JPH05156904A - Valve system lubricating device for four-cycle engine - Google Patents

Abstract

PURPOSE:To improve lubrication of a cam and a rocker arm by forming a rocker shaft communicating hole which communicates a space inside a rocker shaft with an oil reservoir part, and forming a rocker arm oil passage which communicates a journal part of the rocker arm with the oil reservoir part. CONSTITUTION:A cam shaft 29 on which cams 26A and 26B are integrated and rocker shafts 38A, 38B which journal rocker arms 27A, 27B are provided on a cylinder head 13. A rocker shaft oil passage for flowing lubricating oil is formed inside the oppositional rocker shaft 38 arranged separately from a ground horizontal line S, among the rocker shafts. An oil reservoir part 58 for filling lubricating oil is formed inside a journal part 57 of the rocker arm 27A which is journalled by the oppositional rocker shaft 38A. A through-hole 60 communicated with the oil reservoir part 58 is formed in the oppositional rocker shaft 38A. An oil passage 61A communicated with the oil reservoir part 58 is formed in the journal part 57 of the rocker arm 27A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve train lubrication device for a four-cycle engine in which a cylinder block and a cylinder head member are arranged so as to be inclined with respect to a crankcase.

[0002]

2. Description of the Related Art A four-cycle engine has a valve mechanism.
In this valve operating mechanism, a rocker shaft is inserted into a rocker shaft insertion hole provided in a cylinder head, a rocker arm is swingably supported on this rocker shaft, and the rocker arm is swung by the rotation of a cam of a cam shaft to intake air. The valve and the exhaust valve are driven to open and close the intake hole and the exhaust hole at a predetermined timing.

In the above valve operating mechanism, the oil pump guides the lubricating oil to the main oil passage in the camshaft,
Lubricating oil is guided from the sub oil passage communicating with the main oil passage to the cam surface to lubricate the cam slipper portion of the rocker arm and the cam. Further, a part of the lubricating oil in the main oil passage flows to the cam chain side to lubricate the thrust receiving portions of the cam chain and the cam shaft.

[0004]

However, in the lubrication of the rocker arm and the cam as described above, when the camshaft rotates at high speed, the lubricating oil from the sub oil passage is vigorously scattered by the centrifugal force in the diameter direction. The lubricating oil may not adhere to the cam surface sufficiently. Further, when the camshaft rotates at a low speed, the amount of oil flowing from the main oil passage toward the cam chain tends to increase. In any of these cases, the lubrication of the cam and the rocker arm may be insufficient.

The present invention has been made in consideration of the above circumstances, and provides a valve operating mechanism for a four-cycle engine in which the cylinder block and the cylinder head member are installed so as to be inclined to be substantially horizontal with respect to the crankcase. An object of the present invention is to provide a valve train lubrication device for a four-cycle engine that can be satisfactorily lubricated.

[0006]

According to the present invention, a cylinder block and a cylinder head member are arranged substantially horizontally with respect to a crankcase, and a camshaft integrally formed with a cam and a rocker arm are swingable on the cylinder head member. A rocker shaft that is pivotally supported is installed at one end, one end of the rocker arm contacts the intake / exhaust valve, and the cam slipper part at the other end contacts the cam, and the intake / exhaust valve is activated by the rotation of this cam. In a four-cycle engine equipped with a valve mechanism that operates, a rocker shaft oil passage for flowing lubricating oil is formed inside a detached rocker shaft installed at a position apart from the ground horizontal line in the rocker shaft, and the detached rocker shaft has An oil reservoir that fills lubricating oil is formed inside the journal of the rocker arm that is pivotally supported. A rocker shaft communication hole that communicates the inside of the rocker shaft with the oil storage portion is formed in the detached rocker shaft, and the journal portion of the rocker arm pivotally supported by the detached rocker shaft has the oil storage portion. A rocker arm oil passage that communicates is formed.

[0007]

Therefore, according to the four-cycle engine valve mechanism lubricating device of the present invention, the lubricating oil is guided from the rocker shaft oil passage through the rocker shaft communication hole to the oil storage portion of the journal portion of the rocker arm. The lubricating oil is then allowed to flow down from the rocker arm oil passage to the cam and the cam slipper portion of the rocker arm. As a result, it is possible to satisfactorily lubricate the cam and the cam slipper part of the rocker arm together with the lubricating oil guided from the camshaft oil passage in the camshaft to the cam.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a four-cycle engine to which an embodiment of a valve mechanism lubricating device for a four-cycle engine according to the present invention is applied, and is a sectional view taken along the line I--I of FIG.
2 is a side view of the four-cycle engine of FIG. 1, and FIG. 2 is a side view of a business bike type motorcycle equipped with the engine of FIG.

