JPH0536968Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lubrication structure for a valve train in a DOHC engine mounted horizontally or tilted close to horizontally.

[Conventional technology]

Conventionally, lubrication structures have been known in which the valve train is lubricated with the engine tilted sideways (for example, Utility Model Publication No. 32-12222, Utility Model Application Publication No. 1983)
−183807).

In the engine disclosed in the above-mentioned Japanese Utility Model Publication No. 32-12222, the stems of the intake and exhaust valves are tilted horizontally, and oil is supplied from above the head to the oil distribution pan. The oil is guided from the outlet to the target lubrication area through channels, holes, and conduits.

Furthermore, in the engine disclosed in Japanese Patent Application Laid-Open No. 58-183807, the camshaft is tilted vertically, and a guide provided at a portion located above the cam surface of the camshaft is used. The means supplies lubricating oil toward the cam surface.

The engine is normally mounted upright with the top of the piston facing upward, but due to space constraints, the engine may be mounted horizontally.

FIGS. 6 to 8 show the lubrication structure of a conventional valve train when a DOHC engine is tilted horizontally. In the figure, 1 indicates a cylinder head, and 2 and 3 indicate a camshaft. One camshaft 2 is located above the other camshaft 3.
The camshafts 2 and 3 have oil holes 2 extending along the central axis.
a, 3a are formed, and these oil holes 2a, 3a
Lubricating oil is supplied from the camshafts to the cam bearings of cam caps 4 and 5 that support the respective camshafts. Then, the cam surfaces 2b of the camshafts 2 and 3,
2b', 3b, 3b' and valve lifters 6, 6', 7,
The sliding part 7' is designed to be lubricated.

Further, the valve lifter holding portion 8 of the cylinder head 1 that holds the valve lifters 6, 6', 7, 7',
9, 10, and 11 are formed in independent shapes on the upper camshaft side and the lower camshaft side with the spark plug hole 12 as a boundary.

[Problem that the invention attempts to solve]

However, in the above structure, the lubricating oil that lubricates the cam and valve lifter of the camshaft located above drips downward due to gravity, and the cam and valve lifter located below are not sufficiently supplied with lubricating oil. , there was concern that lubrication in this part would deteriorate. In other words, in the conventional lubrication structure, each valve lifter holding part is independent, so the lubricating oil that lubricates the cam of the upper camshaft and the sliding part of the valve lifter does not flow downward along the wall surface of the valve lifter holding part. There were concerns about deterioration of cam and valve lifter lubrication.

The present invention provides a lubrication structure that can sufficiently guide the lubricating oil that lubricates the cams and valve lifters of the upper camshaft to the lubrication parts of the cams and valve lifters of the lower camshaft, and further improves the lubricity of the valve train. The purpose is to

[Means for solving problems]

The lubrication structure of the valve train in the engine of the present invention that meets this purpose is applicable to engines equipped with a direct-acting valve train in which the mounting position is horizontal or tilted close to horizontal, and two camshafts are arranged in the cylinder head. , an upper valve lifter holding part and a lower valve lifter holding part formed in the cylinder head of the engine are connected via a connecting part formed with a flat surface, and each valve lifter holding part and the connecting part are connected to each other, A lubricating oil guide rib is provided that extends continuously from the upper valve lifter holding part to the lower valve lifter holding part and curves once toward the center of the lower valve lifter holding part at the connection part.

[Effect]

In the lubrication structure of the valve train in the engine configured as described above, the lubricating oil that lubricates the upper camshaft and the valve lifter flows along the wall surface of the cylinder head where the valve lifter holding portion is located. In this case, the upper valve lifter holding part and the lower valve lifter holding part are connected via a connecting part whose surface is formed into a flat surface, and each valve lifter holding part and the connecting part have a connection extending in the vertical direction. Since a lubricating oil guide rib is provided that curves once at the bottom, the lubricating oil flowing along the wall surface of the cylinder head is reliably directed to the cam surface of the camshaft below and the sliding part of the valve lifter. The lubricity of this part is greatly improved.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a lubrication structure for a valve mechanism in an engine according to the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a lubrication structure for a valve train in an engine according to a first embodiment of the present invention. In the figure, reference numeral 21 indicates a cylinder head of a DOHC engine equipped with a direct-acting valve train, which is mounted on a vehicle in a horizontal position. Two cam shafts 22 and 23 are horizontally arranged in parallel on the cylinder head 21. The camshaft 22 is the camshaft 23
It is located above the cam cap 24 and is held by a bolt 25 inserted through the cam cap 24. The camshaft 23 is similarly held by a cam cap 26 and a bolt 27 inserted through the cam cap 26. A spark plug hole 48 is formed in a portion of the cylinder head 21 between the cam cap 24 and the cam cap 26.

