JPH09144520A - Oil supply system for 4-cycle internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply sufficient oil to a total unit of a valve system by a small number of part items. SOLUTION: In a four-cycle internal combustion engine mounted in a vehicle by an attitude large front tilting a cylinder, oil passages t13, t14, guiding oil supplied from an oil pump to an upper side wall 34b of a cylinder head cover 34 large front tilted similarly to the cylinder 32, are formed, a downstream end opening 34e of the oil passages t13, t14 is formed in an upper side wall inner surface of the cylinder head cover 34 toward a valve system 56 in an upper side of the internal combustion engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil supply device for a valve train in a four-cycle internal combustion engine mounted on a vehicle with a cylinder in a largely tilted forward posture.

[0002]

2. Description of the Related Art An oil circulation system in a four-cycle internal combustion engine is a system in which not only oil from an oil tank but also oil accumulated in the lower part of a crank chamber is pumped up by an oil pump driven by rotation of a crankshaft and supplied to each necessary place. Yes, among them, the valve train is composed of the cylinder head and is located far from the crank chamber and the cylinder,
Conventionally, an oil pipe is provided along the outside of the cylinder from the crankcase side to the cylinder head side.

An example described in Japanese Patent Laid-Open No. 4-81525 will be described with reference to FIG. FIG. 11 is a right side view of the present four-cycle internal combustion engine 01 without an AC generator and the like.
A cylinder block 03 projects forward with a large forward tilt from, and a cylinder head 04 is connected to the end of the cylinder block 03.

On the side surface of the right crankcase 02, there is formed a large circular opening 05 including a crankshaft 05 arranged horizontally in the crankcase 02.
A disk-shaped base plate 06 having a through hole formed therethrough closes the circular opening 05, and an AC generator is provided outside the circular opening 05.

An oil pump 08 is constructed by being covered with the base plate 06, and a pump shaft 09 is rotatably supported below the crank shaft 05 in parallel with the crank shaft 05. The drive gear 010 fitted to the 05 and the driven gear 011 fitted to the pump shaft 09 mesh with each other to drive the oil pump 08.

Oil is supplied to various necessary parts by driving the oil pump 08, and the oil is supplied to the valve operating system through an oil cleaner 012, which extends forward below the cylinder block 03. The oil pipe 013 has a cylinder head 04
Is connected to the center of the top of the valve operating chamber 014, and oil is supplied to the center of the valve operating chamber 014 by an oil pipe 013.

[0007]

However, in the case of the 4-cycle internal combustion engine 01 in which the cylinder is largely tilted forward as described above, the oil supply to the upper valve train tends to be insufficient.

That is, the oil supply to the valve operating chamber 014 is
Since the operation is performed from the center of the valve operating system that is located above and below, the oil supplied to the valve operating chamber 014 is sufficiently supplied to the lower valve operating system, but to the upper valve operating system. It is difficult to supply oil and tends to run out of oil.

The cylinder block 03 and cylinder head
Since oil is supplied through an oil pipe 013, which is separate from 04, the number of parts increases and assembly work becomes troublesome.
The present invention has been made in view of the above points, and an object thereof is to provide an oil supply device for a four-cycle internal combustion engine capable of supplying sufficient oil to the entire valve train with a small number of parts. In point.

[0010]

In order to achieve the above object, the present invention is a four-cycle internal combustion engine in which a cylinder is mounted in a vehicle in a posture in which the cylinder is largely tilted forward. An oil passage for guiding oil supplied from an oil pump is formed on the upper side wall, and a downstream end opening of the oil passage is formed on the inner surface of the upper side wall of the cylinder head cover toward the valve operating system on the upper side of the internal combustion engine. An oil supply device for an internal combustion engine.

Since the cylinder is largely tilted forward, the valve operating system of the four-cycle internal combustion engine is positioned vertically, and the downstream end opening of the oil passage is formed toward the valve operating system above it, so that the opening is the same. The oil ejected from the first valve is first supplied to the upper valve operating system and then flows downward to reach the lower valve operating system, so that the oil can be sufficiently supplied to the entire valve operating system. Further, since the oil passage is formed in the upper side wall of the cylinder head cover, a separate oil pipe or the like is not required, the number of parts is small, and the assembling work is simplified.

