
  • a crankcase and an engine main body having a cylinder block and a cylinder head sequentially coupled to the crankcase are mounted on a vehicle body frame, and are arranged to be openable and closable on the cylinder head.
  • One end portion of a camshaft constituting a part of a valve operating mechanism that opens and closes an intake valve and an exhaust valve is rotatably supported by a bearing portion provided in the cylinder head, from the crankcase side to the cylinder head side
  • the camshaft has a bearing hole in which one end portion of the camshaft is rotatably fitted. An oil sump that faces the shaft end is formed, and a spiral oil supply groove is formed on the inner periphery of the bearing hole and through the upstream end of the oil sump.
  • the present invention has a second feature that the oil supply groove is formed in a spiral shape so as to advance in the rotation direction of the camshaft toward the downstream end side. To do.
  • the length of the oil supply groove in the direction along the axis of the camshaft is 1 ⁇ 2 or more of the length along the axis of the bearing hole.
  • the third feature is that it is set to.
  • the downstream end of the oil supply groove is closer to the oil reservoir than the end of the bearing hole opposite to the oil reservoir. It is the fourth feature that they are arranged in the above.
  • the present invention provides an intake side cam provided on the camshaft, an intake side rocker arm provided between the intake valves, and an exhaust provided on the camshaft.
  • An exhaust side rocker arm provided between the side cam and the exhaust valve, a contact portion of the intake side cam and the intake side rocker arm, a contact portion of the exhaust side cam and the exhaust side rocker arm, and downstream of the oil supply groove
  • a fifth feature is that the end portion is arranged on the same side with respect to a virtual plane passing through the axis of the camshaft while being orthogonal to the cylinder axis of the engine body.
  • an oil reservoir is formed in the bearing portion provided in the cylinder head having a bearing hole for rotatably fitting one end portion of the camshaft so as to face the shaft end of the camshaft. Since the oil supply groove that leads to the oil reservoir is formed on the inner periphery of the bearing hole, it is possible to simplify the camshaft without the need to process the camshaft to form the lubricating oil passage. By guiding the lubricating oil from the oil reservoir to the oil supply groove, the gap between the camshaft and the bearing portion can be smoothly lubricated. Moreover, since the oil supply groove is formed in a spiral shape, the lubricating oil can be supplied over a wide range in the circumferential direction between the camshaft and the bearing portion, and the camshaft and the bearing portion can be efficiently lubricated.
  • the lubricating oil is smoothly moved from the oil reservoir to the oil supply groove by forming the oil supply groove in a spiral shape so as to advance in the rotation direction of the camshaft toward the downstream end side.
  • the lubricating oil is easily caught in the sliding contact portion between the camshaft and the bearing portion, and the camshaft and the bearing portion can be more efficiently lubricated.
  • the oil supply groove is formed over a half or more of the length of the bearing hole in the direction along the axis of the camshaft, a wide range of sliding contact portions of the camshaft and the bearing portion is obtained. Can be more efficiently lubricated.
  • the lubricating oil when the downstream end of the oil supply groove reaches the end of the bearing hole opposite to the oil reservoir, the lubricating oil is likely to leak from the bearing, Thus, the lubricating oil can be distributed over a wide range of the bearing portion and the sliding contact portion of the camshaft to efficiently lubricate.
  • a pressing force acts on the camshaft from the contact portion of the intake side rocker arm to the intake side cam and the contact portion of the exhaust side rocker arm to the exhaust side cam.
  • the abutting portions of the intake side cam and the intake side rocker arm and the abutting portions of the exhaust side cam and the exhaust side rocker arm are on the same side with respect to a virtual plane passing through the axis of the camshaft while being orthogonal to the cylinder axis.
  • the gap between the inner surface of the bearing hole of the bearing portion and the camshaft is likely to be formed on the side where the bearing portion is disposed, and the downstream end portion of the lubrication groove is located on the same side as the abutting portion.
  • lubrication to the sliding contact portion of the camshaft can be performed smoothly and efficiently.
  • FIG. 1 is a left side view of the motorcycle according to the first embodiment.
  • FIG. 2 is an enlarged view of a main part of FIG.
  • First embodiment) 3 is a cross-sectional view taken along line 3-3 of FIG.
  • First embodiment) 4 is a cross-sectional view taken along line 4-4 of FIG.
  • First embodiment) 5 is a cross-sectional view taken along line 5-5 of FIG.
  • First embodiment) 6 is a cross-sectional view taken along line 6-6 of FIG.
  • First embodiment 7 is a cross-sectional view taken along line 7-7 of FIG.
  • FIG. 8 is a perspective view of the inside of the bearing hole.
  • First embodiment) 9 is a cross-sectional view taken along line 9-9 of FIG.
  • First embodiment) 10 is a cross-sectional view taken along line 10-10 of FIG.
  • FIG. 11 is a perspective view of a cylinder head according to the second embodiment.
  • Valve mechanism 50 ... ⁇ Camshaft 50a ⁇ ⁇ ⁇ Shaft end 122 ⁇ ⁇ ⁇ intake side cam 123 ⁇ ⁇ ⁇ exhaust side cam 124 ⁇ ⁇ ⁇ intake side rocker arm 125 ⁇ ⁇ ⁇ exhaust side rocker arms 126 and 164 ⁇ ⁇ ⁇ bearing 132 ..Abutting portion 133 of intake side cam and intake side rocker arm ... Abutting portion 148 of exhaust side cam and exhaust side rocker arm ... Bearing hole 148a ... End of bearing hole opposite to oil reservoir 150, 177 ...
  • Oil sump 153 Oil supply groove 153a ... Upstream end 153b of oil supply groove ... Downstream end 154 of oil supply groove ... Rotation direction C1 of camshaft ...
  • front and rear, top and bottom, and left and right refer to directions viewed from the occupant who rides the motorcycle.
  • this saddle-ride type vehicle is a scooter type motorcycle, and its body frame F has a front wheel WF.
  • a front fork 11 that supports the front fork 11, a head pipe 13 that supports the steering handle 12 connected to the front fork 11 so as to be steerable, a down frame 14 that extends rearwardly downward from the head pipe 13, and a vehicle width direction.
  • a cross member 15 that extends and is fixed to the rear end of the down frame 14 and a pair of left and right rear frames 16 that are fixed to the left and right sides of the cross member 15 and extend rearward.
  • a bracket 17 is provided at the lower part of the front end of both rear frames 16 in the body frame F.
  • a front portion of the power unit P is supported on the bracket 17 via a link mechanism 18 so as to be swingable up and down, and a rear wheel WR disposed on the right side of the rear portion of the power unit P is pivotally supported on the rear portion of the power unit P.
  • the A rear cushion unit 19 is provided between the rear frame 16 on the left side of the rear frames 16 and the rear portion of the power unit P.
  • a storage box 20 is disposed above the power unit P, a fuel tank 21 is disposed behind the storage box 20, and the storage box 20 and the fuel tank 21 are supported by the rear frame 16.
  • the vehicle body frame F is covered with a vehicle body cover 22 made of synthetic resin.
  • the vehicle body cover 22 covers the head pipe 13 from the front and the front cover 23 so as to cover the front of the driver's feet.
  • a leg shield 24 connected to the front cover 23, a step floor 25 connected to the lower part of the leg shield 24 for placing a rider's feet, and a side cover 26 connected to the step floor 25 and covering the rear part of the vehicle body from both sides are provided.
  • a tandem type riding seat 27 that covers the storage box 20 and the fuel tank 21 so as to be openable and closable from above is provided above.
  • the power unit P includes an OHC-type internal combustion engine E that is a four-cycle forced air-cooled single cylinder disposed in front of the rear wheel WR, and the internal combustion engine E and the rear engine. And a transmission device T provided between the wheels WR.
  • OHC-type internal combustion engine E that is a four-cycle forced air-cooled single cylinder disposed in front of the rear wheel WR, and the internal combustion engine E and the rear engine.
  • a transmission device T provided between the wheels WR.
  • the engine main body 32 of the internal combustion engine E slides on a crankcase 33 that rotatably supports a crankshaft 28 having a rotation axis parallel to the rotation axis of the rear wheel WR, and a piston 29 connected to the crankshaft 28.
  • a cylinder block 34 having a cylinder bore 30 that can be freely fitted and coupled to the crankcase 33 and a combustion chamber 31 that faces the top of the piston 29 are formed between the cylinder block 34 and the cylinder block 34.
  • 34 includes a cylinder head 35 coupled from the opposite side to the crankcase 33 and a head cover 36 coupled to the cylinder head 35 on the opposite side of the cylinder block 34.
  • the crankcase 33 is composed of left and right case halves 33a and 33b that include the axis of the cylinder bore 30, that is, the cylinder axis C1 and are joined by a plane orthogonal to the axis of the crankshaft 28.
  • the cylinder head 35 is formed with an air jacket 37 disposed outside the combustion chamber 31 so as to open to the outside at one end side along the axis of the crankshaft 28 (right end side in this embodiment).
  • the spark plug 38 is attached to the cylinder head 35 so that a part of the air jacket 37 faces the air jacket 37.
  • An intake device 41 including an air cleaner 39 disposed on the left side of the front portion of the rear wheel WR and a throttle body 40 having an upstream end connected to the air cleaner 39 is connected to the upper side wall of the cylinder head 35, and the cylinder
  • An upstream end of an exhaust pipe 43 that constitutes a part of the exhaust device 42 is connected to the lower side surface of the head 35, and the downstream end of the exhaust pipe 43 is an exhaust muffler (not shown) disposed on the right side of the rear wheel WR. ).
  • the cylinder head 35 includes an intake valve 44 that controls intake air from the intake device 41 to the combustion chamber 31, and an exhaust valve 42 from the combustion chamber 31 to the exhaust device 42.
  • An exhaust valve 45 that controls the exhaust is disposed so as to be openable and closable. The intake valve 44 and the exhaust valve 45 are urged by valve springs 46 and 47 in the valve closing direction.
  • a valve operating chamber 48 formed between the cylinder head 35 and the head cover 36 accommodates a valve operating mechanism 49 that opens and closes the intake valve 44 and the exhaust valve 45.
  • the valve operating mechanism 49 includes: A camshaft 50 having an axis parallel to the crankshaft 28 and rotatably supported by the cylinder head 35 is provided.
  • the rotational power of the crankshaft 28 is transmitted to the camshaft 50 via a timing transmission means 51 disposed on the left side of the cylinder bore 30.
  • the timing transmission means 51 is wound around a drive sprocket 52 fixed to the crankshaft 28, a driven sprocket 53 fixed to the left end of the camshaft 50, the drive sprocket 52 and the driven sprocket 53.
  • An endless cam chain 54 is provided on the left side of the cylinder bore 30 on the left case half 33a of the crankcase 33, the cylinder block 34, and the cylinder head 35. Is formed.
  • a cam chain tensioner guide 56 is slidably contacted with a portion of the cam chain 54 that may be slackened by traveling from the driving sprocket 52 toward the driven sprocket 53, and one end of the cam chain tensioner guide 56.
  • the part is rotatably supported by the left case half 33a via a support shaft 57.
  • a tensioner 58 that exerts an urging force that presses the cam chain tensioner guide 56 against the cam chain 54 is attached to the cylinder block 34.
  • a portion of the cam chain 54 that travels from the driven sprocket 53 toward the drive sprocket 52 is in sliding contact with a cam chain guide 59 that guides the travel of the cam chain 54.
  • One end portion is received by a receiving portion 60 that is integrally formed with the left case half 33a and is open to the crankshaft 28 side, and is formed in a substantially V shape.
  • the other end portion of the cam chain guide 59 is the cylinder It is supported between the block 34 and the cylinder head 35.
  • the left case half 33a of the crankcase 33 is connected to a transmission case 61 extending rearward from the left case half 33a so as to be arranged on the left side of the rear wheel WR.
  • the transmission case 61 includes a transmission case main portion 62 that is integrally connected to the left case half 33 a and extends rearward, and a transmission chamber 65 is formed between the transmission case main portion 62 and the transmission case main portion 62.
  • a gear case cover 63 fastened to the transmission case main portion 62 from the left side and a gear cover that is fastened to the right rear portion of the transmission case main portion 62 by forming a reduction gear chamber 66 between the transmission case main portion 62.
  • 64, and the axle 94 of the rear wheel WR is rotatably supported by the rear portion of the transmission case main portion 62 and the gear cover 64.
  • the left end portion of the crankshaft 28 is linked to and connected to the axle 94 of the rear wheel WR via the transmission device T.
  • the transmission device T is a V-belt type continuously variable that is accommodated in the transmission chamber 65.
  • a transmission 67 and a reduction gear 68 provided between the continuously variable transmission 67 and the axle 94 and housed in the reduction gear chamber 66 are configured.
  • the continuously variable transmission 67 has a drive pulley 69 provided at the left end portion of the crankshaft 28 and an axis parallel to the crankshaft 28 and is rotatably supported by the rear portion of the transmission case main portion 62 and the gear cover 64. And a driven pulley 72 mounted on a transmission shaft 70 via a centrifugal clutch 71 and a drive pulley 69 and an endless V-belt 73 wound around the driven pulley 72.
  • the drive pulley 69 includes a plurality of weight rollers 75 that are accommodated in a floating state between the ramp plate 74 fixed to the crankshaft 28 and the drive pulley 69, in accordance with an increase in the rotational speed of the crankshaft 28. As the shaft 28 moves outward in the radial direction, it operates to increase the contact radius to the V-belt 73.
  • the driven pulley 72 operates so that the contact radius of the V-belt 73 with respect to the drive pulley 69 increases, so that the contact radius of the V-belt 73 decreases, and thereby, between the crankshaft 28 and the transmission shaft 70.
  • the continuously variable transmission according to the rotation of the crankshaft 28 is performed.
  • a kick shaft 76 is rotatably supported on the transmission case cover 63 of the transmission case 61, and a kick pedal 77 (see FIGS. 1 and 2) is provided on the outer end of the kick shaft 76. Further, on the inner surface side of the transmission case cover 63, a kick type starter 95 that can transmit the power of the kick shaft 76 according to the depression operation of the kick pedal 77 to the crankshaft 28 between the kick shaft 76 and the crankshaft 28. Is provided.
  • a generator 78 and a cooling fan 79 are connected to the right end of the crankshaft 28.
  • the generator 78 includes a rotor 80 fixed to the right end portion of the crankshaft 28 outside the right case half 33b in the crankcase 33, and the right case half 33b surrounded by the rotor 80.
  • the stator 81 is fixed.
  • the cooling fan 79 includes a plurality of blades 84 protruding from a base 83 fixed to the rotor 80 of the generator 78 by a plurality of bolts 82.
  • the cylinder block 34 and the cylinder head 35 of the engine main body 32 and the cooling fan 59 are covered with a shroud 85, and forced air cooling air discharged from the cooling fan 79 circulates in the shroud 85.
  • the cylinder block 34 and the cylinder head 35 of the engine body 32 are cooled, and a plurality of cooling fins 34 a and 35 a are respectively provided on the outer surfaces of the cylinder block 34 and the cylinder head 35.
  • the shroud 85 includes a fan cover 86 that covers the cooling fan 79, and a shroud main portion 87 that surrounds the cylinder block 34 and the cylinder head 35 and is connected to the fan cover 86.
  • the upper shroud half 88 that covers the cylinder block 34 and the cylinder head 35 from above, and the lower shroud half 89 that covers the cylinder block 34 and the cylinder head 35 from below are formed by the cylinder axis C1 and the crank. They are connected to each other by a connecting portion 90 along a plane including the axis of the shaft 28.
  • the fan cover 86 is provided with a suction cylinder 92 that forms a suction port 91 for sucking air from the outside toward the cooling fan 59, and is provided coaxially with the crankshaft 28.
  • a louver 93 is provided.
  • the reduction gear 68 is provided between the transmission shaft 70 and the axle 94 and is accommodated in the reduction gear chamber 66, and the rotational power of the transmission shaft 70 in the continuously variable transmission 67 is the reduction gear 68. And is transmitted to the axle 94 of the rear wheel WR.
  • an oil pan portion 111 is provided at the lower portion of the crankcase 33, and the lubricating oil stored in the oil pan portion 111 is pumped up and supplied to the lubricated portion of the engine body 32.
  • the oil pump 112 is disposed in the left case half 33 a of the crankcase 33 below the drive sprocket 98 so as to rotate in conjunction with the crankshaft 28.
  • the oil pump 112 includes an outer rotor 115 and an inner rotor that mesh with a left case half 33a of the crankcase 33 and a pump chamber 114 formed between a cover plate 113 fastened to the left case half 33a. 116 is accommodated, and the inner rotor 115 is fixed to a pump shaft 117 that penetrates the cover plate 113 in a liquid-tight and rotatable manner.
  • the pump shaft 117 is connected to the crankshaft 28 via a drive gear 118 fixed to the crankshaft 28 and a driven gear 119 meshed with the drive gear 118 and fixed to the pump shaft 117. Rotational power is transmitted.
  • the drive gear 118 is formed integrally with the drive sprocket 98 in the timing transmission means 52, as shown in FIG.
  • the lid member 120 that fastens the inside of the crankcase 33 and the transmission chamber 65 in a fluid-tight manner is fastened with bolts 121 to the left case half 33a at a portion corresponding to the oil pump 112.
  • the valve operating mechanism 49 includes the camshaft 50, an intake side cam 122 provided on the camshaft 50 and an intake side rocker arm 124 provided between the intake valves 44, An exhaust side cam 123 provided on the camshaft 50 and an exhaust side rocker arm 125 provided between the exhaust valves 45 are provided.
  • the cylinder head 35 is provided with first and second bearing portions 126 and 127 arranged at intervals in a direction along the axis of the camshaft 50, and one end of the camshaft 50 is a first end portion. 1, the other end side of the camshaft 50 passes through the second bearing portion 127, and a ball bearing 128 (see FIG. 5) is interposed between the second bearing portion 127 and the camshaft 50. 3) is interposed.
  • the first and second bearing portions 126 and 127 are supported by both end portions of a rocker shaft 129 that is disposed on the opposite side of the combustion chamber 31 with respect to the camshaft 50 and extends in parallel with the axis C2 of the camshaft 50.
  • a roller 130 that is in rolling contact with the intake side cam 122 is pivotally supported at one end portion of the intake side rocker arm 124 that is swingably supported by the rocker shaft 129, and is swingable by the rocker shaft 129.
  • a roller 131 that is in rolling contact with the exhaust side cam 123 is pivotally supported at one end of the exhaust side rocker arm 125 supported by the exhaust side rocker arm 125.
  • the abutment portion 132 of the intake side cam 122 and the intake side rocker arm 124 that is, the rolling contact portion of the roller 130 of the intake side rocker arm 124 to the intake side cam 122, the exhaust side cam 123, and the exhaust side rocker arm 125.
  • the contact portion 133 of the exhaust side rocker arm 125 that is, the rolling contact portion of the roller 131 to the exhaust side cam 123, is assumed to pass through the axis C2 of the camshaft 50 while being orthogonal to the cylinder axis C1 of the engine body 32. It is arranged on the same side with respect to the plane PL, that is, on the opposite side to the combustion chamber 31 in this embodiment, that is, on the rocker shaft 129 side.
  • a tappet screw 134 that abuts on a stem end 44a of the intake valve 44 is screwed into an end of the intake side rocker arm 124 opposite to the roller 130 so that the advance / retreat position can be adjusted.
  • a tappet screw 135 that abuts on the stem end 45a of the exhaust valve 45 is screwed onto the end opposite to the roller 131 so that the advance / retreat position can be adjusted.
  • a decompression mechanism 137 is attached to the valve operating mechanism 49, and this decompression mechanism 137 has a decompression cam 138 that can be projected and retracted from a base circle portion 123 a of the exhaust side cam 123 at one end, and the camshaft 50.
  • the decompression shaft 139 is rotatably supported at a position deviated from the rotational axis thereof, and the centrifugal weight 140 is provided at the other end of the decompression shaft 139.
  • the centrifugal weight 140 is attached to the cylinder head 35.
  • the stud bolts 141 and 142 are disposed on the right side of the cylinder bore 30, that is, on the opposite side of the cam chain passage 55 via the cylinder axis C1, and among the stud bolts 141 and 142, An annular oil passage 147 that guides lubricating oil from the oil pump 112 to the cylinder head 35 side is formed between the stud bolt 141 disposed above and the cylinder block 34 and the cylinder head 35. .
  • the first bearing portion 126 provided in the cylinder head 35 has a bearing hole 148 in which one end portion of the camshaft 50 is freely fitted, and the camshaft 50. And a bottomed small-diameter hole 149 that is coaxially connected to the bearing hole 148 and is provided with one end portion of the camshaft 50 in the bearing hole 148. As shown in FIG. 4, an oil reservoir 150 is formed in the bearing portion 126 so as to face the shaft end 50 a of the camshaft 50.
  • the cylinder head 35 has a first branch oil passage 151 that passes through one end of the oil sump 150 while obliquely intersecting the oil passage 147 extending along the axis of the stud bolt 141.
  • the other end side opening of the first branch oil passage 151 on the cylinder block 34 side is closed by a plug member 152.
  • a spiral oil supply groove 153 formed through the oil reservoir 150 through the upstream end 153a is formed.
  • a recess 149 a that communicates with the upstream end 153 a of the oil supply groove 153 is formed on the inner peripheral surface of the small diameter hole 149.
  • the oil supply groove 153 is formed in a spiral shape so as to advance in the rotation direction 154 of the camshaft 50 toward the downstream end 153b side. Moreover, the length L1 of the oil supply groove 153 in the direction along the axis of the camshaft 50 is set to 1 ⁇ 2 or more of the length L2 of the bearing hole 148 along the axis, and the oil supply groove 153 is further provided. The downstream end portion 153b of the bearing hole 148 is disposed closer to the oil reservoir 150 than the end portion 148a of the bearing hole 148 opposite to the oil reservoir 150.
  • downstream end 153b of the oil supply groove 153 is in contact with the intake side cam 122 and the intake side rocker arm 124 with respect to a virtual plane PL passing through the axis C2 of the camshaft 50 while being orthogonal to the cylinder axis C1.
  • exhaust cam 123 and the abutment portion 133 of the exhaust rocker arm 125 that is, on the opposite side to the combustion chamber 31 with respect to the virtual plane PL.
  • the concave portion 149a on the inner peripheral surface of the small-diameter hole 149 and the upstream end portion 153a of the oil supply groove 153 are also in contact with the intake side cam 122 and the contact portion 132 of the intake side rocker arm 124 with respect to the virtual plane PL, and
  • the exhaust side cam 123 and the exhaust side rocker arm 125 are disposed on the same side as the contact portion 133, that is, on the opposite side to the combustion chamber 31 with respect to the virtual plane PL.
  • a relay chamber 155 is formed between the cylinder head 35 and the head cover 36 above the oil passage 147, and one end of the relay chamber 155 communicates with the oil passage 147.
  • the other end of the second branch oil passage 156 formed in the head 35 is communicated with the relay chamber 155.
  • an ejection hole 158 that opens toward the contact portion side of the stem end 44 a of the intake valve 44 and the tappet screw 135 of the intake side rocker arm 124, and the relay chamber 155 are disposed in the ejection hole.
  • a communication passage 157 communicating with 158 is formed, and lubricating oil is sprayed from the ejection hole 158 toward the valve operating mechanism 49.
  • One end portion of the camshaft 50 constituting a part of the valve operating mechanism 49 has a bearing hole 148 provided in the first bearing portion 126 provided in the cylinder head 35.
  • An oil sump 150 is formed in the first bearing portion 126 so as to face the shaft end 50a of the camshaft 50.
  • the oil sump 150 is formed on the inner periphery of the bearing hole 148. Since the spiral oil supply groove 153 formed through the upstream end 153a is formed, it is possible to simplify the camshaft 50 without the need to process the camshaft 50 to form the lubricating oil passage.
  • the oil supply groove 153 is formed in a spiral shape, lubricating oil can be supplied in a wide range in the circumferential direction between the camshaft 50 and the first bearing portion 126, and the camshaft 50 and the first bearing portion 126 can be supplied.
  • the gap can be efficiently lubricated.
  • the oil supply groove 153 is formed in a spiral shape so as to proceed in the rotation direction 154 of the camshaft 50 toward the downstream end 153b side, the lubricating oil is smoothly supplied from the oil reservoir 150 to the oil supply groove 153.
  • the rotation of the camshaft 50 makes it easier for the lubricating oil to be caught in the sliding contact portion between the camshaft 50 and the first bearing portion 126, so that the camshaft 50 and the first bearing portion 126 are connected to each other. Can be more efficiently lubricated.
  • the lubricating oil easily leaks from the first bearing 126 to the valve operating chamber 48.
  • the downstream end portion 153b of the oil supply groove 153 is arranged closer to the oil reservoir 150 than the end of the bearing hole 148 opposite to the oil reservoir 150, this is avoided.
  • the lubricating oil can be distributed over a wide range of the sliding portion of the bearing portion 126 and the camshaft 50 to efficiently lubricate.
  • the contact portion 132 of the intake side cam 122 and the intake side rocker arm 124, the contact portion 133 of the exhaust side cam 123 and the exhaust side rocker arm 125, and the downstream end portion 153b of the oil supply groove 153 are connected to the cylinder axis C1 of the engine body 32.
  • the cylinder head 163 of the engine body 162 is provided with first and second bearing portions 164 and 165 arranged separately in the left-right direction.
  • a boss portion 166 through which the stud bolt 141 is inserted is integrally provided at the upper portion of the 164, and a boss portion 167 through which the stud bolt 142 is inserted is integrally provided at the lower portion of the first bearing portion 164.
  • a boss portion 168 through which the stud bolt 143 is inserted is integrally provided at the upper portion of the portion 165, and a boss portion 169 through which the stud bolt 144 is inserted is integrally provided at the lower portion of the second bearing portion 165.
  • the protruding ends of the boss portions 166 to 169 from the cylinder head 163 are formed on the same plane, and a rectangular reinforcing plate 170 is applied to the protruding ends of the boss portions 166 to 169.
  • the cap nuts 171 are screwed into the protruding portions of the stud bolts 141 to 144 from the reinforcing plate 170 so as to abut and engage with the reinforcing plate 170.
  • the first and second bearing portions 164 and 165 are provided with both ends of an intake side rocker shaft (not shown) for supporting an intake side rocker arm (not shown) and an exhaust side rocker shaft (not shown). Both end portions of an exhaust-side rocker shaft (not shown) to be supported are supported, and a first support cylinder portion that fits and supports one end portion of the intake-side rocker shaft on the first bearing portion 164.
  • the second bearing portion 165 includes the intake side
  • a third support cylinder portion 175 for fitting and supporting the other end portion of the rocker shaft and a fourth support cylinder portion 176 for fitting and supporting the other end portion of the exhaust-side rocker shaft are directed toward the first bearing portion 164 side. Projecting together.
  • the intake rocker arm is disposed between the first and third support cylinders 173 and 175, and the exhaust rocker arm is disposed between the second and fourth support cylinders 174 and 176.
  • the first support cylinder 173 is formed longer than the third support cylinder 175, and the fourth support cylinder 176 is formed longer than the second support cylinder 176. Is done.
  • One end portion of the camshaft is supported by the first bearing portion 164 with the same structure as that of the first embodiment, and an oil sump 177 that faces the shaft end of the camshaft is first.
  • the bearing portion 164 is formed.
  • annular oil passage 178 that guides lubricating oil from the crankcase side (not shown) is formed.
  • the first bearing portion 164 is formed so as to contact the reinforcing plate 170 from the boss portion 166 to a portion corresponding to the oil sump 177, and the first boss portion 166 and the first bearing portion 164.
  • An oil groove 179 is formed on the contact surface with the reinforcing plate 170 to allow the oil passage 178 to pass through one end.
  • a communication passage 180 connecting the other end of the oil groove 179 and the oil reservoir 177 is provided in the first bearing portion 164. According to such a structure, lubricating oil is supplied to the oil reservoir 177. Therefore, the oil passage structure can be simplified.
  • an oil groove 181 serving as a lubricant injection hole may be formed on the contact surface of the boss portion 166 with the reinforcing plate 170 so as to communicate with the oil passage 178. It is desirable to inject the lubricating oil toward a desired portion of the valve mechanism such as around the sliding contact portion of the exhaust rocker arm with the camshaft.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)

