WO2015137046A1 - Lubrication structure for valve system - Google Patents

Lubrication structure for valve system Download PDF

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Publication number
WO2015137046A1
WO2015137046A1 PCT/JP2015/054093 JP2015054093W WO2015137046A1 WO 2015137046 A1 WO2015137046 A1 WO 2015137046A1 JP 2015054093 W JP2015054093 W JP 2015054093W WO 2015137046 A1 WO2015137046 A1 WO 2015137046A1
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WO
WIPO (PCT)
Prior art keywords
oil
valve
intake
rocker arm
shaft
Prior art date
Application number
PCT/JP2015/054093
Other languages
French (fr)
Japanese (ja)
Inventor
伸夫 西山
Original Assignee
スズキ株式会社
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 スズキ株式会社 filed Critical スズキ株式会社
Priority to CN201580000646.2A priority Critical patent/CN106062326B/en
Publication of WO2015137046A1 publication Critical patent/WO2015137046A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • 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
    • F01M9/103—Lubrication of valve gear or auxiliaries of valve stem and guide
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L2305/00—Valve arrangements comprising rollers
    • 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
    • F01M1/08—Lubricating systems characterised by the provision therein of lubricant jetting means

Definitions

  • the present invention relates to a lubricating structure for a valve operating device provided in an internal combustion engine.
  • a rocker arm type valve operating device that opens and closes each valve provided in the intake port and the exhaust port is widely known.
  • a rocker shaft supported by a cylinder head of an engine a rocker arm supported by the rocker shaft, a passage formed in the rocker shaft, and a journal portion of the rocker arm are formed.
  • a lubrication structure for a valve operating apparatus including an oil reservoir is disclosed.
  • the oil in the rocker shaft flows into the oil reservoir and is discharged from the oil passage to lubricate the cam that swings the rocker arm.
  • the discharged oil collides with a cam or the like and diffuses, and indirectly lubricates the contact portion between the rocker arm (tappet) and the valve.
  • the lubrication structure of the valve operating apparatus described above sometimes cannot collide and diffuse the discharged oil because the oil discharge pressure also decreases as the engine speed decreases. For example, in the idling state, the oil discharge pressure is a very low value. Therefore, the lubricating structure of the valve operating device described above cannot indirectly supply oil to the contact portion between the tappet and the valve. . Such a problem has become prominent in an engine having a cylinder inclined substantially horizontally. Therefore, the lubrication structure of the valve operating device has problems such as an increase in tappet noise, wear of tappets and valves, and an increase in mechanical loss due to a decrease in lubrication performance.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lubrication structure for a valve operating apparatus capable of maintaining appropriate lubrication performance and improving durability.
  • a lubrication structure for a valve operating apparatus is provided so that a rocker shaft supported by a cylinder head that constitutes a cylinder of an internal combustion engine, and a rocker shaft that is swingably supported by the rocker shaft and abuts on an intake / exhaust valve.
  • an injection portion formed on the fixed boss so as to inject oil in the oil passage toward the contact portion.
  • the injection portion is formed on the fixed boss arranged to face the contact portion between the rocker arm and the valve. Moreover, an injection part injects oil directly toward the applicable contact part. For this reason, compared with the case where oil is collided with an arbitrary member and indirectly diffused, the oil injection (discharge) pressure is sufficient. Therefore, even when the rotational speed of the internal combustion engine is low (for example, during idling), effective oil supply to the corresponding contact portion can be performed. Thereby, tappet sound can be reduced. Further, wear of the rocker arm (tuppet) and the valve can be suppressed, and mechanical loss can be reduced.
  • the shaft further includes a passage in the shaft that is formed inside the rocker shaft and supplies oil to a rocking portion of the rocker arm, and a communication portion that communicates the passage in the shaft and the oil passage, It is preferable that the inner diameter of the injection part is formed larger than the inner diameter of the communication part.
  • the amount of oil injected from the injection unit increases. Thereby, more effective oil supply can be performed to the contact portion between the rocker arm and the valve.
  • the rib prevents the oil injected in large quantities from being diffused wastefully and guides the oil toward the contact portion between the rocker arm and the valve. Thereby, the lubrication efficiency of the valve gear can be improved.
  • valve operating device is preferably installed in the cylinder head provided on a cylinder block extending substantially horizontally from the crankcase, and the rib is disposed above the valve. .
  • the rib is extended from the inner surface of the cylinder head or a head cover covering the cylinder head toward the contact portion.
  • the oil blocked by the rib can be appropriately guided to the contact portion between the rocker arm and the valve.
  • FIG. 1 is a side view showing a motorcycle according to an embodiment of the present invention. It is a side view showing an engine concerning one embodiment of the present invention. It is a side sectional view showing an engine concerning one embodiment of the present invention. 1 is a perspective view showing a cylinder head and a valve operating apparatus of an engine according to an embodiment of the present invention. FIG. 5 is a VV cross-sectional view of FIG. 2. It is a perspective view which shows the cylinder head and valve operating apparatus of the engine which concern on the modification of one Embodiment of this invention.
  • FIG. 1 is a side view showing the motorcycle 1.
  • FIG. 2 is a side view showing the engine 4.
  • FIG. 3 is a side sectional view showing the engine 4.
  • FIG. 4 is a perspective view showing the cylinder head 31 and the valve gear 22.
  • 5 is a cross-sectional view taken along the line VV in FIG. Note that “Fr” indicated by an arrow in each figure indicates the front of the motorcycle 1. Further, in the following description, each direction is set with reference to an occupant who has boarded the motorcycle 1, and the direction is appropriately shown in each figure.
  • a scooter type motorcycle 1 is schematically configured to include a body frame 2, a body cover 3, and an engine 4.
  • the body frame 2 is configured by welding a tube made of steel or aluminum alloy.
  • a pair of left and right front forks 10 are supported at the front portion of the body frame 2 so as to be steerable left and right.
  • a front wheel 11 is rotatably supported at the lower portion of the front fork 10.
  • a handle bar 12 is provided on the upper portion of the front fork 10.
  • a seating seat 13 is provided on the upper rear side of the body frame 2.
  • a storage box 14 is provided below the seating seat 13.
  • the seating sheet 13 is configured to be openable and closable, and serves as a lid for the storage box 14.
  • the body cover 3 includes a front cowl 15, a step board 16, and a seat cowl 17.
  • the front cowl 15 is provided so as to cover the front fork 10 in order to protect the occupant's legs.
  • the step board 16 extends substantially flat from the lower end of the front cowl 15 toward the rear. The occupant seated on the seat 13 places both feet on the step board 16.
  • the seat cowl 17 is provided below the seating seat 13 so as to cover the storage box 14.
  • the engine 4 as an internal combustion engine is, for example, a single-cylinder four-cycle air-cooled engine.
  • the engine 4 is mounted on the vehicle body frame 2 below the storage box 14.
  • the engine 4 includes a crankcase 20, a cylinder 21, and a valve gear 22.
  • the crankcase 20 is connected to be swingable in the vertical direction via a swing pivot P (see FIG. 2) provided at the center lower part of the vehicle body frame 2.
  • a transmission case 23 extends rearward on the left side of the crankcase 20.
  • a power transmission device (not shown) such as a belt type continuously variable transmission is provided inside the transmission case 23.
  • a rear wheel 24 as a drive wheel is rotatably supported at the rear end portion of the transmission case 23 (see FIG. 1). That is, the engine 4 is configured as a so-called unit swing type engine in which the transmission case 23 functions as a swing arm.
  • An air cleaner 25 that filters combustion air is disposed above the transmission case 23 (see FIG. 1).
  • crankshaft 26 extending in the left-right direction is supported in the crankcase 20.
  • the crankshaft 26 is connected to a piston 28 via a connecting rod 27.
  • the crankshaft 26 is connected to the rear wheel 24 via a power transmission device in the transmission case 23.
  • the cylinder 21 includes a cylinder block 30, a cylinder head 31, and a head cover 32.
  • the cylinder block 30 extends substantially horizontally from the front end surface of the crankcase 20. Specifically, the cylinder block 30 is provided in the crankcase 20 so as to be inclined slightly upward toward the front.
  • the cylinder head 31 is provided at the tip (front end) of the cylinder block 30.
  • the head cover 32 is provided so as to cover the front end surface (front end surface) of the cylinder head 31.
  • a combustion chamber 33 is formed between the cylinder block 30 and the cylinder head 31.
  • An intake port 34 is formed on the upper side of the combustion chamber 33.
  • An intake port 35 communicating with the intake port 34 is formed on the upper surface of the cylinder head 31.
  • An air cleaner 25 and a fuel injection device are connected to the intake port 35.
  • an exhaust port 36 is formed below the combustion chamber 33.
  • An exhaust port 37 communicating with the exhaust port 36 is formed on the lower surface of the cylinder head 31.
  • An exhaust muffler (both not shown) is connected to the exhaust port 37 via an exhaust pipe.
  • a cam chain chamber R communicating with the crankcase 20 is formed on the left side of the cylinder block 30 and the cylinder head 31 (see FIG. 4).
  • Fuel and air purified by the air cleaner 25 are mixed and supplied from the intake port 35 to the combustion chamber 33 through the intake port 34.
  • the air-fuel mixture is ignited by a spark plug (not shown) and burns in the combustion chamber 33.
  • the combustion pressure of the mixture pushes the piston 28.
  • the reciprocating piston 28 rotates the crankshaft 26 via the connecting rod 27.
  • the rotational force of the crankshaft 26 rotates the rear wheel 24 via a power transmission device in the transmission case 23.
  • Exhaust gas after combustion is discharged from the exhaust port 36 to the outside through the exhaust port 37 and the exhaust pipe.
  • valve gear 22 is supported by a cam housing 40 provided inside the cylinder head 31.
  • Ball bearings 41 are mounted on the left and right walls of the cam housing 40, respectively.
  • shaft insertion holes 42 and 43 extending in the left-right direction are formed in the upper and lower ends of the cam housing 40, respectively.
  • the cam housing 40 is integrally formed with a plurality of fixed bosses 44 used for assembling the cylinder 21.
  • the fixed boss 44 includes four head fixing bosses 45 and two cover fixing bosses 46.
  • the four head fixing bosses 45 are arranged at both upper and lower ends of the left and right walls of the cam housing 40.
  • the head fixing boss 45 is erected substantially forward from the bottom surface of the cylinder head 31. That is, the four head fixing bosses 45 are arranged in a 2 ⁇ 2 grid pattern in a front view.
  • the head fixing boss 45 has a bolt insertion hole 47 at the center and is formed in a substantially cylindrical shape.
  • stud bolts B1 fixed to the crankcase 20 are loosely inserted into the four bolt insertion holes 47, respectively.
  • the bolt insertion hole 47 is formed so as to penetrate the cylinder block 30 and the cylinder head 31.
  • the cylinder block 30 and the cylinder head 31 are fixed to the crankcase 20 by screwing a nut N into the tip of the penetrating stud bolt B1.