In the four-cycle internal combustion engine in which the cylinder head cover is connected to the cylinder head through a gasket, the oil passage formed in the cylinder head is formed in the gasket in the oil passage of the cylinder head cover. An oil supply device for a four-cycle internal combustion engine, in which the oil holes of the gasket communicate with each other and the opening diameter of the oil holes is smaller than the inner diameters of the oil passages.

When the oil flows from the oil passage on the cylinder head side into the oil passage on the cylinder head cover side, it passes through the small-diameter oil hole of the gasket, and the oil hole serves as an orifice to increase the flow velocity, and the downstream end opening Lubricity can be further improved by increasing the momentum of injection of oil from the engine to the valve train.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view of a scooter type motorcycle 1 including a unit swing type internal combustion engine according to the present invention. The vehicle body front portion 2 and the vehicle body rear portion 3 are connected via a low floor portion 4, and the vehicle body frame forming the skeleton of the vehicle body is generally composed of a down tube 6 and a main pipe 7.

That is, a down tube 6 extends downward from the steering head 5 of the front part 2 of the vehicle body, the down tube 6 bends horizontally at the lower end and extends rearward below the floor part 4, and a pair of left and right ends at the rear end. The main pipe 7 is connected, and the main pipe 7 rises obliquely rearward from the connecting portion, is horizontally bent at a predetermined height, and extends rearward.

A fuel tank and a storage box are supported by the main pipe 7, and a seat 8 is arranged above them. On the other hand, in the front part 2 of the vehicle body, a steering wheel 5 is pivotally supported, a handle 11 is provided above the front fork 12, and a front fork 12 is extended downward and a front wheel 13 is pivotally supported at a lower end thereof.

A bracket 15 is projectingly provided on the lower end of the rising portion of the main pipe 7, and the link member 16 is attached to the bracket 15.
The swing unit 17 is swingably connected and supported via the.

A single-cylinder four-cycle internal combustion engine 30 is mounted on the front of the swing unit 17 in a posture in which the cylinder block 32 is largely tilted to a substantially horizontal state.
A hanger bracket that protrudes forward from the lower end of the unit swing case 31 corresponding to the crankcase.
The ends of 18 are connected to the link member 16 via a pivot shaft 19.

A belt type continuously variable transmission 35 is constructed from the internal combustion engine 30 to the rear, and a reduction mechanism provided at the rear portion thereof.
The rear wheel 21 is pivotally supported by 38. The rear cushion 22 is provided between the upper end of the reduction mechanism 38 and the upper bent portion of the main pipe 7.
Is interposed.

An internal combustion engine is provided above the swing unit 17.
A carburetor 24 connected to an intake pipe 23 extending from an upper portion of a cylinder head 33 of 30 and an air cleaner 25 connected to the carburetor 24 are provided. On the other hand, a main stand 26 is pivotally attached to a hanger bracket 18 projecting from the lower part of the unit swing case 31, and a belt type continuously variable transmission is provided.
A kick shaft 27 protruding from the transmission case cover 36 of 35 has a kick arm 28 to which a base end is fixed, and a kick pedal 29 is provided at a tip of the kick arm 28.

The front part 2 of the vehicle body is covered from the front and rear by the front cover 9a and the rear cover 9b from the left and right by the front lower cover 9c, and the central part of the handle 11 is covered by the handle cover 9d. The floor portion 4 is covered with side covers 9e, and the vehicle body rear portion 3 is covered with body covers 10a and tail side covers 10b from the left and right sides.

FIG. 2 shows the swing unit 17 as shown in FIG.
FIG. 2 is a cross-sectional view cut and developed along the line II-II. The unit swing case 31 is a left unit case 31 divided into left and right.
The right unit case 31R is a half of the crankcase portion, and the left unit case 31L is a long front and rear crankcase portion 31a. , A central transmission case portion 31b, and a rear reduction gear case portion 31c.

The left open surface of the left unit case 31L is covered with a transmission case cover 36, the belt type continuously variable transmission 35 is housed therein, and the right open surface of the rear reducer case portion 31c is the reducer case. Covered by 37, the speed reduction mechanism 38 is housed inside.