Abstract

A lubricant supply structure for an internal combustion engine for a vehicle, wherein an oil reservoir (150) is formed facing the shaft end (50a) of a cam shaft (50) within a bearing (126) having a bearing hole (148) in which one end of the cam shaft (50) is rotatably fitted, and a spiral-shaped oil supply groove (153) is formed in the inner periphery of the bearing hole (148), the upstream end of the oil supply groove (153) communicating with the oil reservoir (150), A bearing is thereby provided in the cylinder head for rotatably supporting the one end of the cam shaft that constitutes a part of a valve mechanism, and as well as supplying the lubricant to the bearing thereof, it is possible to effective lubricate the sliding-contact parts of the cam shaft and the bearing while simplifying the cam shaft, without requiring processing of the cam shaft in order to form a lubricant channel.

Description

車両用内燃機関の潤滑油供給構造Lubricating oil supply structure for vehicle internal combustion engine
　本発明は、クランクケースと、そのクランクケースに順次結合されるシリンダブロックおよびシリンダヘッドを有する機関本体が車体フレームに搭載され、前記シリンダヘッドに開閉可能に配設される吸気弁および排気弁を開閉駆動する動弁機構の一部を構成するカムシャフトの一端部が、前記シリンダヘッドに設けられる軸受部で回転自在に支持され、前記クランクケース側から前記シリンダヘッド側に供給される潤滑油が前記軸受部に導かれる車両用内燃機関の潤滑油供給構造に関する。 In the present invention, a crankcase and an engine body having a cylinder block and a cylinder head sequentially coupled to the crankcase are mounted on a vehicle body frame, and an intake valve and an exhaust valve arranged to be openable and closable on the cylinder head are opened and closed. One end portion of a camshaft constituting a part of the valve operating mechanism to be driven is rotatably supported by a bearing portion provided in the cylinder head, and lubricating oil supplied from the crankcase side to the cylinder head side is The present invention relates to a lubricating oil supply structure for an internal combustion engine for a vehicle guided to a bearing portion.
　車体フレームに搭載される機関本体のシリンダヘッドに設けられる軸受部に、動弁装置のカムシャフトが回転自在に支持され、クランクケース側からシリンダヘッド側に供給される潤滑油が前記軸受部に導かれるようにした車両用内燃機関の潤滑油供給構造が、特許文献１で知られている。 The camshaft of the valve gear is rotatably supported by a bearing portion provided on the cylinder head of the engine body mounted on the vehicle body frame, and lubricating oil supplied from the crankcase side to the cylinder head side is guided to the bearing portion. A lubricating oil supply structure for an internal combustion engine for a vehicle that is adapted to be used is known from Patent Document 1.
日本特開２０１４－１８５５８６号公報Japanese Unexamined Patent Publication No. 2014-185586
　ところが上記特許文献１で開示されたものでは、シリンダヘッドの軸受部で回転自在に支持されるカムシャフトに、油孔が同軸に設けられるとともに、前記軸受部との摺接部に前記油孔から潤滑油を導くようにして前記軸孔から半径方向外側に延びる導出油路が設けられている。すなわちクランクケース側からシリンダヘッド側に供給される潤滑油が、前記油孔から前記導出油路を経てカムシャフトおよび軸受部間に導かれる構造となっており、カムシャフトに、油孔および導出油路を穿孔加工する必要があり、カムシャフトが高価なものとなっている。また一般的に、カムシャフトは鉄系金属から成るのに対して、シリンダヘッドはアルミニウム合金等の軽金属から成り、カムシャフトの方が高硬度の材料から成る場合が多い。このためカムシャフトの穿孔加工で形成される鋭利な加工エッジが、シリンダヘッドの軸受部と摺接することで軸受部が摩耗し易いという課題もある。 However, in the one disclosed in Patent Document 1, an oil hole is provided coaxially in a camshaft that is rotatably supported by a bearing portion of a cylinder head, and from the oil hole to a sliding contact portion with the bearing portion. A lead-out oil passage extending radially outward from the shaft hole so as to guide the lubricating oil is provided. That is, the lubricating oil supplied from the crankcase side to the cylinder head side is guided between the oil hole and the camshaft through the lead-out oil passage and between the camshaft and the bearing portion. The path needs to be drilled and the camshaft is expensive. In general, the camshaft is made of an iron-based metal, whereas the cylinder head is made of a light metal such as an aluminum alloy, and the camshaft is often made of a material having higher hardness. For this reason, there is also a problem that the sharpened processing edge formed by the drilling process of the camshaft is slidably contacted with the bearing portion of the cylinder head, so that the bearing portion is easily worn.
　本発明は、かかる事情に鑑みてなされたものであり、潤滑用油路を形成するためのカムシャフトへの加工を不要としてカムシャフトの簡素化を図りつつ、カムシャフトおよび軸受部の摺接部の効率的な潤滑を可能とした車両用内燃機関の潤滑油供給構造を提供することを目的とする。 The present invention has been made in view of such circumstances, and it is not necessary to process the camshaft for forming a lubricating oil passage, and simplifies the camshaft, while sliding the camshaft and the bearing portion. An object of the present invention is to provide a lubricating oil supply structure for an internal combustion engine for a vehicle that enables efficient lubrication.
　上記目的を達成するために、本発明は、クランクケースと、そのクランクケースに順次結合されるシリンダブロックおよびシリンダヘッドを有する機関本体が車体フレームに搭載され、前記シリンダヘッドに開閉可能に配設される吸気弁および排気弁を開閉駆動する動弁機構の一部を構成するカムシャフトの一端部が、前記シリンダヘッドに設けられる軸受部で回転自在に支持され、前記クランクケース側から前記シリンダヘッド側に供給される潤滑油が前記軸受部に導かれる車両用内燃機関の潤滑油供給構造において、前記カムシャフトの一端部を回転自在に嵌合させる軸受孔を有する前記軸受部内に、前記カムシャフトの軸端を臨ませる油溜まりが形成され、前記軸受孔の内周に、前記油溜まりに上流端部を通じさせた螺旋状の給油溝が形成されることを第１の特徴とする。 In order to achieve the above object, according to the present invention, a crankcase and an engine main body having a cylinder block and a cylinder head sequentially coupled to the crankcase are mounted on a vehicle body frame, and are arranged to be openable and closable on the cylinder head. One end portion of a camshaft constituting a part of a valve operating mechanism that opens and closes an intake valve and an exhaust valve is rotatably supported by a bearing portion provided in the cylinder head, from the crankcase side to the cylinder head side In the vehicular internal combustion engine lubricating oil supply structure in which the lubricating oil supplied to the bearing is guided to the bearing portion, the camshaft has a bearing hole in which one end portion of the camshaft is rotatably fitted. An oil sump that faces the shaft end is formed, and a spiral oil supply groove is formed on the inner periphery of the bearing hole and through the upstream end of the oil sump. To be formed to the first feature.
　また本発明は、第１の特徴の構成に加えて、前記給油溝が、その下流端部側に向かうにつれて前記カムシャフトの回転方向に進むようにして螺旋状に形成されることを第２の特徴とする。 Further, in addition to the configuration of the first feature, the present invention has a second feature that the oil supply groove is formed in a spiral shape so as to advance in the rotation direction of the camshaft toward the downstream end side. To do.
　本発明は、第１または第２の特徴の構成に加えて、前記カムシャフトの軸線に沿う方向での前記給油溝の長さが、前記軸受孔の前記軸線に沿う長さの１／２以上に設定されることを第３の特徴とする。 In the present invention, in addition to the configuration of the first or second feature, the length of the oil supply groove in the direction along the axis of the camshaft is ½ or more of the length along the axis of the bearing hole. The third feature is that it is set to.
　本発明は、第１～第３の特徴の構成のいずれかに加えて、前記給油溝の下流側端部が、前記軸受孔の前記油溜まりとは反対側の端部よりも前記油溜まり側に配置されることを第４の特徴とする。 According to the present invention, in addition to any one of the first to third features, the downstream end of the oil supply groove is closer to the oil reservoir than the end of the bearing hole opposite to the oil reservoir. It is the fourth feature that they are arranged in the above.
　さらに本発明は、第１の特徴の構成に加えて、前記動弁機構が、前記カムシャフトに設けられる吸気側カムおよび前記吸気弁間に設けられる吸気側ロッカアームと、前記カムシャフトに設けられる排気側カムおよび前記排気弁間に設けられる排気側ロッカアームとを備え、前記吸気側カムおよび前記吸気側ロッカアームの当接部、前記排気側カムおよび前記排気側ロッカアームの当接部ならびに前記給油溝の下流端部が、前記機関本体のシリンダ軸線に直交しつつ前記カムシャフトの軸線を通る仮想平面に関して同側に配置されることを第５の特徴とする。 In addition to the configuration of the first feature, the present invention provides an intake side cam provided on the camshaft, an intake side rocker arm provided between the intake valves, and an exhaust provided on the camshaft. An exhaust side rocker arm provided between the side cam and the exhaust valve, a contact portion of the intake side cam and the intake side rocker arm, a contact portion of the exhaust side cam and the exhaust side rocker arm, and downstream of the oil supply groove A fifth feature is that the end portion is arranged on the same side with respect to a virtual plane passing through the axis of the camshaft while being orthogonal to the cylinder axis of the engine body.
　本発明の第１の特徴によれば、カムシャフトの一端部を回転自在に嵌合させる軸受孔を有してシリンダヘッドに設けられる軸受部内に、カムシャフトの軸端を臨ませる油溜まりが形成され、軸受孔の内周に油溜まりに通じる給油溝が形成されるので、潤滑用油路を形成するためのカムシャフトへの加工を不要としてカムシャフトの簡素化を図ることが可能となり、しかも油溜まりから給油溝に潤滑油を導くことでカムシャフトおよび軸受部間を円滑に潤滑することができる。しかも給油溝が螺旋状に形成されるので、カムシャフトおよび軸受部間の周方向で広い範囲に潤滑油を供給することができ、カムシャフトおよび軸受部間を効率よく潤滑することができる。 According to the first feature of the present invention, an oil reservoir is formed in the bearing portion provided in the cylinder head having a bearing hole for rotatably fitting one end portion of the camshaft so as to face the shaft end of the camshaft. Since the oil supply groove that leads to the oil reservoir is formed on the inner periphery of the bearing hole, it is possible to simplify the camshaft without the need to process the camshaft to form the lubricating oil passage. By guiding the lubricating oil from the oil reservoir to the oil supply groove, the gap between the camshaft and the bearing portion can be smoothly lubricated. Moreover, since the oil supply groove is formed in a spiral shape, the lubricating oil can be supplied over a wide range in the circumferential direction between the camshaft and the bearing portion, and the camshaft and the bearing portion can be efficiently lubricated.
　また本発明の第２の特徴によれば、給油溝をその下流端部側に向かうにつれてカムシャフトの回転方向に進むようにした螺旋状とすることで、油溜まりから給油溝に潤滑油が円滑に供給されることになり、カムシャフトの回転によってカムシャフトおよび軸受部の摺接部に潤滑油が巻き込まれ易くなって、カムシャフトおよび軸受部間をより効率よく潤滑することができる。 Further, according to the second feature of the present invention, the lubricating oil is smoothly moved from the oil reservoir to the oil supply groove by forming the oil supply groove in a spiral shape so as to advance in the rotation direction of the camshaft toward the downstream end side. As a result of the rotation of the camshaft, the lubricating oil is easily caught in the sliding contact portion between the camshaft and the bearing portion, and the camshaft and the bearing portion can be more efficiently lubricated.
　本発明の第３の特徴によれば、給油溝が、カムシャフトの軸線に沿う方向で軸受孔の長さの１／２以上にわたって形成されるので、カムシャフトおよび軸受部の摺接部の広範囲をより一層効率よく潤滑することができる。 According to the third feature of the present invention, since the oil supply groove is formed over a half or more of the length of the bearing hole in the direction along the axis of the camshaft, a wide range of sliding contact portions of the camshaft and the bearing portion is obtained. Can be more efficiently lubricated.
　本発明の第４の特徴によれば、給油溝の下流側端部が軸受孔の前記油溜まりとは反対側の端部に達していると、潤滑油が軸受部から漏れ易くなるが、それを回避して軸受部およびカムシャフトの摺接部の広範囲に潤滑油を行き届かせて、効率よく潤滑することができる。 According to the fourth aspect of the present invention, when the downstream end of the oil supply groove reaches the end of the bearing hole opposite to the oil reservoir, the lubricating oil is likely to leak from the bearing, Thus, the lubricating oil can be distributed over a wide range of the bearing portion and the sliding contact portion of the camshaft to efficiently lubricate.