The cams 22a, 22a' of the camshaft 22 are in contact with the tops of direct-acting valve lifters 28, 28' for intake (exhaust) provided on the cylinder head 21 side. Similarly, the cams 23a, 23 of the camshaft 23
a′ is direct-acting valve lifter 2 for exhaust (intake)
9 and 29'. The direct-acting valve lifters 28, 28', 29, 29' are held by valve lifter holding portions 30, 31, 32, 33 provided for each cylinder of the cylinder head 21. Each valve lifter holding part 30, 3
1, 32, 33 have holes 30a, 31a, 32
a, 33a are formed, and the valve lifter 2
8 and 28' are slidably inserted and held in the holes 30a and 31a. Valve lifter 29, 2
9' is slidably inserted and held in the holes 32a and 33a.

A valve spring 34 is disposed on the back side of the valve lifters 28, 28'. The shaft portion 35a of the intake valve 35 is located inside the valve spring 34.
is disposed, and the end of the shaft portion 35a is in contact with the back surface of the valve lifter 28. Intake valve 3
A retainer lock 36 is provided on the outer periphery of the shaft portion 35a of 5.
A valve spring retainer 37 is attached via the valve spring retainer 37. A valve spring 34 is brought into contact with one side of the valve spring retainer 37, thereby biasing the intake valve 35 in the closing direction.

A valve spring 49 is disposed on the back side of the valve lifters 29, 29'. The shaft portion 38a of the exhaust valve 38 is located inside the valve spring 49.
is disposed, and the end of the shaft portion 38a is in contact with the back surface of the valve lifter 29. Exhaust valve 3
A retainer lock 39 is provided on the outer periphery of the shaft portion 38a of 8.
A valve spring retainer 40 is attached via. A valve spring 49 is brought into contact with one side of the valve spring retainer 40, thereby biasing the exhaust valve 38 in the closing direction.

Valve lifter holding portions 30 and 31 that hold intake valve lifters 28 and 28' are provided on the left and right sides of the cam cap 24, respectively.
Valve lifter holding parts 32 and 33 that hold the exhaust valve lifter 29 are located below the above-mentioned valve lifter holding parts 30 and 31, and are located below the cam cap 26.
They are located on the left and right sides of the border.

In the conventional structure of this valve lifter holding part, as shown in FIG. 6, each valve lifter holding part has an independent shape bordering on the vicinity of the spark plug hole 12, but in the present invention, the valve lifter holding parts located in the vertical direction are Connected near the spark plug hole.

That is, the valve lifter holding part 30 located above and the valve lifter holding part 32 located below this valve lifter holding part 30 are connected via a connecting part 84 located near the spark plug hole 48. A surface 84a of the connecting portion 84 is formed into a flat surface. The surface 84a of the connecting portion 84 is
It is smoothly connected to the surface of each valve lifter holding part 30, 32. The connecting portion 84 is narrower in the direction of the spark plug hole 48 than the valve lifter holding portions 30 and 32.

Valve lifter holding parts 30, 32 and connection part 8
4, a lubricating oil guide rib 8 extending from above to below the valve lifter holding portion 30 is located at the right end of the figure.
5 is provided. As shown in FIG. 1, the lubricating oil guide rib 85 has a substantially doglegged planar shape that curves toward the center of the lower valve lifter holding portion 32. As shown in FIGS. 2 and 3, the lubricating oil guide rib 85 extends horizontally (camshafts 22, 23
It is formed so as to protrude to the side). The lubricating oil guide rib 85 has a function of guiding lubricating oil that lubricates the camshaft 22 and valve lifter 28 located above to the camshaft 22 and valve lifter 29 located below.

