JPH05156917A - Four-cycle engine - Google Patents

Abstract

PURPOSE:To perform satisfactorily lubrication between a cam of a cam shaft and a cam slipper part of a rocker arm by forming oil passages for flowing lubricating oil into a cam shaft of a valve system, and providing oil guide parts extending in a direction of the cam between the cam shaft and a cylinder head member. CONSTITUTION:Oil passages 47, 50 are formed for flowing lubricating oil into a cam shaft 29 of a valve system. Oil guide parts 51, 52 are extending in a direction of the cam are arranged between the cam shaft and a cylinder head member 13. The lubricating oil scattered from the oil passages is struck against the oil guide parts 51, 52 and introduced to the cam. A cam shaft driving chamber which houses cam shaft driving systems 31, 34 is communicated with a rocker arm housing chamber 59 which is provided on the cylinder head member 13 and houses rocker arms 27A, 27B. A breezer chamber is formed on a cover member separate from a ground horizontal line, among tappet adjusting cover members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-cycle engine having an improved lubrication structure and breather chamber for a valve train.

[0002]

2. Description of the Related Art A four-cycle engine has a valve operating device. This valve operating device inserts a rocker shaft into a rocker shaft insertion hole provided in a cylinder head, and a rocker arm is swingably supported by the rocker shaft. The rocker arm is rocked by the rotation of the cam of the cam shaft to drive the intake valve and the exhaust valve, and the intake hole and the exhaust hole are opened and closed at a predetermined timing.

In the above valve operating system, 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 surfaces of the cam chain and the cam shaft.

On the other hand, in a four-cycle engine, a breather union is generally driven into a crankcase, and a breather hose is connected to this union to circulate blow-by gas leaking into the crankcase to an air cleaner to reduce the internal pressure of the crankcase. There is something like this.

[0005]

However, in the lubrication of the rocker arm and the cam as described above, when the cam shaft rotates at high speed, the lubricating oil from the sub oil passage is vigorously scattered in the cam diameter direction by the centrifugal force. The lubricating oil may not adhere sufficiently to the cam surface.
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 between the cam and the cam slipper portion of the rocker arm may be insufficient.

On the other hand, in the case where the blow-by gas in the crank case is directly discharged as described above, the blow-by gas in the crank case receives the most pumping pressure in the crank case. May be discharged more than necessary. Further, since a large amount of lubricating oil is stored in the crankcase, the lubricating oil in the crankcase may flow out of the engine through the breather hose when the vehicle falls.

In view of the above-mentioned circumstances, the invention according to claim 1 provides a four-cycle engine which can favorably lubricate the cam of the camshaft and the cam slipper of the rocker arm in the valve train. It is an object of the present invention to provide a four-cycle engine capable of preventing unnecessary blow-by gas from being blown out from the breather chamber.

[0008]

According to a first aspect of the present invention, a cylinder head member is provided with a cam shaft integrally formed with a cam and a rocker shaft pivotably supporting a rocker arm. A four-cycle engine equipped with a valve operating device for operating the intake / exhaust valve by the rotation of the cam with one end of the valve contacting the intake / exhaust valve and the other end of the cam slipper contacting the cam. An oil passage through which lubricating oil flows is formed inside the camshaft, and an oil guide portion extending in the cam direction is arranged between the camshaft and the cylinder head member to prevent the lubricating oil scattered from the oil passage. It is configured so as to collide with the oil guide portion and be guided to the cam.

According to a second aspect of the present invention, a cylinder block is installed in a crankcase accommodating a crankshaft in such a manner that the cylinder block is tilted forward, and a cam is integrally formed with a cylinder head member installed in the cylinder block. And a rocker shaft that swingably supports the rocker arm is installed, one end of the rocker arm contacts the intake / exhaust valve, and the cam slipper part at the other end contacts the cam,
In a four-cycle engine provided with a valve operating device that operates the intake and exhaust valves by the rotation of the cam, a camshaft drive system that rotates the camshaft by the rotational force of the crankshaft includes the crankcase, the cylinder block, and A rocker arm housing chamber, which is housed in a camshaft driving chamber formed over the cylinder head member and housing the rocker arm, is formed in communication with the camshaft driving chamber. The intake / exhaust valve and the rocker arm face the rocker arm housing chamber. Among the tappet adjusting cover members for adjusting the tappets, the breather chamber is formed in the cover member remote from the ground horizontal line.