　さらに本発明の第５の特徴によれば、カムシャフトに、吸気側カムへの吸気側ロッカアームの当接部、ならびに排気側カムへの排気側ロッカアームの当接部から押圧力が作用するが、吸気側カムおよび吸気側ロッカアームの当接部、排気側カムおよび排気側ロッカアームの当接部がシリンダ軸線に直交しつつカムシャフトの軸線を通る仮想平面に関して同側に在ることで、前記当接部が配置される側では軸受部の軸受孔の内面およびカムシャフト間に隙間が生じ易くなり、前記当接部と同側に給油溝の下流端部が在ることにより、給油溝から軸受部およびカムシャフトの摺接部への給油を円滑にかつ効率よく行なうことができる。 Further, according to the fifth feature of the present invention, a pressing force acts on the camshaft from the contact portion of the intake side rocker arm to the intake side cam and the contact portion of the exhaust side rocker arm to the exhaust side cam. The abutting portions of the intake side cam and the intake side rocker arm and the abutting portions of the exhaust side cam and the exhaust side rocker arm are on the same side with respect to a virtual plane passing through the axis of the camshaft while being orthogonal to the cylinder axis. The gap between the inner surface of the bearing hole of the bearing portion and the camshaft is likely to be formed on the side where the bearing portion is disposed, and the downstream end portion of the lubrication groove is located on the same side as the abutting portion. In addition, lubrication to the sliding contact portion of the camshaft can be performed smoothly and efficiently.
図１は第１の実施の形態の自動二輪車の左側面図である。（第１の実施の形態）FIG. 1 is a left side view of the motorcycle according to the first embodiment. (First embodiment) 図２は図１の要部拡大図である。（第１の実施の形態）FIG. 2 is an enlarged view of a main part of FIG. (First embodiment) 図３は図２の３－３線断面図である。（第１の実施の形態）3 is a cross-sectional view taken along line 3-3 of FIG. (First embodiment) 図４は図３の４－４断面図である。（第１の実施の形態）4 is a cross-sectional view taken along line 4-4 of FIG. (First embodiment) 図５は図４の５－５線断面図である。（第１の実施の形態）5 is a cross-sectional view taken along line 5-5 of FIG. (First embodiment) 図６は図３の６－６線断面図である。（第１の実施の形態）6 is a cross-sectional view taken along line 6-6 of FIG. (First embodiment) 図７は図４の７－７線断面図である。（第１の実施の形態）7 is a cross-sectional view taken along line 7-7 of FIG. (First embodiment) 図８は軸受孔内を見た斜視図である。（第１の実施の形態）FIG. 8 is a perspective view of the inside of the bearing hole. (First embodiment) 図９は図７の９－９線断面図である。（第１の実施の形態）9 is a cross-sectional view taken along line 9-9 of FIG. (First embodiment) 図１０は図４の１０－１０線断面図である。（第１の実施の形態）10 is a cross-sectional view taken along line 10-10 of FIG. (First embodiment) 図１１は第２の実施の形態のシリンダヘッドの斜視図である。（第２の実施の形態）FIG. 11 is a perspective view of a cylinder head according to the second embodiment. (Second Embodiment)
３２，１６２・・・機関本体
３３・・・クランクケース
３４・・・シリンダブロック
３５，１６３・・・シリンダヘッド
４４・・・吸気弁
４５・・・排気弁
４９・・・動弁機構
５０・・・カムシャフト
５０ａ・・・カムシャフトの軸端
１２２・・・吸気側カム
１２３・・・排気側カム
１２４・・・吸気側ロッカアーム
１２５・・・排気側ロッカアーム
１２６，１６４・・・軸受部
１３２・・・吸気側カムおよび吸気側ロッカアームの当接部
１３３・・・排気側カムおよび排気側ロッカアームの当接部
１４８・・・軸受孔
１４８ａ・・・軸受孔の油溜まりとは反対側の端部
１５０，１７７・・・油溜まり
１５３・・・給油溝
１５３ａ・・・給油溝の上流端部
１５３ｂ・・・給油溝の下流端部
１５４・・・カムシャフトの回転方向
Ｃ１・・・シリンダ軸線
Ｃ２・・・カムシャフトの軸線
Ｌ１・・・給油溝の長さ
Ｌ２・・・軸受孔の長さ
ＰＬ・・・仮想平面 32, 162 ... Engine body 33 ... Crankcase 34 ... Cylinder block 35, 163 ... Cylinder head 44 ... Intake valve 45 ... Exhaust valve 49 ... Valve mechanism 50 ... · Camshaft 50a · · · Shaft end 122 · · · intake side cam 123 · · · exhaust side cam 124 · · · intake side rocker arm 125 · · · exhaust side rocker arms 126 and 164 · · · bearing 132 ..Abutting portion 133 of intake side cam and intake side rocker arm ... Abutting portion 148 of exhaust side cam and exhaust side rocker arm ... Bearing hole 148a ... End of bearing hole opposite to oil reservoir 150, 177 ... Oil sump 153 ... Oil supply groove 153a ... Upstream end 153b of oil supply groove ... Downstream end 154 of oil supply groove ... Rotation direction C1 of camshaft ... The length PL · · · virtual plane length L2 · · · bearing hole axis L1 · · · oil groove da axis C2 · · · camshaft
　以下、本発明の実施の形態について、添付の図面を参照しながら説明する。なお以下の説明で前後、上下および左右は、自動二輪車に乗車した乗員から見た方向を言うものとする。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, front and rear, top and bottom, and left and right refer to directions viewed from the occupant who rides the motorcycle.
第１の実施の形態First embodiment
　本発明の第１の実施の形態について図１～図１０を参照しながら説明すると、先ず図１において、この鞍乗り型車両は、スクータ型の自動二輪車であり、その車体フレームＦは、前輪ＷＦを軸支するフロントフォーク１１ならびに該フロントフォーク１１に連結される操向ハンドル１２を操向可能に支承するヘッドパイプ１３と、該ヘッドパイプ１３から後下がりに延びるダウンフレーム１４と、車幅方向に延びてダウンフレーム１４の後端に固着されるクロスメンバ１５と、該クロスメンバ１５の左右両側に前端が固着されて後上がりに延びる左右一対のリヤフレーム１６とを備える。 A first embodiment of the present invention will be described with reference to FIGS. 1 to 10. First, in FIG. 1, this saddle-ride type vehicle is a scooter type motorcycle, and its body frame F has a front wheel WF. A front fork 11 that supports the front fork 11, a head pipe 13 that supports the steering handle 12 connected to the front fork 11 so as to be steerable, a down frame 14 that extends rearwardly downward from the head pipe 13, and a vehicle width direction. A cross member 15 that extends and is fixed to the rear end of the down frame 14 and a pair of left and right rear frames 16 that are fixed to the left and right sides of the cross member 15 and extend rearward.
　車体フレームＦにおける両リヤフレーム１６の前端下部にはブラケット１７が設けられる。このブラケット１７にはパワーユニットＰの前部がリンク機構１８を介して上下に揺動可能に支承されており、該パワーユニットＰの後部右側に配置される後輪ＷＲがパワーユニットＰの後部に軸支される。また前記両リヤフレーム１６のうち左側のリヤフレーム１６およびパワーユニットＰの後部間にはリヤクッションユニット１９が設けられる。 A bracket 17 is provided at the lower part of the front end of both rear frames 16 in the body frame F. A front portion of the power unit P is supported on the bracket 17 via a link mechanism 18 so as to be swingable up and down, and a rear wheel WR disposed on the right side of the rear portion of the power unit P is pivotally supported on the rear portion of the power unit P. The A rear cushion unit 19 is provided between the rear frame 16 on the left side of the rear frames 16 and the rear portion of the power unit P.
　前記パワーユニットＰの上方には収納ボックス２０が配置され、該収納ボックス２０の後方には燃料タンク２１が配置されており、収納ボックス２０および燃料タンク２１は前記リヤフレーム１６で支持される。 A storage box 20 is disposed above the power unit P, a fuel tank 21 is disposed behind the storage box 20, and the storage box 20 and the fuel tank 21 are supported by the rear frame 16.
　車体フレームＦは、合成樹脂製の車体カバー２２で覆われるものであり、この車体カバー２２は、前記ヘッドパイプ１３を前方から覆うフロントカバー２３と、運転者の足の前方を覆うようにして前記フロントカバー２３に連なるレッグシールド２４と、ライダーの足を載せるべくレッグシールド２４の下部に連なるステップフロア２５と、ステップフロア２５に連なって車体後部を両側から覆うサイドカバー２６とを備え、サイドカバー２６上には、収納ボックス２０および燃料タンク２１を上方から開閉可能として覆うタンデム型の乗車用シート２７が設けられる。 The vehicle body frame F is covered with a vehicle body cover 22 made of synthetic resin. The vehicle body cover 22 covers the head pipe 13 from the front and the front cover 23 so as to cover the front of the driver's feet. A leg shield 24 connected to the front cover 23, a step floor 25 connected to the lower part of the leg shield 24 for placing a rider's feet, and a side cover 26 connected to the step floor 25 and covering the rear part of the vehicle body from both sides are provided. A tandem type riding seat 27 that covers the storage box 20 and the fuel tank 21 so as to be openable and closable from above is provided above.
　図２および図３を併せて参照して、パワーユニットＰは、後輪ＷＲの前方に配置される強制空冷式単気筒の４サイクルであるＯＨＣ型の内燃機関Ｅと、該内燃機関Ｅおよび前記後輪ＷＲ間に設けられる伝動装置Ｔとで構成される。 2 and 3 together, the power unit P includes an OHC-type internal combustion engine E that is a four-cycle forced air-cooled single cylinder disposed in front of the rear wheel WR, and the internal combustion engine E and the rear engine. And a transmission device T provided between the wheels WR.
　前記内燃機関Ｅの機関本体３２は、後輪ＷＲの回転軸線と平行な回転軸線を有するクランクシャフト２８を回転自在に支承するクランクケース３３と、前記クランクシャフト２８に連接されるピストン２９を摺動自在に嵌合せしめるシリンダボア３０を有して前記クランクケース３３に結合されるシリンダブロック３４と、前記ピストン２９の頂部を臨ませる燃焼室３１を前記シリンダブロック３４との間に形成して該シリンダブロック３４に前記クランクケース３３と反対側から結合されるシリンダヘッド３５と、シリンダブロック３４と反対側でシリンダヘッド３５に結合されるヘッドカバー３６とで構成され、この機関本体３２の自動二輪車への搭載時に前記シリンダボア３０の軸線すなわちシリンダ軸線Ｃ１は、ほぼ水平となるまでわずかに前上がりに傾斜している。 The engine main body 32 of the internal combustion engine E slides on a crankcase 33 that rotatably supports a crankshaft 28 having a rotation axis parallel to the rotation axis of the rear wheel WR, and a piston 29 connected to the crankshaft 28. A cylinder block 34 having a cylinder bore 30 that can be freely fitted and coupled to the crankcase 33 and a combustion chamber 31 that faces the top of the piston 29 are formed between the cylinder block 34 and the cylinder block 34. 34 includes a cylinder head 35 coupled from the opposite side to the crankcase 33 and a head cover 36 coupled to the cylinder head 35 on the opposite side of the cylinder block 34. When the engine main body 32 is mounted on a motorcycle, The axis of the cylinder bore 30, that is, the cylinder axis C1 is substantially horizontal. It is slightly tilted upward to the front.
　クランクケース３３は、前記シリンダボア３０の軸線すなわちシリンダ軸線Ｃ１を含むとともに前記クランクシャフト２８の軸線に直交する平面で結合される左および右ケース半体３３ａ，３３ｂから成る。 The crankcase 33 is composed of left and right case halves 33a and 33b that include the axis of the cylinder bore 30, that is, the cylinder axis C1 and are joined by a plane orthogonal to the axis of the crankshaft 28.
　シリンダヘッド３５には、前記クランクシャフト２８の軸線に沿う一端側（この実施の形態では右端側）で外部に開放するようにして前記燃焼室３１の外方に配置されるエアジャケット３７が形成され、そのエアジャケット３７に一部を臨ませるようにして点火プラグ３８がシリンダヘッド３５に取付けられる。 The cylinder head 35 is formed with an air jacket 37 disposed outside the combustion chamber 31 so as to open to the outside at one end side along the axis of the crankshaft 28 (right end side in this embodiment). The spark plug 38 is attached to the cylinder head 35 so that a part of the air jacket 37 faces the air jacket 37.
　前記シリンダヘッド３５の上部側壁には、前記後輪ＷＲの前部左側に配置されるエアクリーナ３９と、該エアクリーナ３９に上流端が接続されるスロットルボディ４０とを含む吸気装置４１が接続され、シリンダヘッド３５の下部側面には、排気装置４２の一部を構成する排気管４３の上流端が接続され、この排気管４３の下流端は後輪ＷＲの右側に配置される排気マフラー（図示せず）に接続される。 An intake device 41 including an air cleaner 39 disposed on the left side of the front portion of the rear wheel WR and a throttle body 40 having an upstream end connected to the air cleaner 39 is connected to the upper side wall of the cylinder head 35, and the cylinder An upstream end of an exhaust pipe 43 that constitutes a part of the exhaust device 42 is connected to the lower side surface of the head 35, and the downstream end of the exhaust pipe 43 is an exhaust muffler (not shown) disposed on the right side of the rear wheel WR. ).
　図４および図５を併せて参照して、前記シリンダヘッド３５には、前記吸気装置４１から前記燃焼室３１への吸気を制御する吸気弁４４と、前記燃焼室３１から前記排気装置４２への排気を制御する排気弁４５とが開閉作動可能に配設されており、前記吸気弁４４および前記排気弁４５は、弁ばね４６，４７で閉弁方向に付勢される。 4 and 5, the cylinder head 35 includes an intake valve 44 that controls intake air from the intake device 41 to the combustion chamber 31, and an exhaust valve 42 from the combustion chamber 31 to the exhaust device 42. An exhaust valve 45 that controls the exhaust is disposed so as to be openable and closable. The intake valve 44 and the exhaust valve 45 are urged by valve springs 46 and 47 in the valve closing direction.
　前記シリンダヘッド３５および前記ヘッドカバー３６間に形成される動弁室４８には、前記吸気弁４４および前記排気弁４５を開閉駆動する動弁機構４９が収容されており、この動弁機構４９は、前記クランクシャフト２８と平行な軸線を有して前記シリンダヘッド３５に回転自在に支持されるカムシャフト５０を備える。 A valve operating chamber 48 formed between the cylinder head 35 and the head cover 36 accommodates a valve operating mechanism 49 that opens and closes the intake valve 44 and the exhaust valve 45. The valve operating mechanism 49 includes: A camshaft 50 having an axis parallel to the crankshaft 28 and rotatably supported by the cylinder head 35 is provided.
　図６を参照して、前記カムシャフト５０には、前記クランクシャフト２８の回転動力が、前記シリンダボア３０の左側に配置される調時伝動手段５１を介して伝達される。 Referring to FIG. 6, the rotational power of the crankshaft 28 is transmitted to the camshaft 50 via a timing transmission means 51 disposed on the left side of the cylinder bore 30.