Valve lifter holding parts 31 and 33 located on the left side of the figure with the cam caps 24 and 26 as boundaries are also connected via a connecting part 86 located near the spark plug hole 48 in the same manner as described above. Connection part 86
The surface 86a is formed into a flat surface. The surface 86a of the connecting portion 86 is connected to each valve lifter holding portion 3.
It is smoothly connected to the surfaces of 1 and 33. This connecting portion 86 is also narrower in the direction of the spark plug hole 48 than the valve lifter holding portions 31, 31.

Valve lifter holding parts 31, 33 and connection part 8
At the left end of the figure in FIG.
7 is provided. The shape of the lubricating oil guide rib 87 is symmetrical to the above-mentioned guide rib 85 with respect to the center line C passing through the cam caps 24 and 26.
That is, the planar shape of the lubricating oil guide rib 87 is approximately in an inverted dogleg shape that curves toward the center of the lower valve lifter holding portion 33 . Lubricating oil guide rib 87
are formed to protrude in the horizontal direction (towards the camshafts 22 and 23) similarly to the lubricating oil guide ribs 85.

In this way, by providing the lubricating oil guide ribs 85 and 87, each valve lifter holding portion 30 and 3
1, 32, 33 and the connecting portions 84, 86 are formed in a groove shape as shown in FIG.
and the sliding parts of the valve lifters 29, 29'.

Next, the operation in the first embodiment will be explained.

Lubrication of the valve train is performed by lubricating oil supplied to oil holes 22b, 23b of camshafts 22, 23. The lubricating oil forced into the oil holes 22b, 23b is discharged from oil holes 22c, 23c located at the positions of the cam caps 24, 26. Oil hole 22
The lubricating oil discharged from the cam 2 of the camshaft 22
2a, 22'a and the sliding portions of valve lifters 28, 28' that contact the cams 22a, 22'a. The lubricating oil that has lubricated the cam 22a and the valve lifter 28 flows downward along the upper wall surface of the valve lifter holding portion 30 due to gravity.

In this case, the valve lifter holding part 30 and the valve lifter holding part 32 located below are connected by a connecting part 84 having a flat surface, and the valve lifter holding parts 30, 32 and the connecting part 84 are connected from above. Lubricating oil guide rib 8 that extends continuously downward
5, the lubricating oil that has lubricated the upper cam 22a and the valve lifter 28 flows along the smooth surface of the connecting portion 84 and is reliably guided to the cam 23a of the lower camshaft 23 and the valve lifter 29. .

Similarly, the lubricating oil supplied to the sliding parts of the cam 22'a of the camshaft 22 and the valve lifter 28', which are provided on the opposite side of the cam cap 24, is guided by the lubricating oil guide rib 87 and connected. It flows downwardly along the smooth surface of section 86. Therefore, the upper lubricating oil is absorbed by the cam 23' of the camshaft 23.
a and the valve lifter 29' that comes into contact with the cam 23'a.

In this way, the upper camshaft 22 in each cylinder
cams 22a, 22'a and valve lifters 28, 2
8' is now sufficiently guided to the cams 23a, 23'a of the lower camshaft 23 and the valve lifters 29, 29', and the lubricity of the lubricated parts in these parts is significantly improved, and the cams and The durability of the valve lifter is increased.

Second Embodiment FIGS. 4 and 5 show a lubrication structure for a valve train in an engine according to a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is the position of the oil hole that supplies lubricating oil to the cam of the upper camshaft and the valve lifter. By assigning the same reference numerals as in the first embodiment, description of the corresponding parts will be omitted, and only different parts will be described.