  • the two cover fixing bosses 46 are fixed to the upper right head fixing boss 45 and the lower left head fixing boss 45. More specifically, the upper right cover fixing boss 46 is integrally provided on the upper side of the head fixing boss 45 while being inclined toward the center. The lower left cover fixing boss 46 is provided integrally with the lower side of the head fixing boss 45 so as to be inclined outward (left side).
  • the cover fixing boss 46 has a female thread portion 48 at the center and is formed in a substantially cylindrical shape.
  • the head cover 32 is fixed to the cylinder head 31 by screwing a pair of cover bolts B2 into the female screw portion 48 of the cover fixing boss 46 (see FIG. 2).
  • the valve gear 22 includes an intake valve 50 and an exhaust valve 51, a cam shaft 52, an intake cam 53 and an exhaust cam 54, an intake rocker shaft 55 and an exhaust rocker shaft 56, and an intake rocker arm. 57 and the exhaust rocker arm 58.
  • the valve gear 22 employs a so-called SOHC system.
  • the intake valve 50 and the exhaust valve 51 are inserted through valve guides 60 and 61 fixed to the cylinder head 31, respectively.
  • the intake valve 50 is urged in a direction to close the intake port 34 by an intake side valve spring 62.
  • the exhaust valve 51 is urged in a direction to close the exhaust port 36 by an exhaust side valve spring 63.
  • the camshaft 52 is formed in a substantially hollow cylindrical shape.
  • the camshaft 52 is pivotally supported by a pair of left and right ball bearings 41 (see FIG. 4).
  • an intake cam 53 and an exhaust cam 54 are juxtaposed.
  • the intake cam 53 and the exhaust cam 54 are so-called eccentric cams and are formed in substantially the same shape.
  • the left end portion of the cam shaft 52 extends through the ball bearing 41 to the cam chain chamber R.
  • a cam sprocket 64 is fixed to the left end portion of the camshaft 52.
  • a cam drive sprocket (not shown) is fixed to the left end portion of the crankshaft 26 described above.
  • a cam chain 65 is stretched between the cam sprocket 64 and the cam drive sprocket.
  • the intake rocker shaft 55 and the exhaust rocker shaft 56 are formed in a substantially hollow cylindrical shape.
  • the intake rocker shaft 55 and the exhaust rocker shaft 56 are supported by the cam housing 40 (cylinder head 31). Specifically, the intake rocker shaft 55 is mounted in the upper shaft insertion hole 42.
  • the exhaust rocker shaft 56 is mounted in the lower shaft insertion hole 43.
  • engagement grooves 55 a and 56 a are respectively provided in the left end portions of the intake rocker shaft 55 and the exhaust rocker shaft 56.
  • the restriction plate 66 is locked to the pair of upper and lower engagement grooves 55a and 56a.
  • the restriction plate 66 is installed between the shafts 55 and 56, and is fixed to the cam housing 40 by a plate bolt B3. Thereby, each rocker shaft 55 and 56 is restricted from moving in the left-right direction.
  • the intake rocker arm 57 and the exhaust rocker arm 58 are long in the vertical direction.
  • the intake rocker arm 57 and the exhaust rocker arm 58 are respectively boss portions 57a and 58a formed at the substantially central portion in the longitudinal direction, slipper portions 57b and 58b formed at one end portion, and an arm portion formed at the other end portion. 57c, 58c.
  • the intake rocker arm 57 is swingably supported by an intake rocker shaft 55 inserted through the boss portion 57a.
  • the slipper portion 57 b of the intake rocker arm 57 is in contact with the intake cam 53.
  • An intake tappet 67 is fixed to the arm portion 57 c of the intake rocker arm 57.
  • the intake rocker arm 57 is provided so as to come into contact with the tip of the intake valve 50 via an intake tappet 67.
  • the exhaust rocker arm 58 is swingably supported by an exhaust rocker shaft 56 inserted through the boss portion 58a.
  • the slipper portion 58 b of the exhaust rocker arm 58 is in contact with the exhaust cam 54.
  • An exhaust tappet 68 is fixed to the arm portion 58 c of the exhaust rocker arm 58.
  • the exhaust rocker arm 58 is provided so as to come into contact with the tip of the exhaust valve 51 via the exhaust tappet 68.
  • valve gear 22 will be described with reference to FIG.
  • Rotational force of the engine 4 rotates the camshaft 52 via the cam chain 65.
  • the cams 53 and 54 that rotate together with the camshaft 52 repeatedly press and release the slipper portions 57b and 58b of the rocker arms 57 and 58, respectively.
  • the rocker arms 57 and 58 swing around the rocker shafts 55 and 56, respectively.
  • the swinging intake rocker arm 57 repeats pressing and releasing of the intake valve 50 via the intake tappet 67.
  • the swinging exhaust rocker arm 58 repeatedly presses and releases the exhaust valve 51 via the exhaust tappet 68.
  • the valves 50 and 51 reciprocate in the axial direction to open and close the intake port 34 and the exhaust port 36. As a result, intake and exhaust of the combustion chamber 33 is performed.
  • the valve operating device 22 described above has a structure for supplying oil for cooling and lubrication to the movable part (hereinafter referred to as “lubricating structure 70”).
  • lubricating structure 70 a structure for supplying oil for cooling and lubrication to the movable part.
  • the lubricating structure 70 of the valve gear 22 will be described.
  • the lubrication structure 70 includes an oil passage 71 formed in the upper right fixed boss 44, an in-shaft passage 72 formed in the intake rocker shaft 55, and the upper right fixed boss 44. And an injection port 75 as an injection portion to be formed.
  • the upper right head fixing boss 45 is referred to as a “first fixing boss 45A”
  • the upper right cover fixing boss 46 is referred to as a “second fixing boss 46A”.
  • the oil passage 71 has a first oil passage 71a and a second oil passage 71b.
  • the first oil passage 71a is constituted by a gap between the bolt insertion hole 47 of the first fixed boss 45A and the stud bolt B1 penetrating therethrough.
  • the second oil passage 71b extends from the first oil passage 71a to the inside of the second fixed boss 46A.
  • an injection oil storage portion 76 is formed between the tip end portion of the cover bolt B2 and the bottom portion of the second fixing boss 46A.
  • a substantially circular communication hole 80 as a communication portion is opened on the lower inner surface of the first oil passage 71a.
  • the communication hole 80 is countersunk from the inside (the first oil passage 71a side).
  • the communication hole 80 is formed so as to connect the in-shaft passage 72 and the first oil passage 71a.
  • the in-shaft passage 72 extends in the axial direction of the intake rocker shaft 55.
  • An in-shaft communication hole 81 is formed in the inner surface of the in-shaft passage 72 at a position corresponding to the swinging portion (sliding portion) of the intake rocker arm 57.
  • the boss portion 57 a of the intake rocker arm 57 is provided with an intake side oil reservoir 82 at a swinging portion with the intake rocker shaft 55.
  • the in-shaft communication hole 81 is formed so as to allow the in-shaft passage 72 and the intake-side oil reservoir 82 to communicate with each other. That is, the in-shaft passage 72 is configured to supply oil to the swinging portion of the intake rocker arm 57.
  • An intake side opening 83 communicating with the intake side oil reservoir 82 is formed in the boss portion 57 a of the intake rocker arm 57.
  • the intake side opening 83 is provided toward a contact portion between the intake cam 53 and the slipper portion 57 b of the intake rocker arm 57.
  • the first fixed boss 45A and the second fixed boss 46A are provided to face the intake rocker arm 57 from the outside (right side).
  • the first fixed boss 45 ⁇ / b> A is disposed to face a portion between the boss portion 57 a and the arm portion 57 c of the intake rocker arm 57.
  • the second fixed boss 46 ⁇ / b> A is disposed to face the contact portion 90 between the intake tappet 67 of the intake rocker arm 57 and the intake valve 50.
  • the injection port 75 is configured to inject the oil in the oil passage 71 toward a contact portion 90 between the intake tappet 67 and the intake valve 50 (hereinafter also simply referred to as “contact portion 90”). 46A.
  • the injection port 75 is a substantially circular opening, and is formed in the side wall of the second fixed boss 46A. Specifically, the injection port 75 is formed on the oblique left side surface of the second fixed boss 46A in front view. Moreover, the injection port 75 is located on the substantially same plane as the contact part 90 (refer FIG. 4).
  • the inner diameter of the injection port 75 is formed larger than the inner diameter of the communication hole 80.
  • -Oil for cooling and lubrication is pumped by an oil pump (not shown).
  • the pumped oil is supplied to the first oil passage 71a.
  • the oil pump is driven by the rotation of the crankshaft 26.
  • the oil supplied to the first oil passage 71a is guided to the in-shaft passage 72 through the communication hole 80.
  • the oil supplied to the in-shaft passage 72 is guided to the intake side oil reservoir 82 through the in-shaft communication hole 81.
  • the oil in the intake side oil reservoir 82 lubricates the boss portion 57 a of the intake rocker arm 57.
  • the oil in the intake side oil reservoir 82 is discharged from the intake side opening 83 toward the contact portion between the intake cam 53 and the slipper portion 57 b of the intake rocker arm 57. Since the cylinder 21 is provided substantially horizontally, the oil discharged from the intake side opening 83 is diffused while dropping from the intake rocker shaft 55 located above to the exhaust rocker shaft 56 located below. . For this reason, the oil discharged from the intake side opening 83 lubricates each ball bearing 41, the intake cam 53, the exhaust cam 54, the slipper portion 57b, and the slipper portion 58b.
  • the oil supply pressure by the oil pump changes substantially in proportion to the increase / decrease in the rotational speed of the engine 4 (crankshaft 26). That is, the higher the rotational speed of the engine 4, the higher the pressure of the oil pump, and the lower the rotational speed of the engine 4, the lower the pressure of the oil pump.
  • the pressure of the oil pump becomes sufficiently high, so that a sufficient amount of oil flows out from the intake side opening 83 and the like.
  • the oil that has flowed out is scattered (diffused) by the rotation of the cams 53 and 54 and the swinging of the rocker arms 57 and 58. For this reason, the scattered oil is also supplied to the contact portion 90 between each valve 50, 51 and each tappet 67, 68 to lubricate the contact portion 90.
  • the lubrication structure 70 of the valve gear 22 is configured to inject oil from the injection port 75 and lubricate the contact portion 90.
  • the oil supplied to the first oil passage 71a is guided to the injection oil reservoir 76 of the second fixed boss 46A through the second oil passage 71b.
  • the oil in the injection oil reservoir 76 is injected from the injection port 75 by the oil supply pressure by the oil pump.
  • the injection port 75 injects oil toward the upper left.
  • the oil injected from the injection port 75 draws a parabola (see the dotted line shown in FIG. 4) and adheres to the contact portion 90 between the intake valve 50 and the intake tappet 67 and lubricates the contact portion 90.
  • the oil injected from the injection port 75 diffuses while dropping and lubricates the contact portion between the exhaust valve 51 and the exhaust tappet 68.
  • the injection port 75 is disposed to face the contact portion 90 between the intake rocker arm 57 (intake tappet 67) and the intake valve 50.
  • Two fixed bosses 46A are formed.