　前記調時伝動手段５１は、前記クランクシャフト２８に固定される駆動スプロケット５２と、前記カムシャフト５０の左端部に固定される被動スプロケット５３と、前記駆動スプロケット５２および前記被動スプロケット５３に巻き掛けられる無端状のカムチェーン５４とを備え、前記シリンダボア３０の左側で前記クランクケース３３の左ケース半体３３ａ、前記シリンダブロック３４および前記シリンダヘッド３５には、前記カムチェーン５４を走行させるカムチェーン通路５５が形成される。 The timing transmission means 51 is wound around a drive sprocket 52 fixed to the crankshaft 28, a driven sprocket 53 fixed to the left end of the camshaft 50, the drive sprocket 52 and the driven sprocket 53. An endless cam chain 54 is provided on the left side of the cylinder bore 30 on the left case half 33a of the crankcase 33, the cylinder block 34, and the cylinder head 35. Is formed.
　前記カムチェーン５４のうち前記駆動スプロケット５２から前記被動スプロケット５３に向けて走行することで弛む可能性がある部分にはカムチェーンテンショナーガイド５６が摺接されており、このカムチェーンテンショナーガイド５６の一端部は支軸５７を介して左ケース半体３３ａに回動可能に支持される。また前記カムチェーンテンショナーガイド５６を前記カムチェーン５４側に押しつける付勢力を発揮するテンショナ５８が前記シリンダブロック３４に取付けられる。前記カムチェーン５４のうち前記被動スプロケット５３から前記駆動スプロケット５２に向けて走行する部分には、前記カムチェーン５４の走行をガイドするカムチェーンガイド５９が摺接されており、このカムチェーンガイド５９の一端部は、左ケース半体３３ａに一体に設けられて前記クランクシャフト２８側に開放した略Ｖ字状に形成される受け部６０で受けられ、前記カムチェーンガイド５９の他端部は前記シリンダブロック３４および前記シリンダヘッド３５間に支持される。 A cam chain tensioner guide 56 is slidably contacted with a portion of the cam chain 54 that may be slackened by traveling from the driving sprocket 52 toward the driven sprocket 53, and one end of the cam chain tensioner guide 56. The part is rotatably supported by the left case half 33a via a support shaft 57. A tensioner 58 that exerts an urging force that presses the cam chain tensioner guide 56 against the cam chain 54 is attached to the cylinder block 34. A portion of the cam chain 54 that travels from the driven sprocket 53 toward the drive sprocket 52 is in sliding contact with a cam chain guide 59 that guides the travel of the cam chain 54. One end portion is received by a receiving portion 60 that is integrally formed with the left case half 33a and is open to the crankshaft 28 side, and is formed in a substantially V shape. The other end portion of the cam chain guide 59 is the cylinder It is supported between the block 34 and the cylinder head 35.
　図３に注目して、前記クランクケース３３の左ケース半体３３ａには、後輪ＷＲの左側方に配置されるようにして前記左ケース半体３３ａから後方に延出される伝動ケース６１が連設される。この伝動ケース６１は、前記左ケース半体３３ａに一体に連設されて後方に延設される伝動ケース主部６２と、該伝動ケース主部６２との間に変速機室６５を形成して前記伝動ケース主部６２に左側から締結される伝動ケースカバー６３と、前記伝動ケース主部６２との間に減速機室６６を形成して前記伝動ケース主部６２の右側後部に締結されるギヤカバー６４とで構成され、後輪ＷＲの車軸９４は、前記伝動ケース主部６２の後部およびギヤカバー６４に回転自在に支承される。 Referring to FIG. 3, the left case half 33a of the crankcase 33 is connected to a transmission case 61 extending rearward from the left case half 33a so as to be arranged on the left side of the rear wheel WR. Established. The transmission case 61 includes a transmission case main portion 62 that is integrally connected to the left case half 33 a and extends rearward, and a transmission chamber 65 is formed between the transmission case main portion 62 and the transmission case main portion 62. A gear case cover 63 fastened to the transmission case main portion 62 from the left side and a gear cover that is fastened to the right rear portion of the transmission case main portion 62 by forming a reduction gear chamber 66 between the transmission case main portion 62. 64, and the axle 94 of the rear wheel WR is rotatably supported by the rear portion of the transmission case main portion 62 and the gear cover 64.
　前記クランクシャフト２８の左端部は、前記伝動装置Ｔを介して後輪ＷＲの車軸９４に連動、連結されており、この伝動装置Ｔは、前記変速機室６５に収容されるＶベルト式無段変速機６７と、該無段変速機６７および車軸９４間に設けられて前記減速機室６６に収容される減速機６８とで構成される。 The left end portion of the crankshaft 28 is linked to and connected to the axle 94 of the rear wheel WR via the transmission device T. The transmission device T is a V-belt type continuously variable that is accommodated in the transmission chamber 65. A transmission 67 and a reduction gear 68 provided between the continuously variable transmission 67 and the axle 94 and housed in the reduction gear chamber 66 are configured.
　前記無段変速機６７は、前記クランクシャフト２８の左端部に設けられるドライブプーリ６９と、クランクシャフト２８と平行な軸線を有して前記伝動ケース主部６２の後部およびギヤカバー６４に回転自在に支承される伝動軸７０に遠心クラッチ７１を介して装着されるドリブンプーリ７２と、ドライブプーリ６９およびドリブンプーリ７２に巻掛けられる無端状のＶベルト７３とを備える従来周知のものである。 The continuously variable transmission 67 has a drive pulley 69 provided at the left end portion of the crankshaft 28 and an axis parallel to the crankshaft 28 and is rotatably supported by the rear portion of the transmission case main portion 62 and the gear cover 64. And a driven pulley 72 mounted on a transmission shaft 70 via a centrifugal clutch 71 and a drive pulley 69 and an endless V-belt 73 wound around the driven pulley 72.
　前記ドライブプーリ６９は、クランクシャフト２８に固着されたランププレート７４と前記ドライブプーリ６９との間に浮動状態で収容される複数のウエイトローラ７５が、クランクシャフト２８の回転数増大に応じて該クランクシャフト２８の半径方向外方に移動するのに応じて、Ｖベルト７３への接触半径を大きくするように作動する。 The drive pulley 69 includes a plurality of weight rollers 75 that are accommodated in a floating state between the ramp plate 74 fixed to the crankshaft 28 and the drive pulley 69, in accordance with an increase in the rotational speed of the crankshaft 28. As the shaft 28 moves outward in the radial direction, it operates to increase the contact radius to the V-belt 73.
　一方、ドリブンプーリ７２は、ドライブプーリ６９へのＶベルト７３の接触半径が大きくなるにつれて、該Ｖベルト７３の接触半径が小さくなるように作動し、それによりクランクシャフト２８および前記伝動軸７０間でのクランクシャフト２８の回転に応じた無段変速が行なわれることになる。 On the other hand, the driven pulley 72 operates so that the contact radius of the V-belt 73 with respect to the drive pulley 69 increases, so that the contact radius of the V-belt 73 decreases, and thereby, between the crankshaft 28 and the transmission shaft 70. The continuously variable transmission according to the rotation of the crankshaft 28 is performed.
　前記伝動ケース６１における伝動ケースカバー６３にはキック軸７６が回転自在に支承されており、該キック軸７６の外端にキックペダル７７（図１および図２参照）が設けられる。また前記伝動ケースカバー６３の内面側で、キック軸７６およびクランクシャフト２８間には、キックペダル７７の踏込み操作に応じたキック軸７６の動力をクランクシャフト２８に伝達可能としたキック式始動装置９５が設けられる。 A kick shaft 76 is rotatably supported on the transmission case cover 63 of the transmission case 61, and a kick pedal 77 (see FIGS. 1 and 2) is provided on the outer end of the kick shaft 76. Further, on the inner surface side of the transmission case cover 63, a kick type starter 95 that can transmit the power of the kick shaft 76 according to the depression operation of the kick pedal 77 to the crankshaft 28 between the kick shaft 76 and the crankshaft 28. Is provided.
　前記クランクシャフト２８の右端部には、発電機７８および冷却ファン７９が連結される。前記発電機７８は、クランクケース３３における右ケース半体３３ｂの外方でクランクシャフト２８の右端部に固定されるロータ８０と、該ロータ８０で囲繞されるようにして前記右ケース半体３３ｂに固定されるステータ８１とで構成される。 A generator 78 and a cooling fan 79 are connected to the right end of the crankshaft 28. The generator 78 includes a rotor 80 fixed to the right end portion of the crankshaft 28 outside the right case half 33b in the crankcase 33, and the right case half 33b surrounded by the rotor 80. The stator 81 is fixed.
　また前記冷却ファン７９は、前記発電機７８のロータ８０に複数のボルト８２によって固定される基部８３に、複数の羽根８４が突設されて成る。 The cooling fan 79 includes a plurality of blades 84 protruding from a base 83 fixed to the rotor 80 of the generator 78 by a plurality of bolts 82.
　前記機関本体３２のうちシリンダブロック３４およびシリンダヘッド３５と、前記冷却ファン５９とは、シュラウド８５で覆われており、冷却ファン７９から吐出される強制空冷用の空気がシュラウド内８５内を流通することによって機関本体３２のシリンダブロック３４およびシリンダヘッド３５が冷却され、シリンダブロック３４およびシリンダヘッド３５の外面には、複数の冷却フィン３４ａ，３５ａがそれぞれ突設される。 The cylinder block 34 and the cylinder head 35 of the engine main body 32 and the cooling fan 59 are covered with a shroud 85, and forced air cooling air discharged from the cooling fan 79 circulates in the shroud 85. As a result, the cylinder block 34 and the cylinder head 35 of the engine body 32 are cooled, and a plurality of cooling fins 34 a and 35 a are respectively provided on the outer surfaces of the cylinder block 34 and the cylinder head 35.
　前記シュラウド８５は、前記冷却ファン７９を覆うファンカバー８６と、前記シリンダブロック３４および前記シリンダヘッド３５を囲繞して前記ファンカバー８６に連設されるシュラウド主部８７とから成り、シュラウド主部８７は、前記シリンダブロック３４および前記シリンダヘッド３５を上方から覆う上部シュラウド半体８８と、前記シリンダブロック３４および前記シリンダヘッド３５を下方から覆う下部シュラウド半体８９とが、前記シリンダ軸線Ｃ１および前記クランクシャフト２８の軸線を含む平面に沿う結合部９０で相互に結合されて成る。 The shroud 85 includes a fan cover 86 that covers the cooling fan 79, and a shroud main portion 87 that surrounds the cylinder block 34 and the cylinder head 35 and is connected to the fan cover 86. The upper shroud half 88 that covers the cylinder block 34 and the cylinder head 35 from above, and the lower shroud half 89 that covers the cylinder block 34 and the cylinder head 35 from below are formed by the cylinder axis C1 and the crank. They are connected to each other by a connecting portion 90 along a plane including the axis of the shaft 28.
　前記ファンカバー８６には、前記冷却ファン５９側に向けて外部から空気を吸引するための吸引口９１を形成する吸引筒９２が、前記クランクシャフト２８と同軸に設けられ、その吸引口９１にはルーバー９３が設けられる。 The fan cover 86 is provided with a suction cylinder 92 that forms a suction port 91 for sucking air from the outside toward the cooling fan 59, and is provided coaxially with the crankshaft 28. A louver 93 is provided.
　前記減速機６８は、前記伝動軸７０および前記車軸９４間に設けられて前記減速機室６６に収納されるものであり、無段変速機６７における前記伝動軸７０の回転動力が前記減速機６８で減速されて後輪ＷＲの車軸９４に伝達される。 The reduction gear 68 is provided between the transmission shaft 70 and the axle 94 and is accommodated in the reduction gear chamber 66, and the rotational power of the transmission shaft 70 in the continuously variable transmission 67 is the reduction gear 68. And is transmitted to the axle 94 of the rear wheel WR.
　図６に注目して、前記クランクケース３３の下部にはオイルパン部１１１が設けられており、このオイルパン部１１１に貯留される潤滑油を汲み上げて機関本体３２の被潤滑部に給油するためのオイルポンプ１１２が、前記クランクシャフト２８に連動して回転するようにして、前記駆動スプロケット９８の下方で前記クランクケース３３の前記左ケース半体３３ａ内に配設される。 Referring to FIG. 6, an oil pan portion 111 is provided at the lower portion of the crankcase 33, and the lubricating oil stored in the oil pan portion 111 is pumped up and supplied to the lubricated portion of the engine body 32. The oil pump 112 is disposed in the left case half 33 a of the crankcase 33 below the drive sprocket 98 so as to rotate in conjunction with the crankshaft 28.
　前記オイルポンプ１１２は、前記クランクケース３３における左ケース半体３３ａならびに該左ケース半体３３ａに締結されるカバー板１１３間に形成されるポンプ室１１４に、相互に噛合するアウターロータ１１５およびインナーロータ１１６が収容されて成り、前記カバー板１１３を液密にかつ回転自在に貫通するポンプ軸１１７に前記インナーロータ１１５が固定される。 The oil pump 112 includes an outer rotor 115 and an inner rotor that mesh with a left case half 33a of the crankcase 33 and a pump chamber 114 formed between a cover plate 113 fastened to the left case half 33a. 116 is accommodated, and the inner rotor 115 is fixed to a pump shaft 117 that penetrates the cover plate 113 in a liquid-tight and rotatable manner.
　前記ポンプ軸１１７には、前記クランクシャフト２８に固定される駆動ギヤ１１８と、該駆動ギヤ１１８に噛合して前記ポンプ軸１１７に固定される被動ギヤ１１９とを介して、前記クランクシャフト２８からの回転動力が伝達される。前記駆動ギヤ１１８は、この実施の形態では、図３で示すように、前記調時伝動手段５２における駆動スプロケット９８と一体に形成される。 The pump shaft 117 is connected to the crankshaft 28 via a drive gear 118 fixed to the crankshaft 28 and a driven gear 119 meshed with the drive gear 118 and fixed to the pump shaft 117. Rotational power is transmitted. In this embodiment, the drive gear 118 is formed integrally with the drive sprocket 98 in the timing transmission means 52, as shown in FIG.
　前記オイルポンプ１１２に対応する部分で前記左ケース半体３３ａには、前記クランクケース３３内および前記変速機室６５間を液密に隔てる蓋部材１２０がボルト１２１で締結される。 The lid member 120 that fastens the inside of the crankcase 33 and the transmission chamber 65 in a fluid-tight manner is fastened with bolts 121 to the left case half 33a at a portion corresponding to the oil pump 112.