[0010]

Therefore, according to the four-cycle engine of the first aspect of the invention, the lubricating oil scattered from the oil passage of the camshaft collides with the oil guide portion and is guided to the cam. Sufficient lubricating oil is introduced to the cam slipper part and the cam of the rocker arm without being scattered. Therefore, it is possible to satisfactorily lubricate the cam and the cam slipper part.

According to the four-cycle engine of the second aspect of the present invention, the cover member of the tappet adjusting cover member, which is separated from the horizontal surface of the ground, is a place where pressure fluctuation in the crankcase is less likely to occur. Therefore, if the breather chamber is installed in the tappet adjusting cover member at this position, the influence of pressure fluctuation due to the pumping of the piston is minimized, and blow-by gas does not blow out more than necessary from the breather chamber.

[0012]

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

FIG. 1 shows an embodiment of a four-cycle engine according to the present invention, which is a partially enlarged view of FIG. 4, and FIG.
2 is an overall side view of the engine of FIG. 2, and FIG. 2 is a side view of a business bike type motorcycle equipped with the engine of FIG.

In the business motorcycle type motorcycle shown in FIG. 3, a front wheel 2 pivotally supported by a front fork 1 is arranged in front of the vehicle, and a rear wheel 4 driven by a 4-cycle engine 3 is arranged in the 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 contains a crankcase 9 for housing a crankshaft 8 and 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 (see FIG.
And a cylinder head 13 that configures FIG. 5).

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 has 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 the valve operating device 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. 4 and 5.

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. 7, 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 the 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 and the exhaust valve 22, the valve spring 28, the intake rocker arm 27A and the exhaust rocker arm 27B are incorporated through inspection windows 41A and 41B opened in front of and behind the cylinder head 13. Each of these inspection windows 41A and 41B has an inspection cap 42A and an inspection cap 42A shown in FIG.
It is closed by 42B. Further, the cam shaft 29, the cam chain driven sprocket 31 and the like shown in FIG. 4 have an assembling window 43 opened on the left side of the cylinder head 13.
Incorporated from. 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 FIGS. 1 and 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 4, the camshaft 29 is mounted on the cylinder head 1 by the bearing 46.
3 is rotatably supported, and a main oil passage 47 for guiding lubricating oil is formed inside. The main oil passage 47 extends over the entire length of the cam shaft 29 and communicates with the oil outlet 48 of the flywheel 32. The camshaft 29 is formed with a first sub oil passage 49 communicating with the main oil passage 47 and reaching the cam surfaces of the intake cam 26A and the exhaust cam 26B.
Guide the lubricating oil inside to both the cam surfaces.

Further, a second sub oil passage 50 is formed in the cam shaft 29 near the position where the bearing 46 is arranged. The second sub oil passage 50 communicates with the main oil passage 47, and has an intake cam 26A and an exhaust cam 26B.
Each of which is inclined toward the intake cam 26
It is provided at a position other than A and the exhaust cam 26B.

On the outer periphery of the camshaft 29, substantially ring-shaped oil guide portions 51 and 52 are arranged. These oil guide portions 51 and 52 are sandwiched and fixed between the journal portion step portion 53 of the cam shaft 29 and the inner race 54A of the bearing 46. These oil guide portions 51 and 52 are U-shaped in cross section and extend upward of the intake cam 26A and the exhaust cam 26B, and are provided so as to face the outlet opening of the second sub oil passage 50. Therefore, the lubricating oil that has reached the inside of the second sub oil passage 50 from the main oil passage 47 will not be fed to the oil guides 51, 52.
It collides with the inner surface and is guided to the cam surfaces of the intake cam 26A and the exhaust cam 26B.

On the other hand, in the cylinder head L cover 44,
As shown in FIGS. 1 and 8, a plurality of inner fins 55A and a plurality of outer fins 55B are formed on the inner surface and the outer surface, respectively.
The inner fins 55A and the outer fins 55B cool the lubricating oil in the cam chain chamber upper space 56A formed by being surrounded by the cylinder head 13 and the cylinder head L cover 44.