Crankcase portion 31a and right unit case
In a so-called crank case of 31R, a crank shaft 40 is rotatably supported by left and right main bearings 41, 41, and an AC generator 60 is provided in a right extending portion of the extending portions extending in the left and right horizontal directions.
The cam chain drive sprocket 55 and the drive pulley 76 of the belt type continuously variable transmission 35 are provided in the left extending portion.

The internal combustion engine 30 includes a piston 42 and a crankshaft 40 that reciprocate in a cylinder liner 44 of a cylinder block 32.
A connecting rod 43 is connected to the crank pin 40a of the. The four-cycle internal combustion engine 30 employs an OHC type valve system and has a cylinder head cover 34.
A valve mechanism 50 is provided inside, and a cam chain 51 for transmitting drive to the valve mechanism 50 includes a camshaft 53 and a crankshaft 40.
It is installed between the cam chain chamber 52 and
Are provided in communication with the crankcase portion 31a, the cylinder block 32, and the cylinder head 33.

That is, the cam chain 51 is provided in the cam chain chamber 52 between the driven sprocket 54 fitted to the left end of the cam shaft 53 oriented horizontally in the left and right direction and the drive sprocket 55 fitted to the crankshaft 40. Have been bridged through. An ignition plug 45 is fitted in the cylinder head 33 from the side (right side) opposite to the cam chain chamber 52 toward the combustion chamber.

As shown in FIG. 3, the cylinder head cover 34
In the valve mechanism 50, the cylinder is largely tilted forward to a state in which the cylinder is almost horizontal, so the intake valve 56 and the exhaust valve 57 are arranged above and below the cam shaft 53, and the rocker arm shaft 58 above and below. , 58 rocker arms 5 respectively
The rocker arms 59, 59 are rocked by the rotation of the cam of the cam shaft 53 so that the intake valve 56 and the exhaust valve 57 are opened and closed at a predetermined timing.

The AC generator 60 provided on the right side surface of the right unit case 31R has a bowl-shaped outer rotor 62 via an ACG boss 61 at the end of the crankshaft 30 protruding from the central cylindrical portion 31d of the right unit case 31R. A stator 64 having a stator coil 65 wound inside a magnet 63 which is fixed and is arranged on the inner peripheral surface thereof in the circumferential direction has a central cylindrical portion 31d.
It is fixed to.

A forced air cooling fan 66 is attached to the right side surface of the outer rotor 62, and a fan cover 67 covers the side of the forced air cooling fan 66, and the fan cover 67 is connected to the cylinder block 32.
A fan shroud 68 is provided so as to cover the periphery of the cylinder head 33.

On the other hand, in the crankcase portion 31a of the unit swing case 31, the cam chain chamber 52 is just the main bearing.
The cam chain chamber 52 is separated from the crank chamber by 41, and the left side wall of the cam chain chamber 52 is a partition wall 71 that further divides the belt type continuously variable transmission chamber 70 and the cam chain chamber 52 on the left side. The wall 71 is formed with a circular through hole 71a having a large-diameter flat cylindrical shape through which the crankshaft 40 penetrates.
The annular seal member 72 is press-fitted into the
The crankshaft 40 penetrates the hollow portion of 72.

The drive sprocket 55 is fitted on the crankshaft 40 between the seal member 72 and the main bearing 41,
The cam chain 51 is wound around the drive sprocket 55, and a belt type continuously variable transmission chamber is provided by a seal member 72.
70 is watertightly partitioned from the cam chain chamber 52 to prevent oil from leaking into the belt type continuously variable transmission chamber 70. A drive pulley 76 is rotatably provided on the crankshaft 40 extending through the seal member 72.

The driving pulley 76 comprises a fixed pulley half body 77 and a movable pulley half body 78, and the fixed pulley half body 77 is
It is fixed to the left end portion of the crankshaft 40 via a boss 79, the movable pulley half body 78 is spline-fitted to the crankshaft 40 on the right side thereof, and the movable pulley half body 78 rotates together with the crankshaft 40, and It can slide in and out of the stationary pulley half 77 by sliding in the axial direction.
The belt 75 is sandwiched and wrapped around.