The business motorcycle type motorcycle shown in FIG. 3 has a front wheel 2 pivotally supported by a front fork 1 in front of the vehicle and a rear wheel 4 driven by a 4-cycle engine 3 in rear of the vehicle. The rider straddling the upper seat 5 operates the handle 6 to operate. The 4-cycle engine 3 is mounted in the lower center of the body frame 7, and the seat 5 is installed in the upper center of the body frame 7.

As shown in FIG. 3, the four-cycle engine 3 houses a crankshaft 9 and a crankcase 9 for accommodating a transmission (not shown), and a piston 10 (FIGS. 4 and 5) installed in the crankcase 9. Cylinder block 11 and this cylinder block 1
1 and the combustion chamber 12 between the piston 10 and the piston 10 (see FIG.
And a cylinder head 13 constituting FIG. 4).

The reciprocating motion of the piston 10 due to the explosion of the air-fuel mixture in the combustion chamber 12 is converted into rotary motion by the crankshaft 8 via the connecting rod 14, and this rotary motion is decelerated by a transmission (not shown). It is transmitted to the drive sprocket 15 shown in FIG. A drive chain (not shown) is provided between the drive sprocket 15 and the driven sprocket (not shown) on the rear wheel 4 side.
Is wound around and the rotational force of the engine is transmitted to the rear wheel 4. Reference numeral 16 in FIG. 3 is a gear shift lever that selects a transmission gear of the transmission.

As shown in FIG. 1, the cylinder head 13 of the four-cycle engine 3 is provided with an intake hole 17 and an exhaust hole 18 in the combustion chamber 12 one by one. An intake port 19 and an exhaust port 20 are formed in communication with each other. Intake hole 17, exhaust hole 1
8, an intake valve 21 and an exhaust valve 22 are arranged, and an intake manifold 23 and an exhaust manifold 24 are respectively provided in the intake port 19 and the exhaust port 20.
Are connected as shown in FIG.

The intake manifold 23 includes a carburetor 25.
The air-fuel mixture produced by the exhaust manifold 24 is introduced into the combustion chamber 12 when the intake valve 21 is opened.
Discharges the waste gas generated in the combustion chamber 12 to the outside of the engine via a muffler (not shown) when the exhaust valve 22 is opened. Combustion of the air-fuel mixture in the combustion chamber 12
This is done by igniting the sparks of the spark plug 26 shown in FIG.

The intake valve 21 and the exhaust valve 22
The opening / closing operation is performed by a valve mechanism including the intake cam 26A and the exhaust cam 26B, the intake rocker arm 27A and the exhaust rocker arm 27B, the valve spring 28, and the like shown in FIGS.

The intake cam 26A and the exhaust cam 26B are
Both of them are integrally formed adjacent to one cam shaft 29, and are rotatably supported at the substantially center of the cylinder head 13. As shown in FIG. 4, a sprocket mounting flange 30 is rotatably connected to one end of the cam shaft 29, and a cam chain driven sprocket 31 and a flywheel 32 are fixed to the sprocket mounting flange 30 with bolts or the like. The cam chain 34 is wound around the cam chain driven sprocket 31 and the cam chain drive sprocket 33 of the crankshaft 8, and the rotation of the crankshaft 8 is transmitted to the camshaft 29. At this time, 2 of the crankshaft 8
The diameters of the cam chain drive sprocket 33 and the cam chain driven sprocket 31 are set so that the cam shaft 29 rotates once per rotation.

Further, the intake valve 21 and the exhaust valve 2
2 is a valve guide 3 fixed to the cylinder head 13.
5 is inserted. The valve spring 28 is interposed in a compressed state between a spring retainer 36 installed on the head portion of the valve stem and the valve guide 35 or the cylinder head 13, and the valve faces of the intake valve 21 and the exhaust valve 22 are respectively intake valves. The hole 17 and the exhaust hole 18 are urged to be closed.