  • the injection port 75 directly injects oil toward the abutting portion 90. For this reason, compared with the case where oil is collided with an arbitrary member and indirectly diffused, the oil injection (discharge) pressure is sufficient. Therefore, even when the rotational speed of the engine 4 is low (for example, during idling), effective oil supply to the contact portion 90 can be performed. Thereby, tappet sound can be reduced. Further, wear of the intake rocker arm 57 (intake tappet 67) and the intake valve 50 can be suppressed, and mechanical loss can be reduced.
  • the injection amount of oil from the injection port 75 is increased by making the injection port 75 larger in diameter than the communication hole 80. Accordingly, more effective oil supply can be performed to the contact portion 90 between the intake rocker arm 57 (intake tappet 67) and the intake valve 50.
  • FIG. 6 is a perspective view showing the cylinder head 31 and the valve gear 22.
  • symbol is attached
  • the lubrication structure 70 of the valve gear 22 according to the present modification further includes a rib 100 that blocks oil injected from the injection port 75 and reflects the oil toward the contact portion 90 between the intake tappet 67 and the intake valve 50. .
  • the rib 100 is formed in a rectangular plate shape.
  • the rib 100 is disposed above the intake valve 50.
  • the rib 100 extends from the upper inner surface of the cylinder head 31 toward the contact portion 90.
  • the rib 100 is provided so as to hang from the upper inner surface of the cylinder head 31 at a position closer to the cam chain chamber R than the intake valve 50.
  • the leading end (lower end) of the rib 100 is located near the upper portion of the contact portion 90.
  • the rib 100 may be provided on the upper inner surface of the head cover 32 that covers the cylinder head 31.
  • the rib 100 prevents the oil injected in large quantities from being diffused wastefully, and the intake rocker arm 57 (intake air). Oil is guided toward the contact portion 90 between the tappet 67) and the intake valve 50 (see the dotted line shown in FIG. 6). Thereby, the lubrication efficiency of the valve gear 22 can be improved.
  • the lubrication structure 70 of the valve gear 22 since the tip of the rib 100 is located in the vicinity of the upper portion of the contact portion 90, the oil blocked by the rib 100 is It drops on the intake valve 50 located below (see the dotted line shown in FIG. 6). Thereby, the injected oil can be appropriately guided to the contact portion 90 between the intake rocker arm 57 and the intake valve 50. In addition, since the oil can be efficiently supplied to the contact portion 90, the total amount of oil supplied to the lubricating structure 70 can be reduced. Thereby, the mechanical loss can be further reduced.
  • path 71b and the injection port 75 of the lubrication structure 70 which concern on this embodiment (a modification is included) were formed as a through-hole, this invention is not limited to this. Although illustration is omitted, for example, when the front end surface (front end surface) of the second fixed boss 46A serving as the seating surface of the head cover 32 is located on substantially the same plane as the contact portion 90, the second oil passage 71b.
  • the injection port 75 may be configured as a groove that is recessed in the tip surfaces of the first fixed boss 45A and the second fixed boss 46A, respectively.
  • the injection port 75 of the lubrication structure 70 which concerns on this embodiment (a modification is included) was provided in the cover fixed boss
  • the injection port 75 may be provided in at least one of the pair of left and right head fixing bosses 45 on the upper side.
  • the second oil passage 71b is omitted.
  • the second oil passage 71b and the injection port 75 are provided on the intake valve 50 side, the present invention is not limited to this.
  • the second oil passage 71b and the injection port 75 may be provided on the exhaust valve 51 side.
  • the second oil passage 71b and the injection port 75 may be provided at least on the valve side located above.
  • the present invention is applied to the motorcycle 1 as an example.
  • the present invention is not limited to this.
  • the present invention is applied to a vehicle such as a four-wheeled vehicle.
  • the present invention may be applied to this.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

[Problem] To provide a lubrication structure for a valve system that maintains appropriate lubrication performance and is capable of improving durability. [Solution] A lubrication structure (70) according to the present invention is provided with: a valve system (22) including an intake rocker shaft (55) that is supported by a cylinder head (31) constituting a cylinder (21) in an engine (4), and an intake rocker arm (57) that is supported oscillably by the intake rocker shaft (55) and that is arranged so as to be in contact with an intake valve (50); a fixing boss (44) placed facing a contact area (90) where the intake rocker arm (57) and the intake valve (50) are in contact, and used in the assembly of the cylinder (21); an oil passage (71) formed on the inside of the fixing boss (44); and a spray opening (75) formed in the fixing boss (44) so as to spray oil from inside the oil passage (71) towards the contact area (90).

Description

動弁装置の潤滑構造Lubrication structure of valve gear
　本発明は、内燃機関に設けられる動弁装置の潤滑構造に関する。 The present invention relates to a lubricating structure for a valve operating device provided in an internal combustion engine.
　吸気ポートおよび排気ポートに設けられた各バルブを開閉動作させるロッカーアーム式の動弁装置が広く知られている。 A rocker arm type valve operating device that opens and closes each valve provided in the intake port and the exhaust port is widely known.
　例えば、特許文献１には、エンジンのシリンダーヘッドに支持されたロッカーシャフトと、ロッカーシャフトに軸支されたロッカーアームと、ロッカーシャフト内に形成された通路と、ロッカーアームのジャーナル部内に形成されたオイル貯留部と、を備えた動弁装置の潤滑構造が開示されている。この種の潤滑構造において、ロッカーシャフト内のオイルは、オイル貯留部に流入してオイル通路から吐出され、ロッカーアームを揺動させるカムを潤滑する。また、吐出されたオイルは、カム等に衝突して拡散し、間接的にロッカーアーム（タペット）とバルブとの当接部分を潤滑する。 For example, in Patent Document 1, a rocker shaft supported by a cylinder head of an engine, a rocker arm supported by the rocker shaft, a passage formed in the rocker shaft, and a journal portion of the rocker arm are formed. A lubrication structure for a valve operating apparatus including an oil reservoir is disclosed. In this type of lubrication structure, the oil in the rocker shaft flows into the oil reservoir and is discharged from the oil passage to lubricate the cam that swings the rocker arm. The discharged oil collides with a cam or the like and diffuses, and indirectly lubricates the contact portion between the rocker arm (tappet) and the valve.
特開平０５－１５６９０４号公報JP 05-156904 A
　しかしながら、上記の動弁装置の潤滑構造は、エンジンの回転数の低下に伴ってオイルの吐出圧力も低下するため、吐出されたオイルを衝突・拡散させることができない場合があった。例えば、アイドリング状態では、オイルの吐出圧力は極めて低い値となるため、上記の動弁装置の潤滑構造は、タペットとバルブとの当接部分に間接的なオイルの供給を行うことができなかった。このような問題は、略水平に傾斜したシリンダーを備えたエンジンにおいて顕著となっていた。したがって、上記の動弁装置の潤滑構造は、潤滑性能の低下によって、タペット音の増加、タペットおよびバルブの摩耗および機械損失の増加等の問題を有していた。 However, the lubrication structure of the valve operating apparatus described above sometimes cannot collide and diffuse the discharged oil because the oil discharge pressure also decreases as the engine speed decreases. For example, in the idling state, the oil discharge pressure is a very low value. Therefore, the lubricating structure of the valve operating device described above cannot indirectly supply oil to the contact portion between the tappet and the valve. . Such a problem has become prominent in an engine having a cylinder inclined substantially horizontally. Therefore, the lubrication structure of the valve operating device has problems such as an increase in tappet noise, wear of tappets and valves, and an increase in mechanical loss due to a decrease in lubrication performance.
　本発明は、上記した課題を解決すべくなされたものであり、適切な潤滑性能を維持し、耐久性を向上させ得る動弁装置の潤滑構造を提供することを目的とする。 The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lubrication structure for a valve operating apparatus capable of maintaining appropriate lubrication performance and improving durability.
　本発明の動弁装置の潤滑構造は、内燃機関のシリンダーを構成するシリンダーヘッドに支持されるロッカーシャフトと、前記ロッカーシャフトに揺動可能に支持され、吸排気用のバルブに当接するように設けられるロッカーアームと、を含む動弁装置と、前記ロッカーアームと前記バルブとの当接部分に対向して配設され、前記シリンダーの組み立てに用いられる固定ボスと、前記固定ボスの内部に形成されるオイル通路と、前記オイル通路内のオイルを前記当接部分に向けて噴射するように前記固定ボスに形成される噴射部と、を備えている。 A lubrication structure for a valve operating apparatus according to the present invention is provided so that a rocker shaft supported by a cylinder head that constitutes a cylinder of an internal combustion engine, and a rocker shaft that is swingably supported by the rocker shaft and abuts on an intake / exhaust valve. A rocker arm, a fixed boss that is disposed to face a contact portion between the rocker arm and the valve, and is used for assembling the cylinder, and is formed inside the fixed boss. And an injection portion formed on the fixed boss so as to inject oil in the oil passage toward the contact portion.
　この構成によれば、噴射部は、ロッカーアームとバルブとの当接部分に対向配置される固定ボスに形成されている。また、噴射部は、該当接部分に向けて直接的にオイルを噴射する。このため、任意の部材にオイルを衝突させて間接的に拡散させる場合に比べて、オイルの噴射（吐出）圧力は低い値で足りる。したがって、内燃機関の回転数が低い場合（例えば、アイドリング時）であっても、該当接部分に対する有効なオイル供給を行うことができる。これにより、タペット音を低減することができる。また、ロッカーアーム（タペット）およびバルブの摩耗を抑制することができると共に機械損失を低減することができる。 According to this configuration, the injection portion is formed on the fixed boss arranged to face the contact portion between the rocker arm and the valve. Moreover, an injection part injects oil directly toward the applicable contact part. For this reason, compared with the case where oil is collided with an arbitrary member and indirectly diffused, the oil injection (discharge) pressure is sufficient. Therefore, even when the rotational speed of the internal combustion engine is low (for example, during idling), effective oil supply to the corresponding contact portion can be performed. Thereby, tappet sound can be reduced. Further, wear of the rocker arm (tuppet) and the valve can be suppressed, and mechanical loss can be reduced.
　この場合、前記ロッカーシャフトの内部に形成され、前記ロッカーアームの揺動部分にオイルを供給するシャフト内通路と、前記シャフト内通路と前記オイル通路とを連通する連通部と、を更に備え、前記噴射部の内径は、前記連通部の内径よりも大きく形成されていることが好ましい。 In this case, the shaft further includes a passage in the shaft that is formed inside the rocker shaft and supplies oil to a rocking portion of the rocker arm, and a communication portion that communicates the passage in the shaft and the oil passage, It is preferable that the inner diameter of the injection part is formed larger than the inner diameter of the communication part.
　この構成によれば、噴射部からのオイルの噴射量が増加する。これにより、ロッカーアームとバルブとの当接部分に対して更に有効なオイル供給を行うことができる。 According to this configuration, the amount of oil injected from the injection unit increases. Thereby, more effective oil supply can be performed to the contact portion between the rocker arm and the valve.