A cam plate 80 is provided on the right side of the movable pulley half body 78 at a fixed position close to the annular seal member 72, and a slide piece 80a provided on the outer peripheral end of the cam plate 80 is provided on the movable pulley half body 78. It is slidably engaged with a cam plate sliding boss portion 78a formed on the outer peripheral end in the axial direction. The side surface of the movable pulley half body 78 on the cam plate 80 side is tapered toward the cam plate 80 side, and the dry weight roller 81 is housed inside the tapered surface sandwiched by the cam plate 80.

Therefore, when the rotational speed of the crankshaft 40 increases, the dry weight roller 81, which is located between the movable pulley half body 78 and the cam plate 80 and rotates together, moves in the centrifugal direction by the centrifugal force to move the movable pulley half body 78. Is pressed by the dry weight roller 81 and moves leftward to approach the fixed pulley half 77, and the V belt 75 sandwiched between the pulley halves 77 and 78 is moved in the centrifugal direction to be wound around. Is configured to be large.

The rear driven pulley 86 corresponding to the drive pulley 76 has a fixed pulley half body 87 fitted to an inner sleeve 89 which is rotatably supported relative to the speed reducer input shaft 92 of the speed reduction mechanism 38. The movable pulley half body 88 is fitted to the outer sleeve 90 axially slidably supported by the inner sleeve 89 on the left side of the fixed pulley half body 87, and is composed of both pulley half bodies 87, 88. Has been done. Both pulley halves 87,
The V belt 75 is clamped by 88.

A centrifugal clutch 91 is provided on the left side of the speed reducer input shaft 92 and the inner sleeve 89, and the power transmitted to the inner sleeve 89 via the V-belt 75 increases as the rotational speed increases. Are joined and transmitted to the speed reducer input shaft 92. The reduction gear mechanism 38 reduces the power transmitted to the reduction gear input shaft 92 to the output shaft 94 via the intermediate shaft 93 by gear engagement, and the output shaft 94 is the axle of the rear wheels 21 and the rear wheels. Rotate 21.

A drum brake 95 is provided on the hub portion of the rear wheel 21, and a drum brake arm 97 to which a brake cable is connected is fitted to the drum brake shaft 96,
Drum brake arm 97 when the brake cable is pulled
Swings to rotate the drum brake shaft 96 to rotate the drum brake.
95 is set to work.

The transmission case cover 36 covering the belt type continuously variable transmission chamber 70 from the left side covers from the front drive pulley 76 to the rear centrifugal clutch 91, and the kick shaft 27 rotates slightly forward from the center. The kick shaft 27 is movably supported through the drive shaft. A drive helical gear 100 is fitted to the inner end of the kick shaft 27 and is biased by a return spring 101.

A sliding shaft 102 is supported on the inner surface of the front portion of the transmission case cover 36 coaxially with the crankshaft 40 so as to be rotatable and axially slidable. The sliding shaft 102 has a driven helical gear 103. Is formed and the drive helical gear 100 is formed.
Ratchet wheel on the right end while meshing with
104 is fixed and the whole is urged to the left by the friction spring 105. On the other hand, the boss on the crankshaft 40 side
The 79 has a ratchet wheel facing the ratchet wheel 105.
79a is formed, and both can be contacted and separated by sliding of the sliding shaft 102.

Therefore, the kick pedal 29 is depressed,
When the kick shaft 27 rotates through the kick arm 28 against the return spring 101, the drive helical gear 100 rotates together with the kick shaft 27, and the driven helical gear 103 meshing with this rotates together with the sliding shaft 102. On the other hand, by sliding to the right against the friction spring 105, the ratchet wheel 105 meshes with the ratchet 79a of the boss 79 to forcibly rotate the crankshaft 40 and the internal combustion engine 30 can be started.

On the other hand, this internal combustion engine has a left unit case 31L.
The starter motor 110 is provided above the crankcase portion 31a of the starter motor 110 as shown in FIG.
Has a pinion 113 wound around a coil 112 of an inner rotor surrounded by a magnet 111 of an outer stator and protruding leftward, and a gear 113a is formed at an end of the pinion 113.