As shown in FIG. 5, two intake side rocker shaft insertion holes 37A and exhaust side rocker shaft insertion holes 37B are formed in the cylinder head 13, and these intake side rocker shaft insertion holes 37A are connected to the intake side rocker shafts. The shaft 38A has an exhaust side rocker shaft insertion hole 37B.
The exhaust side rocker shafts 38B are fitted into the respective parts.
The intake rocker arm 27A and the exhaust rocker arm 27B
Are swingably supported by the intake-side rocker shaft 38A and the exhaust-side rocker shaft 38B at their longitudinal center positions, respectively. The intake cam 26 is attached to one end of each of the intake rocker arm 27A and the exhaust rocker arm 27B.
A cam slipper portion 39 that is in contact with each of A and the exhaust cam 26B is fixed. In addition, intake rocker arm 27
A, the intake valve 2 at the other end of the exhaust rocker arm 27B
1. The adjusting screw 40 that contacts the valve stem head of the exhaust valve 22 and adjusts the tappet amount is screwed.

The intake rocker arm 27A includes an intake cam 26.
The intake valve 21 is operated with the valve lift amount and valve timing of A to open and close the intake hole 17. The exhaust rocker arm 27B operates the exhaust valve 22 according to the valve lift amount and valve timing of the exhaust cam 26B,
The exhaust hole 18 is opened and closed.

When assembling the valve operating device as described above,
The intake valve 21, the exhaust valve 22, the valve spring 28, the intake rocker arm 27A, and the exhaust rocker arm 27B are incorporated from an inspection window 41 opened in front of and behind the cylinder head 13. These inspection windows 41 are closed by an inspection cap 42 shown in FIG. Further, the cam shaft 29, the cam chain driven sprocket 31 and the like shown in FIG. 4 are incorporated through an assembling window 43 opened on the left side of the cylinder head 13. The built-in window 43 is closed by a cylinder head L cover 44. A cylinder head R cover 45, which is also shown in FIG. 6, is bolted to the cylinder head 13 at a position opposite to the cylinder head L cover 44.

As shown in FIGS. 1 and 3, the cylinder block 11 is installed in the crankcase 9 while tilting forward until it becomes substantially horizontal to the surface horizontal line S, and the cylinder head 13 is mounted on the cylinder block 11. It is installed. Therefore, the exhaust side rocker shaft 38B shown in FIG. 1 is an approaching rocker shaft installed at a position close to the surface horizon S, and the intake side rocker shaft 38A is an isolated rocker shaft installed at a position away from the surface horizon S. is there.

Further, four stud bolts 46 (FIG. 5) are planted in the crankcase 9. These stud bolts 46 penetrate the cylinder block 11 and the cylinder head 13, and a nut 47 (FIG. 4) is screwed into the tip thereof,
These cylinder block 11 and cylinder head 13
Is fixed to the crankcase 9. As shown in FIG. 5, one of these four stud bolts 46 penetrates the exhaust side rocker shaft insertion hole 37B. The intake side rocker shaft 38A has a length that extends over substantially the entire length of the intake side rocker shaft insertion hole 37A, and the exhaust side rocker shaft 38B is formed shorter than the total length of the exhaust side rocker shaft insertion hole 37B. The stud bolt 46 penetrating the inside of the exhaust side rocker shaft insertion hole 37B is attached to the exhaust side rocker shaft 38.
This exhaust side rocker shaft 38B is brought into contact with the end portion of B
To position.

A gap 49 between the stud bolt insertion hole 48 of the stud bolt 46 and the stud bolt 46, which penetrates the exhaust side rocker shaft insertion hole 37B, constitutes a lubricating oil passage. An oil pump (not shown) driven by the crankshaft 8 guides the lubricating oil into the gap 49 and further into the exhaust side rocker shaft insertion hole 37B.

The cylinder head R cover 45 has a cylinder head RNo. 1 cover element 45A and cylinder head RNo. The two cover elements 45B are overlapped and configured. Cylinder head RNo. A maze-shaped cooling oil passage 50 is formed in the 1 cover element 45B to cool the lubricating oil. In addition, the cylinder head RNo. 2 In the cover element 45B, the guide oil passage 51
A, 51B and 51C are formed. Guide oil passage 51A
Guides the lubricating oil in the exhaust side rocker shaft insertion hole 37B into the cooling oil passage 50. The guide oil passage 51B guides the lubricating oil cooled in the cooling oil passage 50 to the camshaft main oil passage 53 described later. In addition, the guide oil passage 51C
Means the lubricating oil cooled in the cooling oil passage 50 as the rocker shaft oil passage for the intake side rocker shaft 38A.
Lead in.