　この場合、前記噴射部から噴射した前記オイルを遮ると共に前記当接部分に向けて反射させるリブを更に備えていることが好ましい。 In this case, it is preferable to further include a rib that blocks the oil sprayed from the spray section and reflects the oil toward the contact portion.
　例えば、内燃機関の回転数が上昇し、オイルの噴射（吐出）圧力が上昇した場合、大量のオイルが噴射部から噴射されることとなる。この構成によれば、リブは、大量に噴射されたオイルが無駄に拡散することを抑制すると共に、ロッカーアームとバルブとの当接部分に向けてオイルを導く。これにより、動弁装置の潤滑効率の向上を図ることができる。 For example, when the rotational speed of the internal combustion engine increases and the oil injection (discharge) pressure increases, a large amount of oil is injected from the injection unit. According to this configuration, the rib prevents the oil injected in large quantities from being diffused wastefully and guides the oil toward the contact portion between the rocker arm and the valve. Thereby, the lubrication efficiency of the valve gear can be improved.
　この場合、前記動弁装置は、クランクケースから略水平に延出するシリンダーブロック上に設けられる前記シリンダーヘッドに内設され、前記リブは、前記バルブよりも上方に配設されていることが好ましい。 In this case, the valve operating device is preferably installed in the cylinder head provided on a cylinder block extending substantially horizontally from the crankcase, and the rib is disposed above the valve. .
　この構成によれば、リブに遮られたオイルは、下方に位置するバルブに滴下する。これにより、噴射したオイルを、ロッカーアームとバルブとの当接部分に適切に導くことができる。 ¡According to this configuration, the oil blocked by the ribs drops on the valve located below. Thereby, the injected oil can be appropriately guided to the contact portion between the rocker arm and the valve.
　この場合、前記リブは、前記シリンダーヘッドまたは前記シリンダーヘッドを覆うヘッドカバーの内面から、前記当接部分に向けて延設されていることが好ましい。 In this case, it is preferable that the rib is extended from the inner surface of the cylinder head or a head cover covering the cylinder head toward the contact portion.
　この構成によれば、リブに遮られたオイルを、ロッカーアームとバルブとの当接部分に適切に導くことができる。 According to this configuration, the oil blocked by the rib can be appropriately guided to the contact portion between the rocker arm and the valve.
　本発明によれば、適切な潤滑性能を維持することができると共に、動弁装置の耐久性の向上を図ることができる。 According to the present invention, appropriate lubrication performance can be maintained and durability of the valve gear can be improved.
本発明の一実施形態に係る自動二輪車を示す側面図である。1 is a side view showing a motorcycle according to an embodiment of the present invention. 本発明の一実施形態に係るエンジンを示す側面図である。It is a side view showing an engine concerning one embodiment of the present invention. 本発明の一実施形態に係るエンジンを示す側方断面図である。It is a side sectional view showing an engine concerning one embodiment of the present invention. 本発明の一実施形態に係るエンジンのシリンダーヘッドおよび動弁装置を示す斜視図である。1 is a perspective view showing a cylinder head and a valve operating apparatus of an engine according to an embodiment of the present invention. 図２のＶ－Ｖ断面図である。FIG. 5 is a VV cross-sectional view of FIG. 2. 本発明の一実施形態の変形例に係るエンジンのシリンダーヘッドおよび動弁装置を示す斜視図である。It is a perspective view which shows the cylinder head and valve operating apparatus of the engine which concern on the modification of one Embodiment of this invention.
　以下、添付の図面を参照しつつ、本発明の好適な実施形態について説明する。 Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
　図１ないし図５を参照して、本実施形態に係る動弁装置２２の潤滑構造を備える自動二輪車１について説明する。ここで、図１は自動二輪車１を示す側面図である。図２はエンジン４を示す側面図である。図３はエンジン４を示す側方断面図である。図４はシリンダーヘッド３１および動弁装置２２を示す斜視図である。図５は、図２のＶ－Ｖ断面図である。なお、各図に矢印で示す「Ｆｒ」は、自動二輪車１の前方を示している。また、以下の説明では、自動二輪車１に搭乗した乗員を基準に各方向を設定し、各図に適宜方向を示すこととする。 A motorcycle 1 having a lubricating structure for a valve gear 22 according to the present embodiment will be described with reference to FIGS. Here, FIG. 1 is a side view showing the motorcycle 1. FIG. 2 is a side view showing the engine 4. FIG. 3 is a side sectional view showing the engine 4. FIG. 4 is a perspective view showing the cylinder head 31 and the valve gear 22. 5 is a cross-sectional view taken along the line VV in FIG. Note that “Fr” indicated by an arrow in each figure indicates the front of the motorcycle 1. Further, in the following description, each direction is set with reference to an occupant who has boarded the motorcycle 1, and the direction is appropriately shown in each figure.
　図１に示すように、スクータータイプの自動二輪車１は、車体フレーム２と、車体カバー３と、エンジン４と、を備えて概略構成されている。 As shown in FIG. 1, a scooter type motorcycle 1 is schematically configured to include a body frame 2, a body cover 3, and an engine 4.
　車体フレーム２は、鋼材またはアルミニウム合金材等から成るチューブを溶接して構成されている。車体フレーム２の前部には、左右一対のフロントフォーク１０が左右操舵可能に支持されている。フロントフォーク１０の下部には、前輪１１が回転可能に支持されている。フロントフォーク１０の上部には、ハンドルバー１２が設けられている。 The body frame 2 is configured by welding a tube made of steel or aluminum alloy. A pair of left and right front forks 10 are supported at the front portion of the body frame 2 so as to be steerable left and right. A front wheel 11 is rotatably supported at the lower portion of the front fork 10. A handle bar 12 is provided on the upper portion of the front fork 10.
　車体フレーム２の後側上部には、着座シート１３が設けられている。着座シート１３の下側には、収納ボックス１４が設けられている。着座シート１３は、開閉可能に構成され、収納ボックス１４の蓋の役割を担っている。 A seating seat 13 is provided on the upper rear side of the body frame 2. A storage box 14 is provided below the seating seat 13. The seating sheet 13 is configured to be openable and closable, and serves as a lid for the storage box 14.
　車体カバー３は、フロントカウル１５と、ステップボード１６と、シートカウル１７と、を含んで構成されている。フロントカウル１５は、乗員の脚部を保護するためにフロントフォーク１０を覆うように設けられている。ステップボード１６は、フロントカウル１５の下端から後方に向けて略平坦に延設されている。着座シート１３に着座した乗員は、ステップボード１６上に両足を載置する。シートカウル１７は、収納ボックス１４を覆うように着座シート１３の下側に設けられている。 The body cover 3 includes a front cowl 15, a step board 16, and a seat cowl 17. The front cowl 15 is provided so as to cover the front fork 10 in order to protect the occupant's legs. The step board 16 extends substantially flat from the lower end of the front cowl 15 toward the rear. The occupant seated on the seat 13 places both feet on the step board 16. The seat cowl 17 is provided below the seating seat 13 so as to cover the storage box 14.
　図１ないし図３に示すように、内燃機関としてのエンジン４は、例えば、単気筒４サイクルの空冷エンジンである。エンジン４は、収納ボックス１４よりも下側で車体フレーム２に搭載されている。エンジン４は、クランクケース２０と、シリンダー２１と、動弁装置２２と、を含んで構成されている。 As shown in FIGS. 1 to 3, the engine 4 as an internal combustion engine is, for example, a single-cylinder four-cycle air-cooled engine. The engine 4 is mounted on the vehicle body frame 2 below the storage box 14. The engine 4 includes a crankcase 20, a cylinder 21, and a valve gear 22.
　クランクケース２０は、車体フレーム２の中央下部に設けられるスイングピボットＰ（図２参照）を介して上下方向に揺動可能に連結されている。クランクケース２０の左側には、変速機ケース２３が後方に向けて延設されている。変速機ケース２３の内部には、ベルト式無段変速機等の動力伝達装置（図示せず）が設けられている。変速機ケース２３の後端部には、駆動輪としての後輪２４が回転可能に支持されている（図１参照）。つまり、エンジン４は、変速機ケース２３をスイングアームとして機能させる所謂ユニットスイング式のエンジンとして構成されている。なお、変速機ケース２３の上側には、燃焼用の空気を濾過するエアークリーナー２５が配設されている（図１参照）。 The crankcase 20 is connected to be swingable in the vertical direction via a swing pivot P (see FIG. 2) provided at the center lower part of the vehicle body frame 2. A transmission case 23 extends rearward on the left side of the crankcase 20. A power transmission device (not shown) such as a belt type continuously variable transmission is provided inside the transmission case 23. A rear wheel 24 as a drive wheel is rotatably supported at the rear end portion of the transmission case 23 (see FIG. 1). That is, the engine 4 is configured as a so-called unit swing type engine in which the transmission case 23 functions as a swing arm. An air cleaner 25 that filters combustion air is disposed above the transmission case 23 (see FIG. 1).
　図３に示すように、クランクケース２０の内部には、左右方向に延びるクランクシャフト２６が軸支されている。クランクシャフト２６は、コンロッド２７を介してピストン２８に接続されている。クランクシャフト２６は、変速機ケース２３内の動力伝達装置を介して後輪２４に接続されている。 As shown in FIG. 3, a crankshaft 26 extending in the left-right direction is supported in the crankcase 20. The crankshaft 26 is connected to a piston 28 via a connecting rod 27. The crankshaft 26 is connected to the rear wheel 24 via a power transmission device in the transmission case 23.
　図２および図３に示すように、シリンダー２１は、シリンダーブロック３０と、シリンダーヘッド３１と、ヘッドカバー３２と、を含んで構成されている。 2 and 3, the cylinder 21 includes a cylinder block 30, a cylinder head 31, and a head cover 32.
　シリンダーブロック３０は、クランクケース２０の前端面から略水平に延設されている。詳細には、シリンダーブロック３０は、前方に向けて僅かに上方に傾斜するようにクランクケース２０に設けられている。シリンダーヘッド３１は、シリンダーブロック３０の先端部（前端部）に設けられている。ヘッドカバー３２は、シリンダーヘッド３１の先端面（前端面）を覆うように設けられている。 The cylinder block 30 extends substantially horizontally from the front end surface of the crankcase 20. Specifically, the cylinder block 30 is provided in the crankcase 20 so as to be inclined slightly upward toward the front. The cylinder head 31 is provided at the tip (front end) of the cylinder block 30. The head cover 32 is provided so as to cover the front end surface (front end surface) of the cylinder head 31.
　図３に示すように、シリンダーブロック３０とシリンダーヘッド３１との間には、燃焼室３３が形成されている。燃焼室３３の上側には、吸気口３４が形成されている。シリンダーヘッド３１の上面には、吸気口３４に連通する吸気ポート３５が形成されている。吸気ポート３５には、エアークリーナー２５や燃料噴射装置（図示せず）が接続されている。 As shown in FIG. 3, a combustion chamber 33 is formed between the cylinder block 30 and the cylinder head 31. An intake port 34 is formed on the upper side of the combustion chamber 33. An intake port 35 communicating with the intake port 34 is formed on the upper surface of the cylinder head 31. An air cleaner 25 and a fuel injection device (not shown) are connected to the intake port 35.