　図４および図５に注目して、前記動弁機構４９は、前記カムシャフト５０と、該カムシャフト５０に設けられる吸気側カム１２２および前記吸気弁４４間に設けられる吸気側ロッカアーム１２４と、前記カムシャフト５０に設けられる排気側カム１２３および前記排気弁４５間に設けられる排気側ロッカアーム１２５とを備える。 4 and 5, the valve operating mechanism 49 includes the camshaft 50, an intake side cam 122 provided on the camshaft 50 and an intake side rocker arm 124 provided between the intake valves 44, An exhaust side cam 123 provided on the camshaft 50 and an exhaust side rocker arm 125 provided between the exhaust valves 45 are provided.
　前記シリンダヘッド３５には、前記カムシャフト５０の軸線に沿う方向に間隔をあけて配置される第１および第２の軸受部１２６，１２７が設けられており、前記カムシャフト５０の一端部は第１の軸受部１２６で回転自在に支持され、前記カムシャフト５０の他端側は第２の軸受部１２７を貫通し、第２の軸受部１２７および前記カムシャフト５０間にはボールベアリング１２８（図３参照）が介装される。また第１および第２の軸受部１２６，１２７には、前記カムシャフト５０に関して前記燃焼室３１と反対側に配置されて前記カムシャフト５０の軸線Ｃ２と平行に延びるロッカシャフト１２９の両端部が支持されており、このロッカシャフト１２９で揺動自在に支持される前記吸気側ロッカアーム１２４の一端部には前記吸気側カム１２２に転がり接触するローラ１３０が軸支され、前記ロッカシャフト１２９で揺動自在に支持される前記排気側ロッカアーム１２５の一端部には前記排気側カム１２３に転がり接触するローラ１３１が軸支される。 The cylinder head 35 is provided with first and second bearing portions 126 and 127 arranged at intervals in a direction along the axis of the camshaft 50, and one end of the camshaft 50 is a first end portion. 1, the other end side of the camshaft 50 passes through the second bearing portion 127, and a ball bearing 128 (see FIG. 5) is interposed between the second bearing portion 127 and the camshaft 50. 3) is interposed. The first and second bearing portions 126 and 127 are supported by both end portions of a rocker shaft 129 that is disposed on the opposite side of the combustion chamber 31 with respect to the camshaft 50 and extends in parallel with the axis C2 of the camshaft 50. A roller 130 that is in rolling contact with the intake side cam 122 is pivotally supported at one end portion of the intake side rocker arm 124 that is swingably supported by the rocker shaft 129, and is swingable by the rocker shaft 129. A roller 131 that is in rolling contact with the exhaust side cam 123 is pivotally supported at one end of the exhaust side rocker arm 125 supported by the exhaust side rocker arm 125.
　しかも前記吸気側カム１２２および前記吸気側ロッカアーム１２４の当接部１３２すなわち前記吸気側ロッカアーム１２４のローラ１３０の前記吸気側カム１２２への転がり接触部、ならびに前記排気側カム１２３および前記排気側ロッカアーム１２５の当接部１３３すなわち前記排気側ロッカアーム１２５の前記ローラ１３１の前記排気側カム１２３への転がり接触部は、前記機関本体３２のシリンダ軸線Ｃ１に直交しつつ前記カムシャフト５０の軸線Ｃ２を通る仮想平面ＰＬに関して同側、この実施の形態では前記燃焼室３１と反対側すなわち前記ロッカシャフト１２９側に配置される。 In addition, the abutment portion 132 of the intake side cam 122 and the intake side rocker arm 124, that is, the rolling contact portion of the roller 130 of the intake side rocker arm 124 to the intake side cam 122, the exhaust side cam 123, and the exhaust side rocker arm 125. The contact portion 133 of the exhaust side rocker arm 125, that is, the rolling contact portion of the roller 131 to the exhaust side cam 123, is assumed to pass through the axis C2 of the camshaft 50 while being orthogonal to the cylinder axis C1 of the engine body 32. It is arranged on the same side with respect to the plane PL, that is, on the opposite side to the combustion chamber 31 in this embodiment, that is, on the rocker shaft 129 side.
　また前記吸気側ロッカアーム１２４の前記ローラ１３０とは反対側の端部には、前記吸気弁４４のステムエンド４４ａに当接するタペットねじ１３４が進退位置を調節可能として螺合され、前記排気側ロッカアーム１２５の前記ローラ１３１とは反対側の端部には、前記排気弁４５のステムエンド４５ａに当接するタペットねじ１３５が進退位置を調節可能として螺合される。 A tappet screw 134 that abuts on a stem end 44a of the intake valve 44 is screwed into an end of the intake side rocker arm 124 opposite to the roller 130 so that the advance / retreat position can be adjusted. A tappet screw 135 that abuts on the stem end 45a of the exhaust valve 45 is screwed onto the end opposite to the roller 131 so that the advance / retreat position can be adjusted.
　ところで前記動弁機構４９にはデコンプ機構１３７が付設されており、このデコンプ機構１３７は、前記排気側カム１２３のベース円部１２３ａから出没可能なデコンプカム１３８を一端部に有して前記カムシャフト５０にその回転軸線からずれた位置で回動自在に支持されるデコンプシャフト１３９と、当該デコンプシャフト１３９の他端部に設けられる遠心ウエイト１４０とを備え、前記遠心ウエイト１４０は、前記シリンダヘッド３５に設けられる第２の軸受部１２７と、前記調時伝動手段５１の前記被動スプロケット５３で挟まれる位置に配置され、前記デコンプシャフト１３９の軸方向移動は、前記吸気側カム１２２および前記被動スプロケット５３で規制される。 By the way, a decompression mechanism 137 is attached to the valve operating mechanism 49, and this decompression mechanism 137 has a decompression cam 138 that can be projected and retracted from a base circle portion 123 a of the exhaust side cam 123 at one end, and the camshaft 50. The decompression shaft 139 is rotatably supported at a position deviated from the rotational axis thereof, and the centrifugal weight 140 is provided at the other end of the decompression shaft 139. The centrifugal weight 140 is attached to the cylinder head 35. It is arranged at a position sandwiched between the second bearing portion 127 provided and the driven sprocket 53 of the timing transmission means 51, and the axial movement of the decompression shaft 139 is caused by the intake side cam 122 and the driven sprocket 53. Be regulated.
　図４および図７に注目して、前記シリンダボア３０の周囲には、前記シリンダブロック３４および前記シリンダヘッド３５を前記クランクケース３３に結合するために前記クランクケース３３に植設される４本のスタッドボルト１４１，１４２，１４３，１４４が配置されており、各スタッボルト１４１～１４４の前記シリンダヘッド３５からの突出部には、前記シリンダヘッド３５との間にワッシャ１４６をそれぞれ介在させるナット１４５がそれぞれ螺合される。 4 and 7, around the cylinder bore 30, four studs are installed in the crankcase 33 in order to connect the cylinder block 34 and the cylinder head 35 to the crankcase 33. Bolts 141, 142, 143, and 144 are arranged, and nuts 145 for interposing washers 146 between the respective head bolts 141 to 144 from the cylinder head 35 are respectively screwed. Combined.
　前記スタッドボルト１４１～１４４のうちスタッドボルト１４１，１４２は、前記シリンダボア３０の右側すなわちシリンダ軸線Ｃ１に介して前記カムチェーン通路５５と反対側に配置されており、それらのスタッドボルト１４１，１４２のうち上方に配置されるスタッドボルト１４１と、前記シリンダブロック３４および前記シリンダヘッド３５との間には、前記オイルポンプ１１２からの潤滑油を前記シリンダヘッド３５側に導く環状のオイル通路１４７が形成される。 Among the stud bolts 141 to 144, the stud bolts 141 and 142 are disposed on the right side of the cylinder bore 30, that is, on the opposite side of the cam chain passage 55 via the cylinder axis C1, and among the stud bolts 141 and 142, An annular oil passage 147 that guides lubricating oil from the oil pump 112 to the cylinder head 35 side is formed between the stud bolt 141 disposed above and the cylinder block 34 and the cylinder head 35. .
　図８および図９を併せて参照して、前記シリンダヘッド３５に設けられる第１の軸受部１２６には、前記カムシャフト５０の一端部を自在に嵌合させる軸受孔１４８と、前記カムシャフト５０よりも小径に形成されて前記軸受け孔１４８に同軸に連なる有底の小径孔１４９とが設けられており、この軸受孔１４８に前記カムシャフト５０の一端部が嵌合された状態で第１の軸受部１２６内には、図４で示すように、前記カムシャフト５０の軸端５０ａを臨ませる油溜まり１５０が形成される。 8 and 9 together, the first bearing portion 126 provided in the cylinder head 35 has a bearing hole 148 in which one end portion of the camshaft 50 is freely fitted, and the camshaft 50. And a bottomed small-diameter hole 149 that is coaxially connected to the bearing hole 148 and is provided with one end portion of the camshaft 50 in the bearing hole 148. As shown in FIG. 4, an oil reservoir 150 is formed in the bearing portion 126 so as to face the shaft end 50 a of the camshaft 50.
　図７に示すように、前記シリンダヘッド３５には、前記スタッドボルト１４１の軸線に沿って延びる前記オイル通路１４７と斜めに交差しつつ前記油溜まり１５０に一端部を通じさせる第１分岐油路１５１が形成されており、この第１分岐油路１５１の前記シリンダブロック３４側の他端側開口部は栓部材１５２で閉じられる。これにより前記油溜まり１５０には、前記オイルポンプ１１２からの潤滑油が前記オイル通路１４７および第１分岐油路１５１を介して供給される。 As shown in FIG. 7, the cylinder head 35 has a first branch oil passage 151 that passes through one end of the oil sump 150 while obliquely intersecting the oil passage 147 extending along the axis of the stud bolt 141. The other end side opening of the first branch oil passage 151 on the cylinder block 34 side is closed by a plug member 152. As a result, the oil from the oil pump 112 is supplied to the oil reservoir 150 through the oil passage 147 and the first branch oil passage 151.
　前記軸受孔１４８の内周には、前記油溜まり１５０に上流端部１５３ａを通じさせた螺旋状の給油溝１５３が形成される。前記油溜まり１５０に前記給油溝１５３の上流端部１５３ａを通じさせるために、前記小径孔１４９の内周面には、前記給油溝１５３の上流端部１５３ａに通じる凹部１４９ａが形成される。 In the inner periphery of the bearing hole 148, a spiral oil supply groove 153 formed through the oil reservoir 150 through the upstream end 153a is formed. In order to allow the upstream end 153 a of the oil supply groove 153 to pass through the oil reservoir 150, a recess 149 a that communicates with the upstream end 153 a of the oil supply groove 153 is formed on the inner peripheral surface of the small diameter hole 149.
　また前記給油溝１５３は、その下流端部１５３ｂ側に向かうにつれて前記カムシャフト５０の回転方向１５４に進むような螺旋状に形成される。しかも前記カムシャフト５０の軸線に沿う方向での前記給油溝１５３の長さＬ１は、前記軸受孔１４８の前記軸線に沿う長さＬ２の１／２以上に設定されており、さらに前記給油溝１５３の前記下流側端部１５３ｂが、前記軸受孔１４８の前記油溜まり１５０とは反対側の端部１４８ａよりも前記油溜まり１５０側に配置される。 Further, the oil supply groove 153 is formed in a spiral shape so as to advance in the rotation direction 154 of the camshaft 50 toward the downstream end 153b side. Moreover, the length L1 of the oil supply groove 153 in the direction along the axis of the camshaft 50 is set to ½ or more of the length L2 of the bearing hole 148 along the axis, and the oil supply groove 153 is further provided. The downstream end portion 153b of the bearing hole 148 is disposed closer to the oil reservoir 150 than the end portion 148a of the bearing hole 148 opposite to the oil reservoir 150.
　しかも前記給油溝１５３の下流端部１５３ｂは、前記シリンダ軸線Ｃ１に直交しつつ前記カムシャフト５０の軸線Ｃ２を通る仮想平面ＰＬに関して、前記吸気側カム１２２および前記吸気側ロッカアーム１２４の当接部１３２、ならびに前記排気側カム１２３および前記排気側ロッカアーム１２５の当接部１３３と同側、すなわち前記仮想平面ＰＬに関して前記燃焼室３１と反対側に配置される。なお前記小径孔１４９の内周面の前記凹部１４９ａおよび前記給油溝１５３の上流端部１５３ａについても、前記仮想平面ＰＬに関して、前記吸気側カム１２２および前記吸気側ロッカアーム１２４の当接部１３２、ならびに前記排気側カム１２３および前記排気側ロッカアーム１２５の当接部１３３と同側、すなわち前記仮想平面ＰＬに関して前記燃焼室３１と反対側に配置される。 In addition, the downstream end 153b of the oil supply groove 153 is in contact with the intake side cam 122 and the intake side rocker arm 124 with respect to a virtual plane PL passing through the axis C2 of the camshaft 50 while being orthogonal to the cylinder axis C1. And the exhaust cam 123 and the abutment portion 133 of the exhaust rocker arm 125, that is, on the opposite side to the combustion chamber 31 with respect to the virtual plane PL. The concave portion 149a on the inner peripheral surface of the small-diameter hole 149 and the upstream end portion 153a of the oil supply groove 153 are also in contact with the intake side cam 122 and the contact portion 132 of the intake side rocker arm 124 with respect to the virtual plane PL, and The exhaust side cam 123 and the exhaust side rocker arm 125 are disposed on the same side as the contact portion 133, that is, on the opposite side to the combustion chamber 31 with respect to the virtual plane PL.
　図１０を併せて参照して、前記オイル通路１４７の上方で前記シリンダヘッド３５および前記ヘッドカバー３６間には中継室１５５が形成されており、一端部が前記オイル通路１４７に通じるようにして前記シリンダヘッド３５に形成される第２分岐油路１５６の他端部が前記中継室１５５に連通される。またヘッドカバー３６の上部内面には、前記吸気弁４４のステムエンド４４ａと、吸気側ロッカアーム１２４のタペットねじ１３５との接触部側に向けて開口する噴出孔１５８と、前記中継室１５５を前記噴出孔１５８に通じさせる連通路１５７とが形成されており、前記動弁機構４９に向けて前記噴出孔１５８から潤滑油が噴霧される。 Referring also to FIG. 10, a relay chamber 155 is formed between the cylinder head 35 and the head cover 36 above the oil passage 147, and one end of the relay chamber 155 communicates with the oil passage 147. The other end of the second branch oil passage 156 formed in the head 35 is communicated with the relay chamber 155. Further, on the upper inner surface of the head cover 36, an ejection hole 158 that opens toward the contact portion side of the stem end 44 a of the intake valve 44 and the tappet screw 135 of the intake side rocker arm 124, and the relay chamber 155 are disposed in the ejection hole. A communication passage 157 communicating with 158 is formed, and lubricating oil is sprayed from the ejection hole 158 toward the valve operating mechanism 49.