As shown in FIG. 4, the cylinder head 1
The camshaft 29 arranged at No. 3 is rotatably supported by a bearing 52 and has a camshaft main oil passage 53 inside. This camshaft main oil passage 53 extends over the entire length of the camshaft 29,
It communicates with the oil outflow hole 54 of the flywheel 32. The camshaft 29 is further communicated with the camshaft main oil passage 53, and has an intake cam 26A and an exhaust cam 26B.
The camshaft sub-oil passage 55 leading to the cam surface is communicated. The lubricating oil guided from the guide oil passage 51B to the camshaft main oil passage 53 is supplied from the camshaft sub oil passage 55 to the intake cam 26A and the exhaust cam 26.
Guided to both cam surfaces of B, the cam surface of the intake cam 26A and the cam slipper portion 39 of the intake rocker arm 27A, and the cam surface of the exhaust cam 26B and the cam slipper portion 39 of the exhaust rocker arm 27B are lubricated well. ..

The lubricating oil in the camshaft main oil passage 53 further passes through the oil outflow hole 54, flows toward the outer circumference due to the action of centrifugal force, and scatters in the cam chain chamber 56 to lubricate the cam chain 34. Further, the lubricating oil scattered in the cam chain chamber 56 is
The sliding contact portion 56A between the sprocket mounting flange 30 and the cylinder head 13 is lubricated with the lubricating oil after lubrication.

On the other hand, as shown in FIG. 5, the lubricating portion 57 of the intake rocker arm 27A pivotally supported by the intake rocker shaft 38A is provided with an oil storage portion 58 at a position in sliding contact with the intake rocker shaft 38A. .. As shown in FIGS. 9A and 9B, the cylinder head RNo. 1 cover element 45
An oil inflow slit 59 is formed at the end contacting the A guide oil passage 51C. This oil inflow slit 59 is
The cylinder head RNo. Is provided at four circumferentially equidistant positions at the end of the intake-side rocker shaft 38A. The lubricating oil from the guide oil passage 51C of the 1 cover element 45A is guided into the intake side rocker shaft 38A.

Further, as shown in FIGS. 1, 5 and 8, the intake side rocker shaft 38A is provided with a rocker shaft communication hole 60 at a position corresponding to the oil storage portion 58 of the intake rocker arm 27A. The rocker shaft communication hole 60 communicates the inside of the intake side rocker shaft 38A with the oil storage portion 58, guides the lubricating oil guided into the intake side rocker shaft 38A to the oil storage portion 58 of the intake rocker arm 27A, and the intake side. The rocker shaft 38A and the journal portion 57 of the intake rocker arm 27A are lubricated.

A rocker arm oil passage 61A is formed in the journal portion 57 of the intake rocker arm 27A, as shown in FIGS. 1, 5, 7, and 8. The rocker arm oil passage 61A communicates with the oil storage portion 58 and is formed toward the contact portion between the intake cam 26A and the cam slipper portion 39 of the intake rocker arm 27A. Therefore, the intake rocker arm 2 is held in the oil reservoir 58.
The lubricating oil that lubricates the journal portion 57 of 7A is then discharged from the rocker arm oil passage 61A of the intake rocker arm 27A. At this time, the cylinder block 11
Since the cylinder head 13 is positioned substantially horizontally and the intake rocker arm 27A is swinging, the lubricating oil discharged from the rocker arm oil passage 61A of the intake rocker arm 27A is sucked into the intake cam 26A, the exhaust cam 26B, and the intake rocker arm 27A. Exhaust rocker arm 27B
It is sprayed from above onto the cam slipper part 39. And
The lubricating oil is guided to a wedge-shaped portion 62 formed by the cam slipper portion of the intake cam 26A and the intake cam 26A, and a wedge-shaped portion formed by the exhaust cam 26B and the cam slipper portion 39 of the exhaust rocker arm 27B. The intake cam 26A and the cam slipper portion 39 of the intake rocker arm 27A, and the exhaust cam 26B and the exhaust rocker arm 27.
Lubrication with the B cam slipper portion 39 is satisfactorily performed.

Further, in the journal portion 57 of the exhaust rocker arm 27B as well as the intake cam 26A, the oil storage portion 5 is provided.
8 is formed, and the exhaust cam 26B is connected to the exhaust rocker arm 27.
A rocker arm oil passage 61B is formed toward the contact portion of B with the cam slipper portion 39. Cylinder block 11
Since the cylinder head 13 and the cylinder head 13 are positioned substantially horizontally, the camshaft sub oil passage 5 of the camshaft 29
Lubricating oil flowing out from No. 5 is exhaust rocker arm 27B.
From the rocker arm oil passage 61B into the oil storage portion 58 of the exhaust rocker arm 27B, and the journal portion 57 of the exhaust rocker arm 27B is satisfactorily lubricated. Therefore, the exhaust side rocker shaft 38B has a rocker shaft communication hole 60 like the intake side rocker shaft 38A.
Is not formed.