By the way, the above-mentioned lubricating oil is guided to an oil passage 57 in the cylinder head R cover 45 shown in FIG. 1 through an oil passage (not shown) by an oil pump (not shown) driven by the crankshaft 8. The oil is introduced from the oil passage 57 into the main oil passage 47. The lubricating oil in the main oil passage 47 reaches the cam surfaces of the intake cam 26A and the exhaust cam 26B directly from the first sub oil passage 49, and is guided by the oil guide portions 51 and 52 from the second sub oil passage 50 to intake air. Cam 26
A and the cam surface of the exhaust cam 26B. The lubricating oil thus guided lubricates the cam surface of the intake cam 26A and the cam slipper portion 39 of the intake rocker arm 27A,
In addition, the cam surface of the exhaust cam 26B and the exhaust rocker arm 27
Lubrication with the B cam slipper portion 39 is sufficiently performed.

Further, the lubricating oil in the main oil passage 47 passes through the oil outlet 48 of the flywheel 32, flows toward the outer peripheral direction by the centrifugal force, and scatters in the upper space 56A of the cam chain chamber, causing the cam chain 34 to move. Lubricate. The lubricating oil scattered in the upper space 56A of the cam chain chamber further lubricates the sliding portion 55 between the sprocket mounting flange 30 and the cylinder head 13 together with the lubricating oil after lubricating the bearing 46, as shown in FIG. To do.
The sprocket mounting flange 30 makes sliding contact with the cylinder head 13 at the sliding contact portion 55, whereby the position of the camshaft 29 in the thrust direction is regulated.

Now, as shown in FIG. 3, the cylinder block 11 is installed in the crankcase 9 while leaning forward until it becomes substantially horizontal with respect to the surface horizontal line S. Further, the cam chain driven sprocket 31, the cam chain drive sprocket 33 and the cam chain 34 shown in FIG. 4 form a cam chain drive system. This cam chain drive system is housed in a cam chain drive chamber 56 (FIG. 4) formed across the crankcase 9, the cylinder block 11 and the cylinder head 13. The cam chain chamber upper space 56A is a part of the cam chain drive chamber 56.

Further, the cylinder head 13 is formed with a rocker arm accommodating chamber 59 which is separated from the cam chain drive chamber 56 by the cylinder head inner wall 58. In the rocker arm accommodating chamber 59, the intake rocker arm 27
A, the exhaust rocker arm 27B, and the camshaft 29 are housed. Then, on the inner wall 58 of the cylinder head,
Cam chain drive chamber 56 and rocker arm accommodation chamber 59
A communication hole 60 that communicates with each other is formed as shown in FIG.

As described above, the cylinder head 13 is provided with the inspection caps 42A and 42B (FIG. 5).
42B are inspection windows 41A and 41B of the cylinder head 13 via gaskets 61A and 61B, respectively.
Attached to each. By removing the inspection cap 42A and the gasket 61A or the inspection cap 42B and the gasket 61B, the inspection windows 41A and 41B are opened, and the intake rocker arm 27A and the exhaust rocker arm 27B.
The adjustment screw 40 can be adjusted to adjust the tappet. Therefore, the gasket 61A, the inspection cap 42A, and the gasket 61B.
The inspection cap 42B and the inspection cap 42B each function as a tappet adjusting cover member.

Of these, the inspection cap 42
B and the gasket 61B are provided close to the surface horizontal line S, and the inspection cap 42A and the gasket 61A are provided at positions apart from the surface horizontal line S. Then, the breather chamber 62 is formed in the inspection cap 42A and the gasket 61A.

That is, the inspection cap 42A
A union pipe 63 is fitted to the union pipe 63 as shown in FIGS. 9 (A), 9 (B) and 9 (C).
A partition protrusion 64 is provided on the inner surface in the vicinity of the inspection cap 42A so as to extend over the entire length in the width direction of the inspection cap 42A. On the other hand, as shown in FIGS. 10A and 10B, a sealing member 65 such as a rubber lip is attached to the gasket 61A over substantially the entire length, and a gasket opening 66 is provided at the center of the gasket 61A. As shown in FIG. 5, the gasket opening 66 is formed at a position corresponding to the adjusting screw 40. Further, as shown in FIG. 10A, a partition protrusion 67 is fixed near the gasket opening 66 at a position substantially corresponding to the partition protrusion 64.