　次にこの第１の実施の形態の作用について説明すると、動弁機構４９の一部を構成するカムシャフト５０の一端部は、シリンダヘッド３５に設けられる第１の軸受部１２６が有する軸受孔１４８に回転自在に嵌合され、第１の軸受部１２６内には、前記カムシャフト５０の軸端５０ａを臨ませる油溜まり１５０が形成され、前記軸受孔１４８の内周に、前記油溜まり１５０に上流端部１５３ａを通じさせた螺旋状の給油溝１５３が形成されるので、潤滑用油路を形成するためのカムシャフト５０への加工を不要としてカムシャフト５０の簡素化を図ることが可能となり、しかも油溜まり１５０から給油溝１５３に潤滑油を導くことでカムシャフト５０および第１の軸受部１２６間を円滑に潤滑することができる。しかも給油溝１５３が螺旋状に形成されるので、カムシャフト５０および第１の軸受部１２６間の周方向で広い範囲に潤滑油を供給することができ、カムシャフト５０および第１の軸受部１２６間を効率よく潤滑することができる。 Next, the operation of the first embodiment will be described. One end portion of the camshaft 50 constituting a part of the valve operating mechanism 49 has a bearing hole 148 provided in the first bearing portion 126 provided in the cylinder head 35. An oil sump 150 is formed in the first bearing portion 126 so as to face the shaft end 50a of the camshaft 50. The oil sump 150 is formed on the inner periphery of the bearing hole 148. Since the spiral oil supply groove 153 formed through the upstream end 153a is formed, it is possible to simplify the camshaft 50 without the need to process the camshaft 50 to form the lubricating oil passage. Moreover, by guiding the lubricating oil from the oil reservoir 150 to the oil supply groove 153, it is possible to smoothly lubricate between the camshaft 50 and the first bearing portion 126. Moreover, since the oil supply groove 153 is formed in a spiral shape, lubricating oil can be supplied in a wide range in the circumferential direction between the camshaft 50 and the first bearing portion 126, and the camshaft 50 and the first bearing portion 126 can be supplied. The gap can be efficiently lubricated.
　また前記給油溝１５３が、その下流端部１５３ｂ側に向かうにつれて前記カムシャフト５０の回転方向１５４に進むようにして螺旋状に形成されるので、前記油溜まり１５０から給油溝１５３に潤滑油が円滑に供給されることになり、カムシャフト５０の回転によってカムシャフト５０および第１の軸受部１２６の摺接部に潤滑油が巻き込まれ易くなって、カムシャフト５０と、第１の軸受部１２６との間をより効率よく潤滑することができる。 Further, since the oil supply groove 153 is formed in a spiral shape so as to proceed in the rotation direction 154 of the camshaft 50 toward the downstream end 153b side, the lubricating oil is smoothly supplied from the oil reservoir 150 to the oil supply groove 153. As a result, the rotation of the camshaft 50 makes it easier for the lubricating oil to be caught in the sliding contact portion between the camshaft 50 and the first bearing portion 126, so that the camshaft 50 and the first bearing portion 126 are connected to each other. Can be more efficiently lubricated.
　また前記カムシャフト５０の軸線に沿う方向での前記給油溝１５３の長さＬ１が、前記軸受孔１４８の前記軸線に沿う長さＬ２の１／２以上に設定されるので、カムシャフト５０および第１の軸受部１２６の摺接部の広範囲をより一層効率よく潤滑することができる。 In addition, since the length L1 of the oil supply groove 153 in the direction along the axis of the camshaft 50 is set to ½ or more of the length L2 along the axis of the bearing hole 148, the camshaft 50 and the It is possible to more efficiently lubricate the wide range of the sliding contact portion of one bearing portion 126.
　ところで前記給油溝１５３の下流側端部１５３ｂが軸受孔１４８の前記油溜まり１５０とは反対側の端部に達していると、潤滑油が第１の軸受部１２６から動弁室４８に漏れ易くなるが、前記給油溝１５３の下流側端部１５３ｂが、前記軸受孔１４８の前記油溜まり１５０とは反対側の端部よりも前記油溜まり１５０側に配置されるので、それを回避して第１の軸受部１２６およびカムシャフト５０の摺接部の広範囲に潤滑油を行き届かせて、効率よく潤滑することができる。 By the way, if the downstream end 153 b of the oil supply groove 153 reaches the end of the bearing hole 148 opposite to the oil reservoir 150, the lubricating oil easily leaks from the first bearing 126 to the valve operating chamber 48. However, since the downstream end portion 153b of the oil supply groove 153 is arranged closer to the oil reservoir 150 than the end of the bearing hole 148 opposite to the oil reservoir 150, this is avoided. The lubricating oil can be distributed over a wide range of the sliding portion of the bearing portion 126 and the camshaft 50 to efficiently lubricate.
　さらに吸気側カム１２２および吸気側ロッカアーム１２４の当接部１３２、排気側カム１２３および排気側ロッカアーム１２５の当接部１３３ならびに前記給油溝１５３の下流端部１５３ｂが、機関本体３２のシリンダ軸線Ｃ１に直交しつつカムシャフト５０の軸線Ｃ２を通る仮想平面ＰＬに関して同側に配置されるので、前記当接部１３２，１３３が配置される側では第１の軸受部１２６の軸受孔１４８の内面およびカムシャフト５０間に隙間が生じ易くなり、前記当接部１３２，１３３と同側に給油溝１５３の下流端部１５３ｂが在ることにより、給油溝１５３から第１の軸受部１２６およびカムシャフト５０の摺接部への給油を円滑にかつ効率よく行なうことができる。 Further, the contact portion 132 of the intake side cam 122 and the intake side rocker arm 124, the contact portion 133 of the exhaust side cam 123 and the exhaust side rocker arm 125, and the downstream end portion 153b of the oil supply groove 153 are connected to the cylinder axis C1 of the engine body 32. Since they are arranged on the same side with respect to the virtual plane PL passing through the axis C2 of the camshaft 50 while being orthogonal to each other, on the side where the abutting portions 132 and 133 are arranged, the inner surface of the bearing hole 148 of the first bearing portion 126 and the cam A gap is easily generated between the shafts 50, and the downstream end portion 153 b of the oil supply groove 153 is present on the same side as the contact portions 132 and 133, so that the first bearing portion 126 and the camshaft 50 are connected from the oil supply groove 153. Oil supply to the sliding contact portion can be performed smoothly and efficiently.
第２の実施の形態Second embodiment
　本発明の第２の実施の形態について図１１を参照しながら説明するが、上記第１の実施の形態に対応する部分には同一の参照符号を付して図示するのみとし、詳細な説明は省略する。 The second embodiment of the present invention will be described with reference to FIG. 11, but the parts corresponding to the first embodiment are only given the same reference numerals and shown in detail. Omitted.
　機関本体１６２のシリンダヘッド１６３には、第１の実施の形態と同様に、左右方向に分かれて配置される第１および第２の軸受部１６４，１６５が設けられており、第１の軸受部１６４の上部にはスタッドボルト１４１を挿通させるボス部１６６が一体に設けられ、第１の軸受部１６４の下部にはスタッドボルト１４２を挿通させるボス部１６７が一体に設けられ、また第２の軸受部１６５の上部にはスタッドボルト１４３を挿通させるボス部１６８が一体に設けられ、第２の軸受部１６５の下部にはスタッドボルト１４４を挿通させるボス部１６９が一体に設けられる。 As in the first embodiment, the cylinder head 163 of the engine body 162 is provided with first and second bearing portions 164 and 165 arranged separately in the left-right direction. A boss portion 166 through which the stud bolt 141 is inserted is integrally provided at the upper portion of the 164, and a boss portion 167 through which the stud bolt 142 is inserted is integrally provided at the lower portion of the first bearing portion 164. A boss portion 168 through which the stud bolt 143 is inserted is integrally provided at the upper portion of the portion 165, and a boss portion 169 through which the stud bolt 144 is inserted is integrally provided at the lower portion of the second bearing portion 165.
　前記ボス部１６６～１６９の前記シリンダヘッド１６３からの突出端は同一平面に在るように形成されており、それらのボス部１６６～１６９の前記突出端には、矩形状の補強板１７０が当接されており、前記スタッドボルト１４１～１４４の前記補強板１７０からの突出部には、前記補強板１７０に当接、係合するようにして袋ナット１７１がそれぞれ螺合される。 The protruding ends of the boss portions 166 to 169 from the cylinder head 163 are formed on the same plane, and a rectangular reinforcing plate 170 is applied to the protruding ends of the boss portions 166 to 169. The cap nuts 171 are screwed into the protruding portions of the stud bolts 141 to 144 from the reinforcing plate 170 so as to abut and engage with the reinforcing plate 170.
　第１の軸受部１６４には、図示しないカムシャフトの一端部が回転自在に支持され、第２の軸受部１６５には、前記カムシャフトを回転自在に支持しつつ貫通させるための支持孔１７２が設けられる。また第１および第２の軸受部１６４，１６５には、吸気側ロッカアーム（図示せず）を支持する吸気側ロッカシャフト（図示せず）の両端部と、排気側ロッカシャフト（図示せず）を支持する排気側ロッカシャフト（図示せず）の両端部とが支持されるものであり、第１の軸受部１６４には、前記吸気側ロッカシャフトの一端部を嵌合支持する第１支持筒部１７３と、前記排気側ロッカシャフトの一端部を支持する第２支持筒部１７４とが第２の軸受部１６５側に向けて一体に突設され、第２の軸受部１６５には、前記吸気側ロッカシャフトの他端部を嵌合支持する第３支持筒部１７５と、前記排気側ロッカシャフトの他端部を嵌合支持する第４支持筒部１７６とが第１の軸受部１６４側に向けて一体に突設される。 One end portion of a camshaft (not shown) is rotatably supported by the first bearing portion 164, and a support hole 172 through which the camshaft is rotatably supported is passed through the second bearing portion 165. Provided. The first and second bearing portions 164 and 165 are provided with both ends of an intake side rocker shaft (not shown) for supporting an intake side rocker arm (not shown) and an exhaust side rocker shaft (not shown). Both end portions of an exhaust-side rocker shaft (not shown) to be supported are supported, and a first support cylinder portion that fits and supports one end portion of the intake-side rocker shaft on the first bearing portion 164. 173 and a second support cylinder portion 174 that supports one end portion of the exhaust side rocker shaft are integrally projected toward the second bearing portion 165 side, and the second bearing portion 165 includes the intake side A third support cylinder portion 175 for fitting and supporting the other end portion of the rocker shaft and a fourth support cylinder portion 176 for fitting and supporting the other end portion of the exhaust-side rocker shaft are directed toward the first bearing portion 164 side. Projecting together.
　第１および第３支持筒部１７３，１７５間に前記吸気側ロッカアームが配置され、第２および第４支持筒部１７４，１７６間に前記排気側ロッカアームが配置されるものであり、前記吸気側ロッカアームおよび前記排気側ロッカアームの配置を可能とするために、第１支持筒部１７３が第３支持筒部１７５よりも長く形成され、第４支持筒部１７６が第２支持筒部１７６よりも長く形成される。 The intake rocker arm is disposed between the first and third support cylinders 173 and 175, and the exhaust rocker arm is disposed between the second and fourth support cylinders 174 and 176. In order to allow the exhaust rocker arm to be disposed, the first support cylinder 173 is formed longer than the third support cylinder 175, and the fourth support cylinder 176 is formed longer than the second support cylinder 176. Is done.
　前記カムシャフトの一端部は、第１の軸受部１６４に、前記第１の実施の形態と同様の構造で支持されるものであり、前記カムシャフトの軸端を臨ませる油溜まり１７７が第１の軸受部１６４に形成される。 One end portion of the camshaft is supported by the first bearing portion 164 with the same structure as that of the first embodiment, and an oil sump 177 that faces the shaft end of the camshaft is first. The bearing portion 164 is formed.
　前記スタッドボルト１４１が挿通させる前記ボス部１６６および前記スタッドボルト１４１間には、図示しないクランクケース側からの潤滑油を導く環状のオイル通路１７８が形成される。また第１の軸受部１６４は、前記ボス部１６６から前記油溜まり１７７に対応する部分までは前記補強板１７０に当接するように形成されており、前記ボス部１６６および第１の軸受部１６４の前記補強板１７０への当接面には、前記オイル通路１７８に一端部を通じさせる油溝１７９が形成される。また油溝１７９の他端部および前記油溜まり１７７間を結ぶ連通路１８０が前記第１の軸受部１６４に設けられており、このような構造によれば、油溜まり１７７に潤滑油を供給するための油路構造を簡素化することができる。 Between the boss portion 166 through which the stud bolt 141 is inserted and the stud bolt 141, an annular oil passage 178 that guides lubricating oil from the crankcase side (not shown) is formed. The first bearing portion 164 is formed so as to contact the reinforcing plate 170 from the boss portion 166 to a portion corresponding to the oil sump 177, and the first boss portion 166 and the first bearing portion 164. An oil groove 179 is formed on the contact surface with the reinforcing plate 170 to allow the oil passage 178 to pass through one end. Further, a communication passage 180 connecting the other end of the oil groove 179 and the oil reservoir 177 is provided in the first bearing portion 164. According to such a structure, lubricating oil is supplied to the oil reservoir 177. Therefore, the oil passage structure can be simplified.
　また前記ボス部１６６の前記補強板１７０への当接面に、潤滑油の噴出孔となる油溝１８１を前記オイル通路１７８に通じるようにして形成してもよく、その場合、吸気側ロッカアームおよび排気側ロッカアームのカムシャフトへの摺接部の周囲等の動弁機構の所望部位に指向して潤滑油を噴射するようにすることが望ましい。 In addition, an oil groove 181 serving as a lubricant injection hole may be formed on the contact surface of the boss portion 166 with the reinforcing plate 170 so as to communicate with the oil passage 178. It is desirable to inject the lubricating oil toward a desired portion of the valve mechanism such as around the sliding contact portion of the exhaust rocker arm with the camshaft.
　以上、本発明の実施の形態について説明したが、本発明は上記実施の形態に限定されるものではなく、その要旨を逸脱することなく種々の設計変更を行うことが可能である。 The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the gist of the present invention.