Next, the function and effect will be described.

Lubricating oil pressure-fed into the gap 49 between the stud bolt 46 and the stud bolt insertion hole 48 by an oil pump (not shown) causes the cylinder head RNo. 1 cover element 45A through the guide oil passage 51A to the cylinder head RNo. 2 Cover element 45B cooling oil passage 50
To be cooled, and part of the cylinder head RNo. The oil is guided from the guide oil passage 51B of the first cover element 45A to the camshaft main oil passage 53 of the camshaft 29. The rest of the lubricating oil in the cooling oil passage 50 is the cylinder head RNo. Guide oil passage 51 of 1 cover element 45A
It is guided from C through the oil inflow slit 59 into the intake side rocker shaft 38A.

The lubricating oil guided to the camshaft main oil passage 53 is discharged from the camshaft sub oil passage 55 to form the intake cam 26A and the intake rocker arm 27A.
Of the cam slipper portion 39, and the exhaust cam 26B and the cam slipper portion 39 of the exhaust rocker arm 27B are lubricated, and the cam chain 34 is discharged from the oil outflow hole 54.
Lubricate etc.

The lubricating oil guided in the intake rocker shaft 38A is guided to the oil reservoir 58 of the intake rocker arm 27A to lubricate the journal portion 57 of the intake rocker arm 27A, and after the lubrication, the intake rocker arm 27A. Out of the rocker arm oil passage 61A to lubricate the intake cam 26A and the cam slipper portion 39 of the intake rocker arm 27A, and the exhaust cam 26B and the cam slipper portion 39 of the exhaust rocker arm 27B.

In this way, the intake cam 26A, the cam slipper portion 39 of the intake rocker arm 27A, and the exhaust cam 26 are provided.
B and the cam slipper portion 39 of the exhaust rocker arm 27B are the camshaft sub oil passage 5 of the camshaft 29.
5 and the wedge-shaped portion 6 discharged from the rocker arm oil passage 61A of the intake cam 27A.
Since it is lubricated with the lubricating oil accumulated in 2, the lubrication is performed extremely well.

Further, the lubricating oil discharged from the rocker arm oil passage 61A of the intake rocker arm 27A utilizes the fact that the cylinder block 11 and the cylinder head 13 are arranged substantially horizontally with respect to the crankcase 9 and the exhaust cam 26A and the exhaust gas. Since the structure is such that it is sprinkled onto the cam 26B from above, an oil passage for lubricating the intake cam 26A and the cam slipper part 39 of the intake rocker arm 27A, and the exhaust cam 26B and the cam slipper part 39 of the exhaust rocker arm 27B are configured with a simple structure. it can. For this reason,
It is possible to suppress the increase in cost, and also for already sold vehicles,
Minimum number of parts (cylinder head 13, cylinder head R
The cover 45, the intake rocker shaft 38A, the intake rocker arm 27A, etc.) can be replaced. Furthermore, it is easy to assemble and maintain.

Although the intake side rocker shaft 38A is provided with the oil inflow slit 59 in the above embodiment, the end of the intake side rocker shaft 63 as shown in FIGS. 10 (A) and 10 (B) is described. Oil inflow slit 5
9 is not formed, the end of the cylinder head RNo. 1 Cylinder head RNo. The lubricating oil may be guided from the guide oil passage 51C of the 1 cover element 45A into the intake side rocker shaft 63.

FIG. 11, FIG. 12 and FIG. 13 are views showing the intake rocker arm in the second embodiment of the present invention.

In the intake rocker arm 64, instead of the rocker arm oil passage 61A of the intake rocker arm 27A, oil outflow notches 66 are formed at both ends of the journal portion 65. An oil storage portion 58 is also formed in the journal portion 65, and the oil outflow cutout portion 66 communicates with the oil storage portion 58. Intake side rocker shaft 38
The lubricating oil in A reaches the oil reservoir 58 from the rocker shaft communication hole 60 and lubricates the journal portion 65,
It flows out from the oil outflow notch 66. Further, the lubricating oil that flows through the oil outflow notch 66 in the gap between the intake side rocker shaft 38A and the journal 67 of the cylinder head 13 as shown by the chain double-dashed line in FIG. 13 is also discharged. Lubricating oil from the oil outflow notch 66 provides good lubrication between the intake cam 26A and the cam slipper part 39 of the intake rocker arm 27A, and the exhaust cam 26B and the cam slipper part 39 of the exhaust rocker arm 27B.