A plunging gear mechanism 115, which is sandwiched between the crankcase portion 31a and the transmission case cover 36, is provided between the starter motor 110 and the drive pulley 76 with the shaft oriented horizontally in the horizontal direction. Same dive gear mechanism
The pinion gear 113a of the starter motor 110 meshes with the input gear 116 on the right side of the 115, and the plunging gear 117 on the left side of one side
When it protrudes to the left, it meshes with the starter ring gear 77a formed on the outer peripheral edge of the stationary pulley half 77.

Therefore, when the starter motor 110 is driven, the rotation of the pinion 113 is transmitted to the input gear 116 of the plunging gear mechanism 115, and the plunging gear 117 projects to the left and engages with the starter ring gear 77a of the stationary pulley half 77. The fixed pulley half body 77 can be rotated together with the crankshaft 40 to start the internal combustion engine 30. When the starter motor 110 stops, the jump gear 117 is disengaged from the retract starter ring gear 77a.

Fixed-side pulley half 77 having a starter ring gear 77a for receiving the biting of the jump-in gear 117
Has a rubber cooling fan 118 attached to the side surface (left side surface) opposite to the side surface holding the V-belt 75 by rubber baking. The rotation of the cooling fan 118 cools the belt type continuously variable transmission 35. It

Referring to FIGS. 1 and 2, the transmission case cover 36 has a cylindrical suction duct 36a projecting from the front thereof, and a cylindrical discharge duct along the side wall at a substantially central position in the front-rear direction. 36b is formed in a diagonally vertical direction, the rear end of the bellows hose 14 is connected to the suction duct 36a, and the bellows hose 14 extends forward and is formed to project from the bent portion of the down tube 6. The front end is connected to the cylinder 6b.

Steering head 5 of down tube 6
A suction cylinder 6a is formed so as to project at a height position close to, and the inside of the down tube 6 connects the suction cylinder 6a and the discharge cylinder 6b.

Therefore, when the cooling fan 118 rotates due to the rotation of the crankshaft 40 in the belt type continuously variable transmission chamber 70,
Air is sucked from the suction tube 6a of the down tube 6, passes through the down tube 6, enters the bellows hose 14 from the discharge tube 6b, passes through the bellows hose 14, and is sucked into the belt type continuously variable transmission chamber 70 from the suction duct 36a. Being a belt type continuously variable transmission
35 is cooled and discharged from the discharge duct 36b to the outside.

In the right unit case 31R, which is the crankcase on the opposite side of the left unit case 31L in which the belt type continuously variable transmission chamber 70 is constructed as described above, the central cylindrical portion through which the crankshaft 40 penetrates as described above. 31d is formed so as to project to the right, and a circular opening 130 is formed along the central cylindrical portion 31d slightly below and below the circular opening 130, and the circular base plate 131, which is a lid member, closes the circular opening 130. Oil pump inside
140 built in.

FIG. 5 shows an AC generator of the internal combustion engine 30.
It is a right side view which removed 60 and the base plate 131. The right unit case 31R has two openings on the side wall, the central cylindrical portion 31d and the circular opening 130, and is slightly concentric with the crankshaft 40, that is, centered with the central cylindrical portion 31d, and slightly closer to the outer rotor 62 of the AC generator 60. A cylindrical rib 132 having a large outer diameter is formed so as to project, and an outer peripheral wall 133 is formed further outward.
Are installed around.

The lower portion of the cylindrical rib 132 has the circular opening.
The outer wall 133 is missing due to the circular opening 130.
It bulges somewhat downward due to. Circular opening like this
130 does not include the central cylindrical portion 31d that is a through hole of the crankshaft 40, is adjacent to the central cylindrical portion 31d, and has an outer diameter of an outer peripheral wall 133.
The size of the oil pump 140 is substantially equal to the radius of the oil pump 140 and covers the built-in oil pump 140 and its vicinity.

The circular base plate 131 that closes the circular opening 130 is fitted into the circular opening 130 with a seal ring 134 interposed therebetween, as shown in FIG. 6, and the flange portion 131a has a circular opening.
The front and rear female screw parts 130 are brought into contact with the peripheral mounting surface 130a of the 130.
Secured with bolts 135 at b. Base plate 131
The mounting boss 131b bulges on the outer surface of the
Pulsar 137 is fixed to 1b.