Claims (5)

  1. 　クランクケース（３３）と、そのクランクケース（３３）に順次結合されるシリンダブロック（３４）およびシリンダヘッド（３５，１６３）を有する機関本体（３２，１６２）が車体フレーム（Ｆ）に搭載され、前記シリンダヘッド（３５，１６３）に開閉可能に配設される吸気弁（４４）および排気弁（４５）を開閉駆動する動弁機構（４９）の一部を構成するカムシャフト（５０）の一端部が、前記シリンダヘッド（３５，１６３）に設けられる軸受部（１２６，１６４）で回転自在に支持され、前記クランクケース（３３）側から前記シリンダヘッド（３５，１６３）側に供給される潤滑油が前記軸受部（１２６）に導かれる車両用内燃機関の潤滑油供給構造において、前記カムシャフト（５０）の一端部を回転自在に嵌合させる軸受孔（１４８）を有する前記軸受部（１２６，１６４）内に、前記カムシャフト（５０）の軸端（５０ａ）を臨ませる油溜まり（１５０，１７７）が形成され、前記軸受孔（１４８）の内周に、前記油溜まり（１５０，１７７）に上流端部（１５３ａ）を通じさせた螺旋状の給油溝（１５３）が形成されることを特徴とする車両用内燃機関の潤滑油供給構造。 An engine body (32, 162) having a crankcase (33) and a cylinder block (34) and a cylinder head (35, 163) sequentially coupled to the crankcase (33) is mounted on the vehicle body frame (F), One end of a camshaft (50) that constitutes a part of a valve operating mechanism (49) that opens and closes an intake valve (44) and an exhaust valve (45) disposed in the cylinder head (35, 163) so as to be opened and closed. Are rotatably supported by bearings (126, 164) provided in the cylinder head (35, 163), and are supplied from the crankcase (33) side to the cylinder head (35, 163) side. In a lubricating oil supply structure for an internal combustion engine for a vehicle in which oil is guided to the bearing portion (126), one end portion of the cam shaft (50) is rotatably fitted. An oil sump (150, 177) that faces the shaft end (50a) of the camshaft (50) is formed in the bearing portion (126,164) having the receiving hole (148), and the bearing hole (148). A lubricating oil supply structure for an internal combustion engine for a vehicle, wherein a spiral oil supply groove (153) is formed in the inner periphery of the oil reservoir (150, 177) through an upstream end (153a).
  2. 　前記給油溝（１５３）が、その下流端部（１５３ｂ）側に向かうにつれて前記カムシャフト（５０）の回転方向（１５４）に進むようにして螺旋状に形成されることを特徴とする請求項１に記載の車両用内燃機関の潤滑油供給構造。 The said oil supply groove | channel (153) is formed in a spiral shape so that it may advance to the rotation direction (154) of the said camshaft (50) as it goes to the downstream end part (153b) side. Lubricating oil supply structure for an internal combustion engine for vehicles.
  3. 　前記カムシャフト（５０）の軸線に沿う方向での前記給油溝（１５３）の長さ（Ｌ１）が、前記軸受孔（１４８）の前記軸線に沿う長さ（Ｌ２）の１／２以上に設定されることを特徴とする請求項１または２に記載の車両用内燃機関の潤滑油供給構造。 The length (L1) of the oil supply groove (153) in the direction along the axis of the camshaft (50) is set to ½ or more of the length (L2) along the axis of the bearing hole (148). The lubricating oil supply structure for an internal combustion engine for a vehicle according to claim 1 or 2, wherein the lubricating oil supply structure is used.
  4. 　前記給油溝（１５３）の下流側端部（１５３ｂ）が、前記軸受孔（１４８）の前記油溜まり（１５０，１７７）とは反対側の端部（１４８ａ）よりも前記油溜まり（１５０，１７７）側に配置されることを特徴とする請求項１～３のいずれか１項に記載の車両用内燃機関の潤滑油供給構造。 The oil reservoir (150, 177) has a downstream end portion (153b) of the oil supply groove (153) that is more than the end portion (148a) of the bearing hole (148) opposite to the oil reservoir (150, 177). The lubricating oil supply structure for an internal combustion engine for a vehicle according to any one of claims 1 to 3, wherein the lubricating oil supply structure is disposed on the side of the internal combustion engine.
  5. 　前記動弁機構（４９）が、前記カムシャフト（５０）に設けられる吸気側カム（１２２）および前記吸気弁（４４）間に設けられる吸気側ロッカアーム（１２４）と、前記カムシャフト（５０）に設けられる排気側カム（１２３）および前記排気弁（４５）間に設けられる排気側ロッカアーム（１２５）とを備え、前記吸気側カム（１２２）および前記吸気側ロッカアーム（１２４）の当接部（１３２）、前記排気側カム（１２３）および前記排気側ロッカアーム（１２５）の当接部（１３３）ならびに前記給油溝（１５３）の下流端部（１５３ｂ）が、前記機関本体（３２，１６２）のシリンダ軸線（Ｃ１）に直交しつつ前記カムシャフト（５０）の軸線（Ｃ２）を通る仮想平面（ＰＬ）に関して同側に配置されることを特徴とする請求項１に記載の車両用内燃機関の潤滑油供給構造。 The valve mechanism (49) is connected to an intake side cam (122) provided on the camshaft (50) and an intake side rocker arm (124) provided between the intake valve (44) and the camshaft (50). An exhaust side cam (123) provided between the exhaust side valve (45) and an exhaust side rocker arm (125) provided between the exhaust valve (45) and a contact portion (132) between the intake side cam (122) and the intake side rocker arm (124). ), The exhaust cam (123) and the contact portion (133) of the exhaust rocker arm (125) and the downstream end (153b) of the oil supply groove (153) are the cylinders of the engine body (32, 162). It is arranged on the same side with respect to a virtual plane (PL) passing through the axis (C2) of the camshaft (50) while being orthogonal to the axis (C1). Lubricating oil supply structure for a vehicle internal combustion engine according to 1.
PCT/JP2016/060333 2016-03-30 2016-03-30 Lubricant supply structure of internal combustion engine for vehicle WO2017168618A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/060333 WO2017168618A1 (en) 2016-03-30 2016-03-30 Lubricant supply structure of internal combustion engine for vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/060333 WO2017168618A1 (en) 2016-03-30 2016-03-30 Lubricant supply structure of internal combustion engine for vehicle