By combining the above-mentioned inspection cap 42A and gasket 61A and attaching them to the cylinder head 13 as shown in FIG. 5, the breather chamber 62 is formed surrounded by the inspection cap 42A and gasket 61A. The blow-by gas (combustion chamber waste gas) that has flowed from the inside of the combustion chamber 12 through the gap between the piston 10 and the cylinder block 11 into the crankcase 9 passes through the communication hole 60 from the inside of the cam chain drive chamber 56 of FIG. It reaches the room 59. The blow-by gas that has reached the rocker arm accommodation chamber 59 reaches the inside of the breather chamber 62 through the gasket opening 66, and is discharged from the union pipe 63 through the gap between the partition projection piece 67 and the partition projection 64. A breather hose 68, which is generally connected to an air cleaner (not shown), is connected to the union pipe 63.
The blow-by gas discharged from 3 is guided to the air cleaner and burned again.

According to the above embodiment, the lubricating oil scattered from the main oil passage 47 of the camshaft 29 through the second sub oil passage 50 is guided by the oil guide portions 51 and 52, and the intake cam 26A and the exhaust cam 26B.
From the first sub-oil passage 49 to the intake cam 26A and the exhaust cam 26B together with the lubricating oil, the cam slipper portion 3 of the intake rocker arm 27A.
9, the intake cam 26A, the cam slipper portion 39 of the exhaust rocker arm 27B, and the exhaust cam 26B can be sufficiently lubricated. As a result, the durability of the valve gear is improved and the life of the valve gear can be extended.

Further, of the inspection caps 42A and 42B, the inspection cap 42A located at a position distant from the ground surface horizontal line S is in a position where it is less susceptible to pressure fluctuations in the crankcase 9. That is, the pumping pressure by the piston 10 is applied from the inside of the crankcase 9 to the cam chain drive chamber 56 and the rocker arm accommodation chamber 59.
It is attenuated while being sequentially transmitted to. Especially, in the communication hole 60 between the cam chain drive chamber 56 and the rocker arm accommodation chamber 59, the pumping pressure is significantly attenuated. Since the breather chamber 62 is composed of the inspection cap 42A and the gasket 61A,
The blow-by gas leaked into the crankcase 9 flows into the breather chamber 62 from the gasket opening 66 of the gasket 61A through the cam chain drive chamber 56 and the rocker arm accommodation chamber 59, and is discharged through the union pipe 63. Since it is less affected by, it will not be discharged more than necessary.

Further, even if the engine 3 is greatly inclined when the vehicle falls, a large amount of lubricating oil is not accumulated in the rocker arm accommodating chamber 59, so that the lubricating oil flows into the breather chamber 62 and enters into the engine 3. It is possible to prevent the stored lubricating oil from blowing out.

Further, the breather chamber 62 is not constituted by a dedicated part constituting the breather chamber 62, but the inspection cap 4 having another function.
Since it is composed of 2A and the gasket 61A, there is no waste and no increase in cost occurs.

Further, since the inner fins 55A and the outer fins 55B are formed on the cylinder head L cover 44, the lubricating oil scattered in the upper space 56A of the cam chain chamber adheres to the inner fins 55A as shown in FIG. While flowing between these inner fins 55A, the outer fins 55B
Is heat-exchanged and cooled. As a result, the lubricating oil can be cooled well.

In addition, since the oil guides 51 and 52, the breather chamber 62, etc. are made of compatible members, they are compatible with existing vehicles and have a simple structure. Good maintainability.

11 (A) and 11 (B) are a plan view and a sectional view, respectively, showing a modification of the inspection cap.

In this modification, the inspection window 41
The inspection cap 70 attached to A is
It is configured by combining an undercap 72 and an upper cap 73. An undergasket 74 is provided between the undercap 72 and the inspection window 41A, and an upper gasket 7 is provided between the undercap 72 and the upper cap 73.
5 are inserted respectively. The under gasket 74 has
An under opening 76 is formed at a position corresponding to the adjusting screw 40 of the intake rocker arm 27A, and an upper opening 77 is formed in the upper gasket 75. Further, a partition projection 78 having the same shape as the partition projection 64 is formed on the upper cap 73, and the union pipe 73 is fitted therein.