The pulsar 137 is an induction coil type pickup sensor, and is an outer rotor of the AC generator 60.
The reluctor 138 provided on the outer rotor 62 so as to protrude to the right so as to face the outer peripheral surface of the outer rotor 62 is detected to obtain information on the crank position and the number of revolutions. 2 in FIG.
As shown by the dotted line, the pulsar 137 is projected by the circular opening 130 at the position where the cylindrical rib 132 is missing, and the wall can be formed by just supplementing the missing part of the cylindrical rib 132.

Therefore, the air taken in from the center of the fan cover 67 by the rotation of the forced air cooling fan 66 provided on the right side surface of the outer rotor 62 of the AC generator 60 is guided to the center by the pulsar 137 together with the cylindrical rib 132 without substantially leaking. Then, the fan shroud 68 can guide the internal combustion engine 30 to the cylinder block 32 side to enhance the cooling efficiency.

On the other hand, the base plate 131 has a cylindrical projection 131c at the center of its inner surface and holds the driven gear 141 of the oil pump 140 inside. The driven gear 141 is connected to the pump shaft 142.
On the other hand, the drive gear 143 fitted to the crankshaft 40 along the main bearing 41 meshes with the driven gear 141 to transmit the rotation of the crankshaft 40 to the pump shaft 142 to transmit the oil pump 140. Is designed to drive.

As shown in FIG. 6, the oil collected at the bottom of the crankcase portion 31a passes through the oil filter 147 and
Move to the right unit case 31R through the horizontal oil passage t1, pass through the substantially vertical oil passage t2, and then the oil pump 14
It is sucked from the suction port 140a of 0, discharged from the discharge port 140b, and supplied to each lubricating system device.

As shown in FIGS. 3 and 7, the oil discharged from the discharge port 140b passes through the oil passage t3, once through the oil passage t4 between the right unit case 31R and the left unit case 31L, and then again to the right unit. It is formed toward the lower right side of the mating surface 32a (see FIG. 8) of the cylinder block 32, which passes through the oil passage t5 directed to the right horizontal direction of the case 31R and is largely inclined forward to a state close to the horizontal, with the unit cases 31L and 31R. Through the oil passage t6.

The oil from the oil passage t6 is supplied to the unit cases 31L and 31R of the cylinder block 32 as shown in FIG.
Along the cylinder hole formed in the mating surface 32a with the cylinder block
The oil passage t8, which opens at the upper right side of the cylinder hole 32 and penetrates in parallel to the axial direction of the cylinder hole, is further inserted.
As shown by the chain double-dashed line in FIG. 2, the oil passage t9, which is an extension of the oil passage t8 of the cylinder head 33, is passed through the cylinder block 32 and the cylinder head 33 to cover the cylinder head cover
Head to 34.

Referring to FIG. 3, the oil passage t9 is bifurcated into an oil passage t10 and an oil passage t11 on the way.
One of the oil passages t10 passes through an oil passage communicating with the cylinder head cover 34, and the upper rocker arm shaft.
58, the other oil passage t11 goes diagonally upward. An oil passage t20 is separately formed in the lower rocker arm shaft 58.

As described above, the oil passages t8, t9, t10, t11, and t3 are formed in the side walls of the cylinder block 32 and the cylinder head 33.
Since t20 is formed, a separate oil pipe is not required, the number of parts is small, and the assembling work is simplified.

The oil passage t11 extending obliquely upward is
As shown in FIG. 9, which is a top view of the cylinder head 33, the mating surface 33 of the cylinder head 33 with the cylinder head cover 34 is shown.
An opening 33b is formed in the upper right portion of a. cylinder head
A gasket 150 is sandwiched between the mating surfaces of the 33 and the cylinder head cover 34, and the oil passage t11 of the gasket 150 is
An oil hole 150a having a smaller diameter than the opening 33b is formed in a portion corresponding to the opening 33b.