4 and 5, reference numeral 41 indicates an oil passage formed within the cylinder head 21. In FIGS.
The oil passage 41 is located above the valve lifter holding parts 30, 31 above the cylinder head 21, and is formed to extend in the longitudinal direction of the engine. Oil holes 42 and 43 connected to an oil passage 41 are formed in each cylinder of the cylinder head 21. The oil hole 42 is provided directly above the valve lifter 28 and opens toward the valve lifter 28. In addition, the oil hole 43 is similarly connected to the valve lifter 2.
It is provided directly above the valve lifter 8' and opens toward the valve lifter 28. Although the oil passage 41 is integrally formed within the cylinder head 21 in this embodiment, it may be formed using a separate member.

In the second embodiment configured in this way,
The lubricating oil forced into the oil passage 41 flows through the oil holes 42 and 4.
Almost all of the lubricating oil discharged from this oil hole is supplied to the valve lifters 28, 28' and the cams 22a, 22'a of the camshaft 22.
As a result, the cams 22a, 2 of the upper camshaft 22
2'a and valve lifters 28, 28' are well lubricated. The lubricating oil that has lubricated the upper cams 22a, 22'a and the valve lifters 28, 28' flows downward by gravity. In this case, the upper valve lifter holding members 30, 31 are connected to the connecting portion 84,
86, the lower valve lifter holding member 32,
33, and lubricating oil guide ribs 85, 87 are provided at each valve lifter holding portion and the connecting portion, so that the cams 23a, 23'a of the lower camshaft 23 are connected to each other, as in the first embodiment. This allows sufficient lubricating oil to be supplied to the valve lifters 29, 29'. Therefore, in this embodiment, the sliding parts of both the upper and lower valve lifters can be sufficiently lubricated.

Although this embodiment shows an example of an engine having four valves per cylinder, this structure can also be applied to engines other than four valves. It is also applicable to those that supply lubricating oil directly from the cam.

[Effect of idea]

According to the lubrication structure of the valve train in the engine of the present invention, the upper valve lifter holding part and the lower valve lifter holding part formed in the cylinder head are connected via the connecting part formed with a flat surface. , each valve lifter holding part and the connecting part are provided with a guide rib that extends continuously from the upper valve lifter holding part to the lower valve lifter holding part and curves once toward the center of the lower valve lifter holding part at the connecting part. Therefore, the lubricating oil that lubricates the cam and valve lifter of the camshaft located above can be sufficiently guided to the cam and valve lifter of the camshaft located below, greatly improving the lubrication performance of the cam and valve lifter located below. can be done.

Therefore, wear of the cam of the camshaft and the valve lifter is suppressed to a minimum, and the durability of the camshaft and the valve lifter can be significantly increased.

[Brief explanation of the drawing]

1 is a partial plan view of a lubrication structure of a valve mechanism in an engine according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG.
4 is a partial plan view of a lubrication structure of a valve mechanism in an engine according to a second embodiment of the present invention; FIG. 5 is a sectional view taken along line - in FIG. 4; FIG. 6 is a partial plan view of the lubrication structure of the valve mechanism in a conventional engine with a horizontal mounting position, and FIG. 7 is a sectional view taken along the - line in FIG. 6.
FIG. 8 is a sectional view taken along the - line in FIG. 6. 21... Cylinder head, 22, 23... Camshaft, 22a, 22'a, 23a, 23'a... Cam, 22c, 23c, 42, 43... Oil hole, 2
8, 28', 29, 29'...Valve lifter, 3
0, 31, 32, 33...Valve lifter holding part,
84, 86... Connection portion, 85, 87... Lubricating oil guide rib.

Claims (1)

[Scope of utility model registration request] In an engine equipped with a direct-acting valve mechanism in which the mounting position is horizontal or tilted close to horizontal and two camshafts are arranged in the cylinder head, an upper valve lifter holding part and a lower valve lifter holding part formed in the cylinder head of the engine are used. and the valve lifter holding part through a connecting part formed with a flat surface,
A lubricating oil guide rib is provided on each of the valve lifter holding parts and the connecting part, and extends continuously from the upper valve lifter holding part to the lower valve lifter holding part, and curves once toward the center of the lower valve lifter holding part at the connecting part. A lubrication structure for a valve mechanism in an engine, characterized in that it is provided with.