In both of the above embodiments, the case of the forward leaning engine in which the cylinder block 11 and the cylinder head 13 are leaning forward until the cylinder block 11 and the cylinder head 13 are substantially horizontal is described. However, in the V type engine, one cylinder block and the cylinder head are It can also be applied to engines that are tilted until they are approximately horizontal, and horizontally opposed engines.

[0041]

As described above, according to the four-cycle engine valve mechanism lubrication apparatus of the present invention, the four-cycle engine in which the cylinder block and the cylinder head member are arranged substantially horizontally with respect to the crankcase is operated. In the rocker shaft of the valve mechanism, a rocker shaft oil passage for flowing lubricating oil is formed inside the detached rocker shaft installed at a position away from the horizontal surface of the ground, and inside the journal portion of the rocker arm pivotally supported by the detached rocker shaft. An oil reservoir for filling lubricating oil is formed, and a rocker shaft communication hole that communicates the inside of the rocker shaft and the oil reservoir is formed in the detached rocker shaft, and a rocker arm pivotally supported by the detached rocker shaft. The journal section of the Since Muoiru passage is formed, lubricating oil after lubricating the rocker arm journal portion is discharged from the rocker arm oil passage can be satisfactorily lubricated with the cam slipper portion of the cam and the rocker arm.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along line I-I of FIG. 4, showing a four-cycle engine to which an embodiment of a valve train lubrication device for a four-cycle engine according to the present invention is applied.

FIG. 2 is a side view of a business bike type motorcycle equipped with the engine of FIG.

3 is a side view of the 4-cycle engine of FIG. 1. FIG.

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

5 is a cross-sectional view taken along the line VV of FIG.

6 is a view on arrow VI of FIG.

FIG. 7 is a front view of the intake-side rocker arm shown in FIG.

8 is a sectional view taken along the line VIII-VIII in FIG.

9A is a partially cutaway side view of the intake side rocker shaft of FIG. 1, and FIG. 9B is a view taken along the line IXB of FIG. 9A.

10A is a partial cross-sectional side view showing a modified example of the intake side rocker shaft shown in FIG. 9A, and FIG.
FIG.

FIG. 11 is a plan view showing an intake side rocker arm according to a second embodiment of the present invention.

12 is a front view of the intake side rocker arm of FIG. 11. FIG.

13 is a cross-sectional view taken along the line XIII-XIII in FIG. 12 showing the cylinder head and the rocker shaft.

[Explanation of symbols]

 3 4 cycle engine 9 Crank case 11 Cylinder block 13 Cylinder head 21 Intake valve 22 Exhaust valve 26A Intake cam 26B Exhaust cam 27A Intake rocker arm 27B Exhaust rocker arm 29 Camshaft 37A Intake side rocker shaft insertion hole 37B Exhaust side rocker shaft insertion hole 38A Intake Side rocker shaft 39 Cam slipper part 57 Journal part 58 Oil storage part 60 Rocker shaft communication hole 61 Rocker arm oil passage S Ground horizontal line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location F01M 9/10 B 8109-3G G 8109-3G F02B 67/00 Q 9247-3G

Claims (1)

[Claims] 1. A cylinder block and a cylinder head member are arranged substantially horizontally with respect to a crankcase, and a camshaft integrally formed with a cam and a rocker shaft for rockably supporting a rocker arm are mounted on the cylinder head member. The rocker arm is installed, and one end of the rocker arm comes into contact with the intake / exhaust valve, and the cam slipper portion at the other end comes into contact with the cam, and a rotation mechanism is provided to operate the intake / exhaust valve. In a cycle engine, a rocker shaft oil passage for flowing lubricating oil is formed inside a detached rocker shaft installed at a position apart from the ground horizontal line in the rocker shaft, and a journal portion of a rocker arm pivotally supported by the detached rocker shaft. An oil reservoir that fills lubricating oil is formed inside, and the separation rocker shaft is A rocker shaft communication hole that connects the inside of the rocker shaft and the oil storage portion is formed, and a rocker arm oil passage that communicates with the oil storage portion is formed in the journal portion of the rocker arm pivotally supported by the detached rocker shaft. A valve mechanism lubrication device for a four-cycle engine, which is formed.