After passing through the oil hole 150a, referring to FIG. 10 which is a bottom view of the cylinder head cover 34 and the gasket 150, it is hidden by the gasket 150 in FIG. 10 which is a groove formed in the mating surface on the cylinder head cover 34 side. As shown by the broken line, it enters the end portion 34a located at the upper right portion of the oil passage t12, and goes leftward along the upper side of the mating surface of the cylinder head cover 34 through the oil passage t12 and bends at a substantially central position on the left and right. The upper side wall 34b of the cylinder head cover 34 enters the oil passage t13 extending in the cylinder axial direction.

As shown in FIG. 3, the oil passage t13 extends substantially forward from the upper side wall 34b of the cylinder head cover 34 which is largely inclined forward to a substantially horizontal state. Of the oil passage t13 extends to a substantially middle position with the top wall 34c forming the breather chamber 34d partitioned by a large number of ribs, and is bent downward at its front end to communicate with the short oil passage t14. t
14 has an oil opening 34e on the inner surface of the upper side wall 34b. The oil opening 34e is located above and above the valve stem end portion 56a of the upper intake valve 56.

The oil passage is formed as described above, and the oil that has passed through the oil passage t11 of the cylinder head 33 passes through the oil hole 150a of the gasket 150,
The oil hole 150a is formed in the opening 33b of the oil passage t11 and the end portion 34a of the oil passage t12 on the cylinder head cover 34 side.
Since the diameter is smaller and the orifice is formed, the oil passes through the oil hole 150a, so that the flow velocity increases and enters the oil passage t12 on the cylinder head cover 34 side, and then passes through the oil passages t13 and t14, and then the cylinder head cover. 34
It jets vigorously from an oil opening 34e formed on the inner surface of the upper side wall 34b, and scatters around the valve stem end portion 56a of the intake valve 56.

Therefore, the OH in which the cylinder is largely tilted forward
In the case of the C-type 4-cycle internal combustion engine 30, the upper valve operating system, that is, the intake valve, where the oil supply tends to become insufficient
Since the oil is scattered and supplied from above to the bluub stem end portion 56a of 56, the oil is sufficiently supplied, and the oil further drops down to the camshaft 53 or the lower valve system, that is, the exhaust valve 57. Oil can be supplied to the entire valve train.

[0065]

According to the present invention, since the cylinder is largely tilted forward, the valve train of the four-cycle internal combustion engine is located vertically, and the downstream end opening of the oil passage is formed toward the valve train above it. Therefore, the oil ejected from the opening is first supplied to the upper valve operating system, and further flows downward to reach the lower valve operating system, so that the oil can be sufficiently supplied to the entire valve operating system. Further, since the oil passage is formed in the upper side wall of the cylinder head cover, a separate oil pipe or the like is not required, the number of parts is small, and the assembling work is simplified.

The oil passage formed in the cylinder head communicates with the oil passage of the cylinder head cover through the oil hole formed in the gasket, and the opening diameter of the oil hole of the gasket is made smaller than the inner diameter of both oil passages. Then, the oil hole plays a role of an orifice to increase the flow velocity, and the momentum of the injection of oil from the downstream end opening to the valve train can be increased to further improve the lubricity.

[Brief description of the drawings]

FIG. 1 is an overall side view of a scooter type motorcycle according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the internal combustion engine of the scooter type motorcycle taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a right side view of the internal combustion engine with an AC generator and a base plate removed.

6 is a cross-sectional view taken along line VI-VI in FIG.

7 is a cross-sectional view taken along the line VII-VII in FIG.

FIG. 8 is a view of the cylinder block viewed from the arrow VIII in FIG.

9 is a top view of the cylinder head divided along line IX-IX in FIG.

10 is a bottom view of the cylinder head cover divided along the line XX in FIG.