Publications (1)

Publication Number Publication Date
WO2017168618A1 true WO2017168618A1 (en) 2017-10-05

Family

ID=59963758

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/060333 WO2017168618A1 (en) 2016-03-30 2016-03-30 Lubricant supply structure of internal combustion engine for vehicle

Country Status (1)

Country Link
WO (1) WO2017168618A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57196209U (en) * 1981-06-09 1982-12-13
JPS6328802U (en) * 1986-08-09 1988-02-25
JPH08312321A (en) * 1995-05-16 1996-11-26 Daihatsu Motor Co Ltd Cam shaft gear lubricating device in dohc type internal combustion engine
JP2001263025A (en) * 2000-03-16 2001-09-26 Nissan Motor Co Ltd Coupling device for driving auxiliary machine of internal combustion engine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57196209U (en) * 1981-06-09 1982-12-13
JPS6328802U (en) * 1986-08-09 1988-02-25
JPH08312321A (en) * 1995-05-16 1996-11-26 Daihatsu Motor Co Ltd Cam shaft gear lubricating device in dohc type internal combustion engine
JP2001263025A (en) * 2000-03-16 2001-09-26 Nissan Motor Co Ltd Coupling device for driving auxiliary machine of internal combustion engine

Similar Documents

Publication Publication Date Title
US7398753B2 (en) Engine with built-in continuously variable transmission
US7311623B2 (en) Engine incorporating a V-belt type continuously variable transmission
US6513613B2 (en) Scooter-type motorcycle
JP6056090B2 (en) Lubricating oil supply structure in vehicle internal combustion engine
US7225705B2 (en) Power transmission device and assembling method for a motorcycle
JP2009243288A (en) Power unit
JP4025667B2 (en) Overhead cam type engine
JP2008190424A (en) Decompression device for internal combustion engine
WO2017168618A1 (en) Lubricant supply structure of internal combustion engine for vehicle
JP2008190423A (en) Oil feeding structure of ohc-type internal combustion engine
JP3975144B2 (en) Power unit with 4-cycle single cylinder engine
JP7022219B2 (en) Internal combustion engine
JP7046213B2 (en) Internal combustion engine
JP7447762B2 (en) Lubrication structure of power transmission mechanism
JP4220415B2 (en) engine
WO2017168616A1 (en) Air-cooled internal combustion engine for saddle-type vehicle
JP6870413B2 (en) Internal combustion engine
JP7019831B2 (en) Internal combustion engine
JP6883066B2 (en) Internal combustion engine structure
JP6542828B2 (en) Internal combustion engine
JP4104407B2 (en) 4-cycle engine oiling device
JP4177687B2 (en) Overhead cam type engine
JP2008082311A (en) Lubrication structure of 4-stroke engine for vehicle
JP2011169182A (en) Valve gear for engine
JP6630218B2 (en) Internal combustion engine

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16896838

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 16896838

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP