JPH082404Y2 - Internal combustion engine rocker arm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rocker arm of an internal combustion engine, and more particularly to an internal combustion engine that opens and closes a valve body by converting a rotational force from a camshaft into a swinging motion by the rocker arm. Regarding rocker arms.

[Conventional technology]

The rocker arm of the internal combustion engine is pivotally supported by the rocker shaft, and one end of the rocker arm is brought into contact with the cam of the cam shaft.
The other end is in contact with the valve stem of the valve body. And
The rotational force from the camshaft is converted into a swinging motion to press the valve body, for example, the valve stem of the intake valve, to open and close the intake valve.

Further, as disclosed in Japanese Utility Model Laid-Open No. 60-105803, the width of the boss portion provided in the middle of the rocker arm in the axial direction of the rocker arm shaft is formed such that the lower side is wide and the upper side is narrow. There was something that was formed.

[Problems to be solved by the invention]

By the way, in the conventional rocker arm of the internal combustion engine, as shown in FIGS. 6 and 7, the bearing portion 116 penetrating the rocker arm 110 has the same width in the axial direction of the rocker shaft 108. As shown in Fig. 9, the bearing part
In some of the rocker shafts 216, the width in the axial direction of the rocker shaft 208 is formed such that the lower portion is wide and the upper portion is narrow.

As a result, in the former case, the width in the axial direction is formed to be the same in the vertical direction, which causes an increase in weight and the rocker shaft 108.
However, there is an inconvenience that the lubricity is insufficient.

In addition, the latter avoids the above-mentioned inconveniences compared with the former, and the weight and the lubricity of the rocker shaft 208 are slightly improved, but as shown in FIGS. 10 to 12, the latter comes into contact with a cam shaft (not shown). When the pressing portion 314 that presses the valve stem of the valve body (not shown) against the contact portion 318 is curved and formed by 10 mm or more, the rocker arm 310 tilts, and the lubricity of the rocker shaft 308 can be sufficiently ensured. No
This causes the durability of the rocker shaft 308 to be reduced, which is economically disadvantageous.

Further, it is not possible to reliably prevent one-sided contact due to the tilt of the rocker arm 310, and there is a possibility that uneven wear may occur in the bearing portion 316 of the rocker arm 310.

[Purpose of device]

Therefore, an object of the present invention is to provide a rocker arm in which a pressing portion for pressing a valve stem of a valve body is provided on one end side of a swing arm portion while being curved in a desired direction, and a contact portion for contacting a cam shaft is provided on the other end side. The present invention realizes a rocker arm for an internal combustion engine, which improves lubricity of the bearing portion and improves durability, and also can prevent uneven wear by making the pressing portion of the rocker arm small in the bending direction.

[Means for solving problems]

In order to achieve this object, the present invention relates to a rocker arm of an internal combustion engine that converts a rotational force from a camshaft into a swinging motion to open and close a valve element, and provides a bearing part in the swinging arm part of the rocker arm. A pressing portion that presses the valve stem of the valve body is provided on one end side of the swing arm portion while being curved in a desired direction, and a contact portion that comes into contact with the cam shaft is provided on the other end side, and the bearing portion is provided on the bearing portion. The present invention is characterized in that a protruding portion is provided which gradually protrudes in the bending direction of the pressing portion and has a step portion at the inner peripheral portion of the lower end so as to maximize the protrusion at the lower end portion.

[Action]

With the above configuration, when the internal combustion engine is driven, the driving force of the internal combustion engine is transmitted to the camshaft, and the rotational force from this camshaft is converted into a swinging motion by the rocker arm, and Open and close by pressing the valve stem. The rocker arm is provided with a pressing portion that presses the valve stem of the valve body on one end side of the swing arm portion in a curved manner in a desired direction, and a contact portion that contacts the cam shaft on the other end side. With the stepped portion of the protruding portion provided in the lower end portion of the bearing portion on the way to project in the bending direction of the pressing portion, lubricating oil can be accumulated to reliably lubricate the rocker shaft and the bearing portion,
The rocker shaft in the bending direction of the pressing portion can be supported by the protruding portion that protrudes in the bending direction of the pressing portion, and the tilting of the rocker arm can be suppressed.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

1 to 5 show an embodiment of this invention. 1 to 5, 2 is a cylinder head of an internal combustion engine, 4 is
Is a cam shaft, 6 is a cam, and 8 is a rocker shaft. As shown in FIG. 5, a first rocker arm 10 is provided on the upper surface of the cylinder head 2 according to the number of intake valves in order to open and close a valve body, for example, an intake valve not shown.
The second rocker arm 12 is provided according to the number of exhaust valves to open and close the exhaust valves (not shown).

The first and second rocker arms 10 and 12 are pivotally supported on the rocker shaft 8, respectively.

The first rocker arm 10 will be described in detail. As shown in FIGS. 1 to 4, the first rocker arm 10 includes a pressing portion 14 that presses the valve stem of the intake valve and a rocker shaft 8.
Bearing portion 16 supported by the cam 6 and the cam 6 of the camshaft 4
Is integrally formed with a rocking arm portion 20 which connects the contact portion 18, the bearing portion 16 and the pressing portion 14, respectively, and the first rocker arm 10 is
For example, it is formed so that the pressing portion 14 is curved to be displaced from the center line C by the distance S, that is, to be offset due to layout restrictions.

Further, the bearing portion 16 is provided with a protruding portion 24 that gradually protrudes in the bending direction of the pressing portion 14 and has a step portion 22 at the inner peripheral portion of the lower end so as to maximize the protrusion at the lower end portion.

That is, the protruding portion 24 having a gradually smaller protruding amount from the lower end of the bearing portion 16 toward the intermediate portion is provided, and the inner peripheral portion of the lower end is formed to have the largest diameter in the protruding portion 24, and the protruding portion 24 is formed at the intermediate portion of the bearing portion 16. A step portion 22 having a gradually decreasing diameter is formed.

Reference numeral 26 is a boundary portion that divides the inner peripheral portion of the bearing portion 16 and the step portion 22.

 Next, the operation will be described.

When an internal combustion engine (not shown) is driven, the driving force of this internal combustion engine is transmitted to the camshaft 4, and the rotational force from this camshaft 4 is converted into a swinging motion by the first rocker arm 10, for example, and not shown. It opens and closes by pressing the valve stem of the intake valve. Then, as shown in FIG. 1, the lower portion of the rocker shaft 8 abuts on the boundary portion 26, and the upper portion of the bearing portion 16 on the left side in FIG.
Abutting on the upper end portion of the inner circumference.

At this time, a gap 22 is secured between the rocker shaft 8 and the bearing 16 by the step portion 22 of the protrusion 24 provided on the bearing 6 of the first rocker arm 10, and lubricating oil is collected in this gap to accumulate the lubricating oil and the rocker shaft 8 The bearing 16 is reliably lubricated.

Thereby, for example, the bearing portion 16 of the first rocker arm 10
Can improve the lubricity of the first rocker arm 10
The operating life of the first rocker arm 10 can be extended and the durability of the first rocker arm 10 can be improved, which is economically advantageous.

Further, since the protruding portion 24 is provided so as to protrude in the bending direction of the pressing portion 14, the protruding portion 24 causes the rocker shaft 8 in the bending direction of the pressing portion 14 as shown in FIG.
The lower portion of the first rocker arm 10 can be supported to reduce the inclination of the pressing portion 14 of the first rocker arm 10 in the bending direction, and uneven wear of the bearing portion 16 of the first rocker arm 10 can be prevented in advance. This is advantageous.

[Effect of device]

As described in detail above, according to the present invention, a bearing portion is provided in the rocking arm portion of the rocker arm, and the pushing portion for pushing the valve stem of the valve element is bent in a desired direction at one end side of the swing arm portion. A contact portion that comes into contact with the camshaft is provided on the other end side, and the bearing portion is provided with a protruding portion that gradually protrudes in the bending direction of the pressing portion and has a step portion at the inner peripheral portion of the lower end to maximize the protrusion at the lower end portion. So
It is possible to improve the lubricity of the bearing portion of the rocker arm, extend the service life of the rocker arm, and improve the durability of the rocker arm, which is economically advantageous. Also,
Since the protrusion is provided so as to protrude in the bending direction of the pressing part, the inclination of the pressing part of the rocker arm in the bending direction can be made small, and uneven wear of the bearing part that supports the rocker arm can be prevented beforehand. It is possible and practically advantageous.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is an enlarged sectional view of a main part of a rocker arm, FIG. 2 is a sectional view taken along line II-II of FIG. 4, and FIG. 3 is a schematic of FIG. FIG. 4 is a side view, FIG. 4 is a schematic explanatory view of a rocker arm, and FIG. 5 is a schematic plan view of a cylinder head of an internal combustion engine. 6 to 12 show a conventional technique of the present invention, FIG. 6 is a schematic side view of a rocker arm showing a first conventional example, FIG. 7 is a schematic sectional view of a bearing portion of the rocker arm, and FIG. 2 is a schematic side view of a rocker arm showing a conventional example, FIG. 9 is a schematic sectional view of a bearing portion of the rocker arm, FIG. 10 is a schematic side view of a rocker arm showing a third conventional example, and FIG. 11 is a schematic plan view of the rocker arm. FIG. 12 and FIG. 12 are schematic cross-sectional explanatory views of the bearing portion of the rocker arm. In the figure, 2 is a cylinder head, 4 is a camshaft,
6 is a cam, 8 is a rocker shaft, 10 is a first rocker arm, 12 is a second rocker arm, 14 is a pressing portion, 16 is a bearing portion,
Reference numeral 18 is a contact portion, 20 is a swing arm portion, 22 is a step portion, 24 is a protruding portion, and 26 is a boundary portion.

Claims (1)

[Scope of utility model registration request] 1. A rocker arm of an internal combustion engine for converting a rotational force from a cam shaft into a swing motion to open and close a valve element, a bearing part being provided in the swing arm part of the rocker arm, and the swing arm part. A pressing portion for pressing the valve stem of the valve body is provided on one end side of the curved portion in a desired direction, and a contact portion for contacting the cam shaft is provided on the other end side, and the bearing portion has a maximum protrusion at the lower end portion. A rocker arm for an internal combustion engine, characterized in that a protrusion having a step portion is provided at an inner peripheral portion of a lower end thereof so as to gradually protrude in a bending direction of the pressing portion.