FIG. 11 is a right side view of a conventional four-cycle internal combustion engine with an AC generator and the like omitted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle, 2 ... Vehicle body front part, 3 ... Vehicle body rear part, 4 ... Floor part, 5 ... Steering head, 6 ... Down tube, 7 ... Main pipe, 8 ... Seat, 9a ... Front cover, 9b ... Rear cover , 9c ... front lower cover, 9d ... handle cover, 9e ... side cover,
10a ... Body cover, 10b ... Tail side cover, 11 ...
Handle, 12 ... Front fork, 13 ... Front wheel, 14 ... Bellows hose, 15 ... Bracket, 16 ... Link member, 17 ... Swing unit, 18 ... Hanger bracket, 19 ... Pivot shaft, 21 ... Rear wheel, 22 ... Rear cushion, 23 ... intake pipe, 24 ...
Vaporizer, 25 ... Air cleaner, 26 ... Main stand, 27 ...
Kick axis, 28 ... Kick arm, 29 ... Kick pedal, 30 ...
Internal combustion engine, 31 ... Unit swing case, 32 ... Cylinder block, 33 ... Cylinder head, 34 ... Cylinder head cover, 35 ... Belt type continuously variable transmission, 36 ... Transmission cover case, 37 ... Reduction gear case, 38 ... Reduction gear mechanism, 40 ... Crankshaft, 41 ... Main bearing, 42 ... Piston, 43 ... Connecting rod, 44 ... Cylinder liner, 45 ... Spark plug, 50 ... Valve mechanism, 51 ... Cam chain, 52 ... Cam chain chamber, 53 ...
Camshaft, 54 ... Driven sprocket, 55 ... Drive sprocket, 56 ... Intake valve, 57 ... Exhaust valve, 58 ... Rocker arm shaft, 59 ... Rocker arm, 60 ... AC generator, 61 ... ACG boss, 62 ... Outer rotor, 63 ... Magnet, 64 ... Stator, 65 ... Stator core, 66 ... Fan, 67
... fan cover, 68 ... fan shroud, 70 ... belt type unauthorized transmission chamber, 71 ... partition wall, 72 ... seal member, 73 ... rubber member, 74a ... steel plate, 74b ... presser ring, 75 ... V belt,
76 ... Drive pulley, 77 ... Fixed pulley half, 78 ... Movable pulley half, 79 ... Boss, 80 ... Cam plate, 81 ... Dry weight roller, 86 ... Driven pulley, 87 ... Fixed pulley half, 88 … Movable pulley half, 89… Inner sleeve, 90…
Outer sleeve, 91 ... Centrifugal clutch, 92 ... Reduction gear input shaft, 93 ... Intermediate shaft, 94 ... Output shaft, 95 ... Drum brake, 96
… Drum brake shaft, 97… Drum brake arm, 100
… Drive helical gear, 101… Return spring, 102
... Sliding shaft, 103 ... Driven helical gear, 104 ... Ratchet wheel, 105 ... Friction spring, 110 ... Starter motor, 111 ... Magnet, 112 ... Coil, 113 ... Pinion, 115 ... Plunge gear mechanism, 116 ... Input gear, 117 ...
Plunge gear, 118 ... Cooling fan, 130 ... Circular opening, 131
... Base plate, 132 ... Cylindrical rib, 133 ... Outer peripheral wall, 134 ...
Seal ring, 135… Bolt, 137… Pulsar, 138…
Reductor, 140 ... Oil pump, 141 ... Driven gear, 14
2 ... Pump shaft, 143 ... Drive gear, 147 ... Oil filter, 150 ... Gasket, t1, t2, t3, t4, t5
, T6, t7, t8, t9, t10, t11, t12, t1
3, t14, t20 ... Oil passage.

Claims (2)

[Claims] 1. In a four-cycle internal combustion engine in which a cylinder is mounted in a vehicle in a largely tilted posture, an oil passage for guiding oil supplied from an oil pump is provided on an upper side wall of a cylinder head cover, which is largely tilted like the cylinder. An oil supply device for a four-cycle internal combustion engine, characterized in that a downstream end opening of the oil passage is formed on an inner surface of an upper wall of the cylinder head cover toward an upper valve operating system of the internal combustion engine. 2. The four-cycle internal combustion engine in which the cylinder head cover is connected to the cylinder head through a gasket, wherein an oil passage formed in the cylinder head is provided in the oil passage of the cylinder head cover in the gasket. The oil supply device for a four-cycle internal combustion engine according to claim 1, wherein the oil holes communicate with each other through the formed oil holes, and the opening diameter of the oil holes of the gasket is smaller than the inner diameters of the oil passages.