The blow-by gas that has reached the rocker arm chamber 59 is guided from the under opening 76 through the upper opening 77 into the upper cap 73, and is discharged from the union pipe 63 through the partition projection 78. According to this modified example, the breather chamber 71 is composed of the undercap 72 and the upper cap 73, and the volume of the breather chamber 62 can be made larger than that of the breather chamber 62 by the presence of the undercap 72. Can be prevented.

In the above embodiment, the cylinder head 1
Although the cylinder head inner wall 58 of No. 3 has the communication hole 60 formed therein, the inner race 54A of the bearing 46 is described.
The cam chain drive chamber 56 and the rocker arm housing chamber 59 may be communicated with each other by utilizing the gap between the outer race 54B and the outer race 54B.

[0047]

As described above, according to the first aspect of the present invention, the oil passage through which the lubricating oil flows is formed inside the camshaft, and the cam direction is provided between the camshaft and the cylinder head member. Is arranged so that the lubricating oil scattered from the oil passage collides with the oil guide portion and is guided to the cam. Therefore, the cam of the camshaft and the rocker arm of the valve operating device are Good lubrication with the cam slippers can be achieved.

According to the four-cycle engine of the second aspect, the camshaft drive chamber for accommodating the camshaft drive system and the rocker arm accommodating chamber for accommodating the rocker arm communicate with each other and face the rocker arm accommodating chamber. ,
Since the breather chamber is formed in the cover member for adjusting the tappet between the intake / exhaust valve and the rocker arm, which is away from the ground horizon, of the cover member for adjusting the tappet, this breather chamber is a place that is less susceptible to pressure fluctuations in the crankcase. Therefore, it is possible to prevent unnecessary blow-by gas from being blown out from the breather chamber.

[Brief description of drawings]

FIG. 1 is a partially enlarged view of FIG. 4, showing an embodiment of a 4-cycle engine according to the present invention.

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

3 is an overall side view of the engine of 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.

FIG. 6 is a view on arrow VI of FIG.

7 is a sectional view taken along line VII-VII of FIG.

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

9A is an inspection cap 42 of FIG.
The top view which shows A, (B) is sectional drawing which follows the IXB-IXB line of (A), (C) is the inspection cap 4 of (A).
The bottom view of 2A.

10A is a plan view showing the gasket / breather plate of FIG. 5, and FIG. 10B is a sectional view taken along line XB-XB of FIG.

11A is a plan view showing a modified example of the inspection cap, and FIG. 11B is a sectional view taken along line XIB-XIB.

[Explanation of symbols]

 9 crankcase 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 38A intake side rocker shaft 38B exhaust side rocker shaft 42A inspection cap 47 main oil passage 50 second Sub oil passages 51, 52 Oil guide 56 Cam chain drive chamber 59 Rocker arm accommodating chamber 60 Communication hole 61A Gasket 62 Breather chamber

Claims (2)

[Claims] 1. A cylinder head member is provided with a cam shaft integrally formed with a cam and a rocker shaft pivotably supporting a rocker arm, one end of the rocker arm abutting an intake / exhaust valve and the other end of the rocker arm. In a four-cycle engine provided with a valve operating device in which a cam slipper portion comes into contact with the cam and the rotation of the cam operates the intake / exhaust valve, an oil passage through which lubricating oil flows is provided inside the camshaft. An oil guide portion that is formed and extends in the cam direction is disposed between the cam shaft and the cylinder head member, and lubricating oil scattered from the oil passage collides with the oil guide portion and is guided to the cam. A four-cycle engine characterized by being configured as described above. 2. A cylinder block is tilted forward in a crankcase for accommodating a crankshaft, and a camshaft integrally formed with a cam and a rocker arm are swingably mounted on a cylinder head member installed in the cylinder block. A rocker shaft for supporting the rocker shaft is installed, 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 rotation of the cam activates the intake / exhaust valve. In a four-cycle engine equipped with a valve device, a camshaft drive system for rotating the camshaft by the rotational force of the crankshaft is housed in a camshaft drive chamber formed across the crankcase, cylinder block and cylinder head member. The rocker arm accommodating chamber for accommodating the rocker arm is provided with the cam. A breather chamber is formed in a cover member, which is formed in communication with the shaft drive chamber and faces the rocker arm accommodating chamber and which adjusts the tappet of the intake / exhaust valve and the rocker arm, away from the ground horizontal line. A four-cycle engine characterized by this.