　同様に、燃焼室３３の下側には、排気口３６が形成されている。シリンダーヘッド３１の下面には、排気口３６に連通する排気ポート３７が形成されている。排気ポート３７には、排気管を介して排気マフラー（いずれも図示せず）が接続されている。 Similarly, an exhaust port 36 is formed below the combustion chamber 33. An exhaust port 37 communicating with the exhaust port 36 is formed on the lower surface of the cylinder head 31. An exhaust muffler (both not shown) is connected to the exhaust port 37 via an exhaust pipe.
　なお、シリンダーブロック３０およびシリンダーヘッド３１の左側には、クランクケース２０に連通するカムチェーン室Ｒが形成されている（図４参照）。 A cam chain chamber R communicating with the crankcase 20 is formed on the left side of the cylinder block 30 and the cylinder head 31 (see FIG. 4).
　ここで、エンジン４の作用について簡単に説明する。 Here, the operation of the engine 4 will be briefly described.
　燃料とエアークリーナー２５で清浄化された空気とは、混合気となって吸気ポート３５から吸気口３４を通って燃焼室３３に供給される。混合気は、点火プラグ（図示せず）によって着火され、燃焼室３３内で燃焼する。混合気の燃焼圧は、ピストン２８を押し出す。往復運動するピストン２８は、コンロッド２７を介してクランクシャフト２６を回転させる。クランクシャフト２６の回転力は、変速機ケース２３内の動力伝達装置を介して後輪２４を回転させる。燃焼後の排気は、排気口３６から排気ポート３７および排気管を通って外部に排出される。 Fuel and air purified by the air cleaner 25 are mixed and supplied from the intake port 35 to the combustion chamber 33 through the intake port 34. The air-fuel mixture is ignited by a spark plug (not shown) and burns in the combustion chamber 33. The combustion pressure of the mixture pushes the piston 28. The reciprocating piston 28 rotates the crankshaft 26 via the connecting rod 27. The rotational force of the crankshaft 26 rotates the rear wheel 24 via a power transmission device in the transmission case 23. Exhaust gas after combustion is discharged from the exhaust port 36 to the outside through the exhaust port 37 and the exhaust pipe.
　図４に示すように、動弁装置２２は、シリンダーヘッド３１の内部に設けられるカムハウジング４０に支持されている。カムハウジング４０の左右両壁には、それぞれ、ボールベアリング４１が装着されている。また、カムハウジング４０の上下両端部には、それぞれ、左右方向に延びるシャフト挿通孔４２，４３が穿設されている。 As shown in FIG. 4, the valve gear 22 is supported by a cam housing 40 provided inside the cylinder head 31. Ball bearings 41 are mounted on the left and right walls of the cam housing 40, respectively. Further, shaft insertion holes 42 and 43 extending in the left-right direction are formed in the upper and lower ends of the cam housing 40, respectively.
　図４および図５に示すように、カムハウジング４０には、シリンダー２１の組み立てに用いられる複数の固定ボス４４が一体に形成されている。詳細には、固定ボス４４は、４つのヘッド固定ボス４５と２つのカバー固定ボス４６とによって構成されている。 4 and 5, the cam housing 40 is integrally formed with a plurality of fixed bosses 44 used for assembling the cylinder 21. Specifically, the fixed boss 44 includes four head fixing bosses 45 and two cover fixing bosses 46.
　４つのヘッド固定ボス４５は、カムハウジング４０の左右両壁の上下両端部に配設されている。ヘッド固定ボス４５は、シリンダーヘッド３１の底面から略前方に向けて立設されている。つまり、４つのヘッド固定ボス４５は、正面視で、２行２列の格子状に配列されている。ヘッド固定ボス４５は、中心部にボルト挿通孔４７を有して略円筒状に形成されている。 The four head fixing bosses 45 are arranged at both upper and lower ends of the left and right walls of the cam housing 40. The head fixing boss 45 is erected substantially forward from the bottom surface of the cylinder head 31. That is, the four head fixing bosses 45 are arranged in a 2 × 2 grid pattern in a front view. The head fixing boss 45 has a bolt insertion hole 47 at the center and is formed in a substantially cylindrical shape.
　図２に示すように、４つのボルト挿通孔４７には、それぞれ、クランクケース２０に固定されたスタッドボルトＢ１が遊挿される。なお、ボルト挿通孔４７は、シリンダーブロック３０およびシリンダーヘッド３１を貫通するように形成されている。シリンダーブロック３０およびシリンダーヘッド３１は、貫通したスタッドボルトＢ１の先端部にナットＮを螺合させることでクランクケース２０に固定される。 2, stud bolts B1 fixed to the crankcase 20 are loosely inserted into the four bolt insertion holes 47, respectively. The bolt insertion hole 47 is formed so as to penetrate the cylinder block 30 and the cylinder head 31. The cylinder block 30 and the cylinder head 31 are fixed to the crankcase 20 by screwing a nut N into the tip of the penetrating stud bolt B1.
　図４および図５に示すように、２つのカバー固定ボス４６は、右上のヘッド固定ボス４５と左下のヘッド固定ボス４５とに固定されている。詳細には、右上のカバー固定ボス４６は、ヘッド固定ボス４５の上側で中央側に傾いて一体に設けられている。左下のカバー固定ボス４６は、ヘッド固定ボス４５の下側で外側（左側）に傾いて一体に設けられている。カバー固定ボス４６は、中心部に雌ネジ部４８を有して略円筒状に形成されている。ヘッドカバー３２は、一対のカバーボルトＢ２をカバー固定ボス４６の雌ネジ部４８に螺合させることでシリンダーヘッド３１に固定される（図２参照）。 As shown in FIGS. 4 and 5, the two cover fixing bosses 46 are fixed to the upper right head fixing boss 45 and the lower left head fixing boss 45. More specifically, the upper right cover fixing boss 46 is integrally provided on the upper side of the head fixing boss 45 while being inclined toward the center. The lower left cover fixing boss 46 is provided integrally with the lower side of the head fixing boss 45 so as to be inclined outward (left side). The cover fixing boss 46 has a female thread portion 48 at the center and is formed in a substantially cylindrical shape. The head cover 32 is fixed to the cylinder head 31 by screwing a pair of cover bolts B2 into the female screw portion 48 of the cover fixing boss 46 (see FIG. 2).
　図３に示すように、動弁装置２２は、吸気バルブ５０および排気バルブ５１と、カムシャフト５２と、吸気カム５３および排気カム５４と、吸気ロッカーシャフト５５および排気ロッカーシャフト５６と、吸気ロッカーアーム５７および排気ロッカーアーム５８と、を含んで構成されている。動弁装置２２は、所謂ＳＯＨＣ方式を採用している。 As shown in FIG. 3, the valve gear 22 includes an intake valve 50 and an exhaust valve 51, a cam shaft 52, an intake cam 53 and an exhaust cam 54, an intake rocker shaft 55 and an exhaust rocker shaft 56, and an intake rocker arm. 57 and the exhaust rocker arm 58. The valve gear 22 employs a so-called SOHC system.
　吸気バルブ５０および排気バルブ５１は、それぞれ、シリンダーヘッド３１に固定されるバルブガイド６０，６１に挿通されている。吸気バルブ５０は、吸気側バルブスプリング６２によって吸気口３４を閉止する方向に付勢されている。排気バルブ５１は、排気側バルブスプリング６３によって排気口３６を閉止する方向に付勢されている。 The intake valve 50 and the exhaust valve 51 are inserted through valve guides 60 and 61 fixed to the cylinder head 31, respectively. The intake valve 50 is urged in a direction to close the intake port 34 by an intake side valve spring 62. The exhaust valve 51 is urged in a direction to close the exhaust port 36 by an exhaust side valve spring 63.
　カムシャフト５２は、略中空円筒状に形成されている。カムシャフト５２は、左右一対のボールベアリング４１に軸支されている（図４参照）。カムシャフト５２の中央領域には、吸気カム５３および排気カム５４が並設されている。吸気カム５３および排気カム５４は、所謂偏心カムであって、略同一形状に形成されている。 The camshaft 52 is formed in a substantially hollow cylindrical shape. The camshaft 52 is pivotally supported by a pair of left and right ball bearings 41 (see FIG. 4). In the central region of the camshaft 52, an intake cam 53 and an exhaust cam 54 are juxtaposed. The intake cam 53 and the exhaust cam 54 are so-called eccentric cams and are formed in substantially the same shape.
　図４および図５に示すように、カムシャフト５２の左端部は、ボールベアリング４１を貫通してカムチェーン室Ｒまで延びている。カムシャフト５２の左端部には、カムスプロケット６４が固定されている。上記したクランクシャフト２６の左端部には、カムドライブスプロケット（図示せず）が固定されている。カムスプロケット６４とカムドライブスプロケットとの間には、カムチェーン６５が掛け渡されている。 As shown in FIGS. 4 and 5, the left end portion of the cam shaft 52 extends through the ball bearing 41 to the cam chain chamber R. A cam sprocket 64 is fixed to the left end portion of the camshaft 52. A cam drive sprocket (not shown) is fixed to the left end portion of the crankshaft 26 described above. A cam chain 65 is stretched between the cam sprocket 64 and the cam drive sprocket.
　図３および図４に示すように、吸気ロッカーシャフト５５および排気ロッカーシャフト５６は、略中空円筒状に形成されている。吸気ロッカーシャフト５５および排気ロッカーシャフト５６は、カムハウジング４０（シリンダーヘッド３１）に支持されている。詳細には、吸気ロッカーシャフト５５は、上側のシャフト挿通孔４２に装着されている。排気ロッカーシャフト５６は、下側のシャフト挿通孔４３に装着されている。 As shown in FIGS. 3 and 4, the intake rocker shaft 55 and the exhaust rocker shaft 56 are formed in a substantially hollow cylindrical shape. The intake rocker shaft 55 and the exhaust rocker shaft 56 are supported by the cam housing 40 (cylinder head 31). Specifically, the intake rocker shaft 55 is mounted in the upper shaft insertion hole 42. The exhaust rocker shaft 56 is mounted in the lower shaft insertion hole 43.
　図５に示すように、吸気ロッカーシャフト５５および排気ロッカーシャフト５６の左端部には、それぞれ、係合溝５５ａ，５６ａが凹設されている。上下一対の係合溝５５ａ，５６ａには、規制プレート６６が係止される。規制プレート６６は、両シャフト５５，５６の間に架設され、プレートボルトＢ３によってカムハウジング４０に固定される。これにより、各ロッカーシャフト５５，５６は、左右方向の移動を規制される。 As shown in FIG. 5, engagement grooves 55 a and 56 a are respectively provided in the left end portions of the intake rocker shaft 55 and the exhaust rocker shaft 56. The restriction plate 66 is locked to the pair of upper and lower engagement grooves 55a and 56a. The restriction plate 66 is installed between the shafts 55 and 56, and is fixed to the cam housing 40 by a plate bolt B3. Thereby, each rocker shaft 55 and 56 is restricted from moving in the left-right direction.
　図３および図４に示すように、吸気ロッカーアーム５７および排気ロッカーアーム５８は、上下方向に長く形成されている。吸気ロッカーアーム５７および排気ロッカーアーム５８は、それぞれ、長手方向略中央に形成されるボス部５７ａ，５８ａと、一端部に形成されるスリッパ部５７ｂ，５８ｂと、他端部に形成されるアーム部５７ｃ，５８ｃと、を有している。 As shown in FIGS. 3 and 4, the intake rocker arm 57 and the exhaust rocker arm 58 are long in the vertical direction. The intake rocker arm 57 and the exhaust rocker arm 58 are respectively boss portions 57a and 58a formed at the substantially central portion in the longitudinal direction, slipper portions 57b and 58b formed at one end portion, and an arm portion formed at the other end portion. 57c, 58c.
　吸気ロッカーアーム５７は、ボス部５７ａに挿通する吸気ロッカーシャフト５５に揺動可能に支持されている。吸気ロッカーアーム５７のスリッパ部５７ｂは、吸気カム５３に当接している。吸気ロッカーアーム５７のアーム部５７ｃには、吸気タペット６７が固定されている。吸気ロッカーアーム５７は、吸気タペット６７を介して吸気バルブ５０の先端部に当接するように設けられている。 The intake rocker arm 57 is swingably supported by an intake rocker shaft 55 inserted through the boss portion 57a. The slipper portion 57 b of the intake rocker arm 57 is in contact with the intake cam 53. An intake tappet 67 is fixed to the arm portion 57 c of the intake rocker arm 57. The intake rocker arm 57 is provided so as to come into contact with the tip of the intake valve 50 via an intake tappet 67.
　同様に、排気ロッカーアーム５８は、ボス部５８ａに挿通する排気ロッカーシャフト５６に揺動可能に支持されている。排気ロッカーアーム５８のスリッパ部５８ｂは、排気カム５４に当接している。排気ロッカーアーム５８のアーム部５８ｃには、排気タペット６８が固定されている。排気ロッカーアーム５８は、排気タペット６８を介して排気バルブ５１の先端部に当接するように設けられている。 Similarly, the exhaust rocker arm 58 is swingably supported by an exhaust rocker shaft 56 inserted through the boss portion 58a. The slipper portion 58 b of the exhaust rocker arm 58 is in contact with the exhaust cam 54. An exhaust tappet 68 is fixed to the arm portion 58 c of the exhaust rocker arm 58. The exhaust rocker arm 58 is provided so as to come into contact with the tip of the exhaust valve 51 via the exhaust tappet 68.
　ここで、図３を参照して、動弁装置２２の作用について説明する。 Here, the operation of the valve gear 22 will be described with reference to FIG.
　エンジン４（クランクシャフト２６）の回転力は、カムチェーン６５を介してカムシャフト５２を回転させる。カムシャフト５２と共に回転する各カム５３，５４は、各ロッカーアーム５７，５８のスリッパ部５７ｂ，５８ｂに対し押圧と押圧解除とを繰り返す。これにより、各ロッカーアーム５７，５８は、それぞれ、各ロッカーシャフト５５，５６を支点に揺動する。揺動する吸気ロッカーアーム５７は、吸気タペット６７を介して吸気バルブ５０の押圧と押圧解除を繰り返す。同様に、揺動する排気ロッカーアーム５８は、排気タペット６８を介して排気バルブ５１の押圧と押圧解除を繰り返す。各バルブ５０，５１は、軸方向に往復移動し、吸気口３４および排気口３６を開閉させる。これにより、燃焼室３３に対する吸排気が行われる。 Rotational force of the engine 4 (crankshaft 26) rotates the camshaft 52 via the cam chain 65. The cams 53 and 54 that rotate together with the camshaft 52 repeatedly press and release the slipper portions 57b and 58b of the rocker arms 57 and 58, respectively. As a result, the rocker arms 57 and 58 swing around the rocker shafts 55 and 56, respectively. The swinging intake rocker arm 57 repeats pressing and releasing of the intake valve 50 via the intake tappet 67. Similarly, the swinging exhaust rocker arm 58 repeatedly presses and releases the exhaust valve 51 via the exhaust tappet 68. The valves 50 and 51 reciprocate in the axial direction to open and close the intake port 34 and the exhaust port 36. As a result, intake and exhaust of the combustion chamber 33 is performed.
　ところで、上記した動弁装置２２は、可動部分に冷却および潤滑のためのオイルを供給する構造（以下、「潤滑構造７０」と呼ぶ。）を備えている。以下、動弁装置２２の潤滑構造７０について説明する。 Incidentally, the valve operating device 22 described above has a structure for supplying oil for cooling and lubrication to the movable part (hereinafter referred to as “lubricating structure 70”). Hereinafter, the lubricating structure 70 of the valve gear 22 will be described.
　図５に示すように、潤滑構造７０は、右上の固定ボス４４の内部に形成されるオイル通路７１と、吸気ロッカーシャフト５５の内部に形成されるシャフト内通路７２と、右上の固定ボス４４に形成される噴射部としての噴射口７５と、を含んで構成されている。なお、以下、説明の便宜上、右上のヘッド固定ボス４５を「第１固定ボス４５Ａ」と呼び、右上のカバー固定ボス４６を「第２固定ボス４６Ａ」と呼ぶこととする。 As shown in FIG. 5, the lubrication structure 70 includes an oil passage 71 formed in the upper right fixed boss 44, an in-shaft passage 72 formed in the intake rocker shaft 55, and the upper right fixed boss 44. And an injection port 75 as an injection portion to be formed. Hereinafter, for convenience of description, the upper right head fixing boss 45 is referred to as a “first fixing boss 45A”, and the upper right cover fixing boss 46 is referred to as a “second fixing boss 46A”.
　オイル通路７１は、第１オイル通路７１ａと第２オイル通路７１ｂとを有している。第１オイル通路７１ａは、第１固定ボス４５Ａのボルト挿通孔４７とこれを貫通するスタッドボルトＢ１との隙間によって構成されている。第２オイル通路７１ｂは、第１オイル通路７１ａから第２固定ボス４６Ａの内部に亘って構成されている。雌ネジ部４８にカバーボルトＢ２を固定した状態で、カバーボルトＢ２の先端部と第２固定ボス４６Ａの底部との間には、噴射オイル貯留部７６が形成されている。 The oil passage 71 has a first oil passage 71a and a second oil passage 71b. The first oil passage 71a is constituted by a gap between the bolt insertion hole 47 of the first fixed boss 45A and the stud bolt B1 penetrating therethrough. The second oil passage 71b extends from the first oil passage 71a to the inside of the second fixed boss 46A. In a state where the cover bolt B2 is fixed to the female screw portion 48, an injection oil storage portion 76 is formed between the tip end portion of the cover bolt B2 and the bottom portion of the second fixing boss 46A.
　第１オイル通路７１ａの下側内面には、連通部としての略円形の連通孔８０が開口している。連通孔８０は、内側（第１オイル通路７１ａ側）から座ぐりされている。連通孔８０は、シャフト内通路７２と第１オイル通路７１ａとを連通させるように形成されている。 A substantially circular communication hole 80 as a communication portion is opened on the lower inner surface of the first oil passage 71a. The communication hole 80 is countersunk from the inside (the first oil passage 71a side). The communication hole 80 is formed so as to connect the in-shaft passage 72 and the first oil passage 71a.
　シャフト内通路７２は、吸気ロッカーシャフト５５の軸方向に延設されている。シャフト内通路７２の内面には、吸気ロッカーアーム５７の揺動部分（摺動部分）に対応する位置にシャフト内連通孔８１が穿設されている。吸気ロッカーアーム５７のボス部５７ａには、吸気ロッカーシャフト５５との揺動部分に吸気側オイル貯留部８２が内設されている。シャフト内連通孔８１は、シャフト内通路７２と吸気側オイル貯留部８２とを連通させるように形成されている。つまり、シャフト内通路７２は、吸気ロッカーアーム５７の揺動部分にオイルを供給するように構成されている。 The in-shaft passage 72 extends in the axial direction of the intake rocker shaft 55. An in-shaft communication hole 81 is formed in the inner surface of the in-shaft passage 72 at a position corresponding to the swinging portion (sliding portion) of the intake rocker arm 57. The boss portion 57 a of the intake rocker arm 57 is provided with an intake side oil reservoir 82 at a swinging portion with the intake rocker shaft 55. The in-shaft communication hole 81 is formed so as to allow the in-shaft passage 72 and the intake-side oil reservoir 82 to communicate with each other. That is, the in-shaft passage 72 is configured to supply oil to the swinging portion of the intake rocker arm 57.
　吸気ロッカーアーム５７のボス部５７ａには、吸気側オイル貯留部８２に連通する吸気側開口８３が形成されている。吸気側開口８３は、吸気カム５３と吸気ロッカーアーム５７のスリッパ部５７ｂとの接触部分に向けて設けられている。 An intake side opening 83 communicating with the intake side oil reservoir 82 is formed in the boss portion 57 a of the intake rocker arm 57. The intake side opening 83 is provided toward a contact portion between the intake cam 53 and the slipper portion 57 b of the intake rocker arm 57.
　ところで、図４および図５に示すように、第１固定ボス４５Ａおよび第２固定ボス４６Ａは、吸気ロッカーアーム５７に対して外側（右側）から対向するように設けられている。詳細には、第１固定ボス４５Ａは、吸気ロッカーアーム５７のボス部５７ａとアーム部５７ｃとの間の部分に対向して配設されている。第２固定ボス４６Ａは、吸気ロッカーアーム５７の吸気タペット６７と吸気バルブ５０との当接部分９０に対向して配設されている。 Incidentally, as shown in FIGS. 4 and 5, the first fixed boss 45A and the second fixed boss 46A are provided to face the intake rocker arm 57 from the outside (right side). Specifically, the first fixed boss 45 </ b> A is disposed to face a portion between the boss portion 57 a and the arm portion 57 c of the intake rocker arm 57. The second fixed boss 46 </ b> A is disposed to face the contact portion 90 between the intake tappet 67 of the intake rocker arm 57 and the intake valve 50.
　噴射口７５は、オイル通路７１内のオイルを吸気タペット６７と吸気バルブ５０との当接部分９０（以下、単に「当接部分９０」とも呼ぶ。）に向けて噴射するように第２固定ボス４６Ａに形成されている。噴射口７５は、略円形の開口であって、第２固定ボス４６Ａの側壁に穿設されている。詳細には、噴射口７５は、正面視で、第２固定ボス４６Ａの斜め左側面に形成されている。また、噴射口７５は、当接部分９０と略同一平面上に位置している（図４参照）。噴射口７５の内径は、連通孔８０の内径よりも大きく形成されている。 The injection port 75 is configured to inject the oil in the oil passage 71 toward a contact portion 90 between the intake tappet 67 and the intake valve 50 (hereinafter also simply referred to as “contact portion 90”). 46A. The injection port 75 is a substantially circular opening, and is formed in the side wall of the second fixed boss 46A. Specifically, the injection port 75 is formed on the oblique left side surface of the second fixed boss 46A in front view. Moreover, the injection port 75 is located on the substantially same plane as the contact part 90 (refer FIG. 4). The inner diameter of the injection port 75 is formed larger than the inner diameter of the communication hole 80.
　次に、図５を参照して、動弁装置２２の潤滑構造７０の作用（オイルの流れ）について説明する。 Next, the operation (oil flow) of the lubricating structure 70 of the valve gear 22 will be described with reference to FIG.
　冷却および潤滑のためのオイルは、オイルポンプ（図示せず）によって圧送される。圧送されたオイルは、第１オイル通路７１ａに供給される。なお、オイルポンプは、クランクシャフト２６の回転によって駆動される。 -Oil for cooling and lubrication is pumped by an oil pump (not shown). The pumped oil is supplied to the first oil passage 71a. The oil pump is driven by the rotation of the crankshaft 26.
　第１オイル通路７１ａに供給されたオイルは、連通孔８０を通ってシャフト内通路７２に導かれる。シャフト内通路７２に供給されたオイルは、シャフト内連通孔８１を通って吸気側オイル貯留部８２に導かれる。吸気側オイル貯留部８２内のオイルは、吸気ロッカーアーム５７のボス部５７ａを潤滑する。 The oil supplied to the first oil passage 71a is guided to the in-shaft passage 72 through the communication hole 80. The oil supplied to the in-shaft passage 72 is guided to the intake side oil reservoir 82 through the in-shaft communication hole 81. The oil in the intake side oil reservoir 82 lubricates the boss portion 57 a of the intake rocker arm 57.
　吸気側オイル貯留部８２内のオイルは、吸気側開口８３から吸気カム５３と吸気ロッカーアーム５７のスリッパ部５７ｂとの接触部分に向けて吐出される。シリンダー２１が略水平に設けられているため、吸気側開口８３から吐出されたオイルは、上方に位置する吸気ロッカーシャフト５５側から下方に位置する排気ロッカーシャフト５６側に向けて落下しながら拡散する。このため、吸気側開口８３から吐出されたオイルは、各ボールベアリング４１、吸気カム５３、排気カム５４、スリッパ部５７ｂおよびスリッパ部５８ｂを潤滑する。 The oil in the intake side oil reservoir 82 is discharged from the intake side opening 83 toward the contact portion between the intake cam 53 and the slipper portion 57 b of the intake rocker arm 57. Since the cylinder 21 is provided substantially horizontally, the oil discharged from the intake side opening 83 is diffused while dropping from the intake rocker shaft 55 located above to the exhaust rocker shaft 56 located below. . For this reason, the oil discharged from the intake side opening 83 lubricates each ball bearing 41, the intake cam 53, the exhaust cam 54, the slipper portion 57b, and the slipper portion 58b.
　ところで、オイルポンプによるオイルの供給圧力は、エンジン４（クランクシャフト２６）の回転数の増減に略比例して変化する。すなわち、エンジン４の回転数が高くなるほどオイルポンプの圧力が高くなり、エンジン４の回転数が低くなるほどオイルポンプの圧力が低くなる。例えば、自動二輪車１が走行中である場合、オイルポンプの圧力が十分に高くなるため、潤滑に十分な量のオイルが、吸気側開口８３等から流出する。また、流出したオイルは、各カム５３，５４の回転や各ロッカーアーム５７，５８の揺動によって、飛散（拡散）する。このため、飛散したオイルは、各バルブ５０，５１と各タペット６７，６８との当接部分９０にも供給され、当接部分９０を潤滑する。 Incidentally, the oil supply pressure by the oil pump changes substantially in proportion to the increase / decrease in the rotational speed of the engine 4 (crankshaft 26). That is, the higher the rotational speed of the engine 4, the higher the pressure of the oil pump, and the lower the rotational speed of the engine 4, the lower the pressure of the oil pump. For example, when the motorcycle 1 is traveling, the pressure of the oil pump becomes sufficiently high, so that a sufficient amount of oil flows out from the intake side opening 83 and the like. Further, the oil that has flowed out is scattered (diffused) by the rotation of the cams 53 and 54 and the swinging of the rocker arms 57 and 58. For this reason, the scattered oil is also supplied to the contact portion 90 between each valve 50, 51 and each tappet 67, 68 to lubricate the contact portion 90.
　これに対し、例えば、自動二輪車１が信号待ち等で停車し、エンジン４がアイドリング中である場合、オイルポンプの圧力が低下するため、吸気側開口８３等からのオイルの流出量が減少する。この場合、上方に位置する吸気バルブ５０と吸気タペット６７との当接部分９０にオイルを供給することが困難になる。そこで、本実施形態に係る動弁装置２２の潤滑構造７０は、噴射口７５からオイルを噴射して当接部分９０を潤滑するように構成されている。 On the other hand, for example, when the motorcycle 1 stops due to a signal or the like and the engine 4 is idling, the pressure of the oil pump decreases, so the amount of oil flowing out from the intake side opening 83 or the like decreases. In this case, it becomes difficult to supply oil to the contact portion 90 between the intake valve 50 and the intake tappet 67 located above. Therefore, the lubrication structure 70 of the valve gear 22 according to the present embodiment is configured to inject oil from the injection port 75 and lubricate the contact portion 90.
　すなわち、第１オイル通路７１ａに供給されたオイルは、第２オイル通路７１ｂを通って第２固定ボス４６Ａの噴射オイル貯留部７６に導かれる。噴射オイル貯留部７６内のオイルは、オイルポンプによるオイルの供給圧力によって噴射口７５から噴射する。噴射口７５は、左上方に向けてオイルを噴射する。噴射口７５から噴射したオイルは、放物線（図４に示す点線参照）を描いて吸気バルブ５０と吸気タペット６７との当接部分９０に付着し、当接部分９０を潤滑する。なお、噴射口７５から噴射したオイルは、落下しながら拡散して排気バルブ５１と排気タペット６８との当接部分等を潤滑する。 That is, the oil supplied to the first oil passage 71a is guided to the injection oil reservoir 76 of the second fixed boss 46A through the second oil passage 71b. The oil in the injection oil reservoir 76 is injected from the injection port 75 by the oil supply pressure by the oil pump. The injection port 75 injects oil toward the upper left. The oil injected from the injection port 75 draws a parabola (see the dotted line shown in FIG. 4) and adheres to the contact portion 90 between the intake valve 50 and the intake tappet 67 and lubricates the contact portion 90. The oil injected from the injection port 75 diffuses while dropping and lubricates the contact portion between the exhaust valve 51 and the exhaust tappet 68.
　以上説明した本実施形態に係る動弁装置２２の潤滑構造７０によれば、噴射口７５は、吸気ロッカーアーム５７（吸気タペット６７）と吸気バルブ５０との当接部分９０に対向配置される第２固定ボス４６Ａに形成されている。また、噴射口７５は、当接部分９０に向けて直接的にオイルを噴射する。このため、任意の部材にオイルを衝突させて間接的に拡散させる場合に比べて、オイルの噴射（吐出）圧力は低い値で足りる。したがって、エンジン４の回転数が低い場合（例えばアイドリング時）であっても、当接部分９０に対する有効なオイル供給を行うことができる。これにより、タペット音を低減することができる。また、吸気ロッカーアーム５７（吸気タペット６７）および吸気バルブ５０の摩耗を抑制することができると共に機械損失を低減することができる。 According to the lubrication structure 70 of the valve gear 22 according to the present embodiment described above, the injection port 75 is disposed to face the contact portion 90 between the intake rocker arm 57 (intake tappet 67) and the intake valve 50. Two fixed bosses 46A are formed. The injection port 75 directly injects oil toward the abutting portion 90. For this reason, compared with the case where oil is collided with an arbitrary member and indirectly diffused, the oil injection (discharge) pressure is sufficient. Therefore, even when the rotational speed of the engine 4 is low (for example, during idling), effective oil supply to the contact portion 90 can be performed. Thereby, tappet sound can be reduced. Further, wear of the intake rocker arm 57 (intake tappet 67) and the intake valve 50 can be suppressed, and mechanical loss can be reduced.
　また、本実施形態に係る動弁装置２２の潤滑構造７０によれば、噴射口７５を連通孔８０よりも大径にすることで、噴射口７５からのオイルの噴射量が増加する。これにより、吸気ロッカーアーム５７（吸気タペット６７）と吸気バルブ５０との当接部分９０に対して更に有効なオイル供給を行うことができる。 Further, according to the lubrication structure 70 of the valve gear 22 according to the present embodiment, the injection amount of oil from the injection port 75 is increased by making the injection port 75 larger in diameter than the communication hole 80. Accordingly, more effective oil supply can be performed to the contact portion 90 between the intake rocker arm 57 (intake tappet 67) and the intake valve 50.
　次に、図６を参照して、本実施形態の変形例に係る動弁装置２２の潤滑構造７０について説明する。図６はシリンダーヘッド３１および動弁装置２２を示す斜視図である。なお、上記した実施形態に係る動弁装置２２の潤滑構造７０と同様の構成については、同一の符号を付し、説明を省略する。 Next, a lubricating structure 70 of the valve gear 22 according to a modification of the present embodiment will be described with reference to FIG. FIG. 6 is a perspective view showing the cylinder head 31 and the valve gear 22. In addition, about the structure similar to the lubrication structure 70 of the valve operating apparatus 22 which concerns on above-described embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
　本変形例に係る動弁装置２２の潤滑構造７０は、噴射口７５から噴射したオイルを遮ると共に吸気タペット６７と吸気バルブ５０との当接部分９０に向けて反射させるリブ１００を更に備えている。 The lubrication structure 70 of the valve gear 22 according to the present modification further includes a rib 100 that blocks oil injected from the injection port 75 and reflects the oil toward the contact portion 90 between the intake tappet 67 and the intake valve 50. .
　リブ１００は、矩形板状に形成されている。リブ１００は、吸気バルブ５０よりも上方に配設されている。リブ１００は、シリンダーヘッド３１の上部内面から当接部分９０に向けて延設されている。リブ１００は、吸気バルブ５０よりもカムチェーン室Ｒ側となる位置で、シリンダーヘッド３１の上部内面から垂下るように設けられている。リブ１００の先端部（下端部）は、当接部分９０の上方近傍に位置している。なお、リブ１００は、シリンダーヘッド３１を覆うヘッドカバー３２の上部内面に設けられていてもよい。 The rib 100 is formed in a rectangular plate shape. The rib 100 is disposed above the intake valve 50. The rib 100 extends from the upper inner surface of the cylinder head 31 toward the contact portion 90. The rib 100 is provided so as to hang from the upper inner surface of the cylinder head 31 at a position closer to the cam chain chamber R than the intake valve 50. The leading end (lower end) of the rib 100 is located near the upper portion of the contact portion 90. The rib 100 may be provided on the upper inner surface of the head cover 32 that covers the cylinder head 31.
　例えば、エンジン４の回転数が上昇し、オイルポンプによるオイルの供給（噴射）圧力が上昇した場合、大量のオイルが噴射口７５から噴射されることとなる。以上説明した本実施形態の変形例に係る動弁装置２２の潤滑構造７０によれば、リブ１００は、大量に噴射されたオイルが無駄に拡散することを抑制すると共に、吸気ロッカーアーム５７（吸気タペット６７）と吸気バルブ５０との当接部分９０に向けてオイルを導く（図６に示す点線参照）。これにより、動弁装置２２の潤滑効率の向上を図ることができる。 For example, when the rotation speed of the engine 4 increases and the oil supply (injection) pressure by the oil pump increases, a large amount of oil is injected from the injection port 75. According to the lubrication structure 70 of the valve gear 22 according to the modified example of the present embodiment described above, the rib 100 prevents the oil injected in large quantities from being diffused wastefully, and the intake rocker arm 57 (intake air). Oil is guided toward the contact portion 90 between the tappet 67) and the intake valve 50 (see the dotted line shown in FIG. 6). Thereby, the lubrication efficiency of the valve gear 22 can be improved.
　また、本実施形態の変形例に係る動弁装置２２の潤滑構造７０によれば、リブ１００の先端が当接部分９０の上方近傍に位置しているため、リブ１００に遮られたオイルは、下方に位置する吸気バルブ５０に滴下する（図６に示す点線参照）。これにより、噴射したオイルを、吸気ロッカーアーム５７と吸気バルブ５０との当接部分９０に適切に導くことができる。また、当接部分９０に効率良くオイルを供給することができるため、潤滑構造７０に供給するオイルの総量を減少させることができる。これにより、更に機械損失を低減することができる。 Further, according to the lubrication structure 70 of the valve gear 22 according to the modification of the present embodiment, since the tip of the rib 100 is located in the vicinity of the upper portion of the contact portion 90, the oil blocked by the rib 100 is It drops on the intake valve 50 located below (see the dotted line shown in FIG. 6). Thereby, the injected oil can be appropriately guided to the contact portion 90 between the intake rocker arm 57 and the intake valve 50. In addition, since the oil can be efficiently supplied to the contact portion 90, the total amount of oil supplied to the lubricating structure 70 can be reduced. Thereby, the mechanical loss can be further reduced.
　なお、本実施形態（変形例を含む。）に係る潤滑構造７０の第２オイル通路７１ｂおよび噴射口７５は、貫通する孔として形成されていたが、本発明はこれに限定されない。図示は省略するが、例えば、ヘッドカバー３２の座面となる第２固定ボス４６Ａの先端面（前端面）が、当接部分９０と略同一平面上に位置している場合、第２オイル通路７１ｂおよび噴射口７５は、それぞれ、第１固定ボス４５Ａおよび第２固定ボス４６Ａの先端面に凹設される溝として構成してもよい。 In addition, although the 2nd oil channel | path 71b and the injection port 75 of the lubrication structure 70 which concern on this embodiment (a modification is included) were formed as a through-hole, this invention is not limited to this. Although illustration is omitted, for example, when the front end surface (front end surface) of the second fixed boss 46A serving as the seating surface of the head cover 32 is located on substantially the same plane as the contact portion 90, the second oil passage 71b. The injection port 75 may be configured as a groove that is recessed in the tip surfaces of the first fixed boss 45A and the second fixed boss 46A, respectively.
　なお、本実施形態（変形例を含む。）に係る潤滑構造７０の噴射口７５は、カバー固定ボス４６（第２固定ボス４６Ａ）に設けられていたが、本発明はこれに限定されない。例えば、噴射口７５は、上側の左右一対のヘッド固定ボス４５の少なくとも一方に設けられていてもよい。この場合、第２オイル通路７１ｂは省略される。なお、第２オイル通路７１ｂおよび噴射口７５は、吸気バルブ５０側に設けられていたが、本発明はこれに限定されない。例えば、吸気バルブ５０側に加えて、第２オイル通路７１ｂおよび噴射口７５は、排気バルブ５１側に設けられていてもよい。第２オイル通路７１ｂおよび噴射口７５は、少なくとも上方に位置するバルブ側に設けられていればよい。 In addition, although the injection port 75 of the lubrication structure 70 which concerns on this embodiment (a modification is included) was provided in the cover fixed boss | hub 46 (2nd fixed boss | hub 46A), this invention is not limited to this. For example, the injection port 75 may be provided in at least one of the pair of left and right head fixing bosses 45 on the upper side. In this case, the second oil passage 71b is omitted. Although the second oil passage 71b and the injection port 75 are provided on the intake valve 50 side, the present invention is not limited to this. For example, in addition to the intake valve 50 side, the second oil passage 71b and the injection port 75 may be provided on the exhaust valve 51 side. The second oil passage 71b and the injection port 75 may be provided at least on the valve side located above.
　なお、上記した本実施形態（変形例を含む。）の説明では、一例として、本発明を自動二輪車１に適用した場合を示したが、これに限らず、例えば、四輪車等の車両に対して本発明を適用してもよい。 In the above description of the present embodiment (including modifications), the case where the present invention is applied to the motorcycle 1 is shown as an example. However, the present invention is not limited to this. For example, the present invention is applied to a vehicle such as a four-wheeled vehicle. The present invention may be applied to this.
　なお、上記した本発明の実施形態（変形例を含む。）の説明は、本発明に係る動弁装置の潤滑構造における好適な実施の形態を説明しているため、技術的に好ましい種々の限定を付している場合もあるが、本発明の技術範囲は、特に本発明を限定する記載がない限り、これらの態様に限定されるものではない。さらに、上記した本発明の実施形態における構成要素は適宜、既存の構成要素等との置き換えが可能であり、かつ、他の既存の構成要素との組合せを含む様々なバリエーションが可能であり、上記した本発明の実施形態の記載をもって、特許請求の範囲に記載された発明の内容を限定するものではない。 In addition, since description of embodiment (it contains a modification) of the above-mentioned this invention demonstrates suitable embodiment in the lubrication structure of the valve operating apparatus which concerns on this invention, various technically preferable restrictions are described. However, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. Furthermore, the components in the embodiment of the present invention described above can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention is not intended to limit the content of the invention described in the claims.
　　　４　エンジン（内燃機関）
　　　２０　クランクケース
　　　２１　シリンダー
　　　２２　動弁装置
　　　３０　シリンダーブロック
　　　３１　シリンダーヘッド
　　　３２　ヘッドカバー
　　　４４　固定ボス
　　　４５Ａ　第１固定ボス
　　　４６Ａ　第２固定ボス
　　　５０　吸気バルブ
　　　５１　排気バルブ
　　　５５　吸気ロッカーシャフト
　　　５６　排気ロッカーシャフト
　　　５７　吸気ロッカーアーム
　　　５８　排気ロッカーアーム
　　　７０　潤滑構造
　　　７１　オイル通路
　　　７２　シャフト内通路
　　　７５　噴射口（噴射部）
　　　８０　連通孔（連通部）
　　　９０　当接部分
　　　１００　リブ 4 engine (internal combustion engine)
20 Crankcase 21 Cylinder 22 Valve operating device 30 Cylinder block 31 Cylinder head 32 Head cover 44 Fixed boss 45A First fixed boss 46A Second fixed boss 50 Intake valve 51 Exhaust valve 55 Intake rocker shaft 56 Exhaust rocker shaft 57 Intake rocker arm 58 Exhaust Rocker arm 70 Lubrication structure 71 Oil passage 72 Shaft passage 75 Injection port (injection part)
80 communication hole (communication part)
90 Contact part 100 Rib

Claims (5)

  1. 　内燃機関のシリンダーを構成するシリンダーヘッドに支持されるロッカーシャフトと、前記ロッカーシャフトに揺動可能に支持され、吸排気用のバルブに当接するように設けられるロッカーアームと、を含む動弁装置と、
    　前記ロッカーアームと前記バルブとの当接部分に対向して配設され、前記シリンダーの組み立てに用いられる固定ボスと、
    　前記固定ボスの内部に形成されるオイル通路と、
    　前記オイル通路内のオイルを前記当接部分に向けて噴射するように前記固定ボスに形成される噴射部と、を備えていることを特徴とする動弁装置の潤滑構造。     A valve operating system comprising: a rocker shaft supported by a cylinder head constituting a cylinder of an internal combustion engine; and a rocker arm that is swingably supported by the rocker shaft and is provided to come into contact with a valve for intake and exhaust. ,
    A fixed boss disposed to face the abutting portion of the rocker arm and the valve, and used for assembling the cylinder;
    An oil passage formed inside the fixed boss;
    A lubricating structure for a valve operating apparatus, comprising: an injection portion formed on the fixed boss so as to inject oil in the oil passage toward the contact portion.
  2. 　前記ロッカーシャフトの内部に形成され、前記ロッカーアームの揺動部分にオイルを供給するシャフト内通路と、
    　前記シャフト内通路と前記オイル通路とを連通する連通部と、を更に備え、
    　前記噴射部の内径は、前記連通部の内径よりも大きく形成されていることを特徴とする請求項１に記載の動弁装置の潤滑構造。     A passage in the shaft that is formed inside the rocker shaft and supplies oil to a rocking portion of the rocker arm;
    A communication portion that communicates the in-shaft passage and the oil passage;
    2. The lubricating structure for a valve operating apparatus according to claim 1, wherein an inner diameter of the injection portion is formed larger than an inner diameter of the communication portion.
  3. 　前記噴射部から噴射した前記オイルを遮ると共に前記当接部分に向けて反射させるリブを更に備えていることを特徴とする請求項１または２に記載の動弁装置の潤滑構造。 3. The lubrication structure for a valve operating apparatus according to claim 1, further comprising a rib that blocks the oil sprayed from the spray section and reflects the oil toward the contact portion.
  4. 　前記動弁装置は、クランクケースから略水平に延出するシリンダーブロック上に設けられる前記シリンダーヘッドに内設され、
    　前記リブは、前記バルブよりも上方に配設されていることを特徴とする請求項３に記載の動弁装置の潤滑構造。     The valve gear is installed in the cylinder head provided on a cylinder block extending substantially horizontally from a crankcase,
    The lubrication structure for a valve operating apparatus according to claim 3, wherein the rib is disposed above the valve.
  5. 　前記リブは、前記シリンダーヘッドまたは前記シリンダーヘッドを覆うヘッドカバーの内面から、前記当接部分に向けて延設されていることを特徴とする請求項３または４に記載の動弁装置の潤滑構造。 The lubrication structure for a valve operating apparatus according to claim 3 or 4, wherein the rib is extended from the inner surface of the cylinder head or a head cover covering the cylinder head toward the contact portion.
PCT/JP2015/054093 2014-03-10 2015-02-16 Lubrication structure for valve system WO2015137046A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201580000646.2A CN106062326B (en) 2014-03-10 2015-02-16 The lubrication system of valve gear

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JP6589746B2 (en) * 2016-06-08 2019-10-16 日立オートモティブシステムズ株式会社 Actuator of link mechanism for internal combustion engine
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JPH0330691B2 (en) * 1983-06-07 1991-05-01 Honda Motor Co Ltd
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JP2013231408A (en) * 2012-05-01 2013-11-14 Yamaha Motor Co Ltd Straddle-type vehicle

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