JP2819205B2 - Rocker arm for engine valve system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a rocker arm of the engine valve train, in particular, it relates to a rocker arm which reduce the weight.

[0002]

BACKGROUND ART As the rocker arm of the conventional OHC engine valve train is, for example, as shown in FIG. This
The OHC end pivot (swing arm) type rocker arm has a cylinder head (10) at one end of the arm body (101).
An end pivot portion (101a) pivotally supported is formed on a spherical head-shaped pivot (103) fitted in 2), and the other end also contacts the end face of the engine valve shaft (104). , Engine
Valve shaft abutments for opening and closing the Nbarubu (101b) is formed,
The end pivot part (101a) and the valve shaft contact part (101b) are integrated by a pair of left and right arms (101d), and the end pivot part (101a) and the valve shaft contact part are further integrated. the part roller housing portion between <br/> between the pair of left and right side pieces (101b) (101d) (101e), in order to the small friction between the cam (106), a cam (106 ) to the can contact roller (105), shaft (10 fixed to the shaft hole (101c)
Is supported by the 7) is rotatably accommodated.

[0003] Such a rocker arm having a roller (105) has a roller (10) as compared with a normal rocker arm.
5) Weight extent that is added is increased, the inertia mass Daito such because, the motion limit lowered, applicable child for high-speed rotation
And it is difficult. Therefore , attempts have been made to form the arm body (101) from a light alloy material to reduce the weight of the entire rocker arm.

[0004]

However , the arm body (1
When (01) is formed of a light alloy material, the wear resistance is inferior due to the characteristics of the light alloy material, so that it is pivotally supported by the valve shaft contact portion (101b) and the pivot (103) that contact the engine valve (104). The inner surfaces of the left and right side pieces (101d) with which the side surfaces of the end pivot portion (101a) and the roller (105) slide are significantly worn,
Early backlash occurs in, and by their abrasion powder, the roller (105) and that the normal operation of the rocker arm is prevented
Becomes

In view of the above-mentioned problems of the prior art, the present invention is intended to reduce the weight by forming the rocker arm from a light alloy material and to prevent wear of the abutting portions and sliding portions of each portion. Te, and so it can improve abrasion resistance, and to provide a rocker arm of the engine valve train.

[0006]

To achieve the above object, according to an aspect of the present invention, one end of the arm body, to form a contactable valve shaft abutments on the end of an engine valve shaft <br/>, Similarly, at the other end, an end pivot portion pivotally supported by a pivot provided on the cylinder head is formed , and the valve shaft contact portion and the end pivot portion are integrated via a pair of left and right side pieces. In a rocker arm of an engine valve operating system in which a roller that can come into contact with a cam is rotatably supported on a support shaft provided between inner side surfaces of an arm portion, a valve shaft support in the arm body is provided.
All of the inner surface of the contact part, the end pivot part and the pair of left and right side pieces
It is characterized in that a wear-resistant member integrally formed is cast over the surface.

[0007]

A wear-resistant member integrally formed is cast into the end pivot portion of the arm body, the valve shaft contact portion, and the inner surfaces of the pair of left and right side pieces , so that the pivot and engine provided on the cylinder head are provided. The wear resistance of the sliding surface with the valve shaft and the roller is significantly improved. Therefore, even if the arm main body is formed of a light alloy material, there is no problem in wear resistance, the weight of the rocker arm can be reduced, and the allowable rotation speed of the engine can be increased.

[0008]

EXAMPLES Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. (1) is an arm body of a rocker arm integrally formed of a light alloy material such as an aluminum alloy. One end of the arm body is swingably fitted to a pivot (5) fitted to a cylinder head (2). An end pivot portion (1a) having a pivot groove (1c) is formed, and the other end is guided by a cylinder head (2) so as to be able to move up and down, and is always moved in a valve closing direction by a valve spring (3). A valve shaft contact portion (1b) that can contact the end surface of the urged engine valve shaft (4 ) is formed. Valve shaft contact part (1b)
And the end pivot part (1a) through a pair of left and right side pieces (1d) .
It is integrated .

[0009] The substantially central portion of the left and right side pieces (1d), the axial hole (1f) is bored by post-processing, and have your valve shaft abutments and (1b) end pivot portion between (1a), the roller accommodating portion formed between the left and right side pieces (1d) (6), capable of abutting against the roller with the cam (9) which rotates with the camshaft (8), a shaft hole (1f)
By non-rotatably fitted to a shaft (7), it is inserted and is rotatably supported and on. (10) is a wear-resistant member integrally formed of a sintered alloy or the like, and includes a pivoting part (10a) cast into the end pivot part (1a) of the arm body (1) and a valve contact part (1b). ) And the side surface (1e) cast on the inner surface (1e) of the side piece (1d) where the side surface of the roller (8) slides.
0c).

[0010] roller (8) rotates in conjunction with the cam (9), if you press ridges (9a) the roller (8) of the cam (9), the arm body (1), the end pivot part and cast into (1a) pivotally supporting the pivot (5) wear resistant member that is fitted to the (10) (10a)
As a fulcrum, the contact portion of the valve shaft abutting portion swings so that to lower the (1b), the valve shaft abutments wear resistant member (10) being cast into (1b) ( 10b) is, against the biasing force of the valve spring (3), by pressing the engine valve shaft (4)
The engine valve is opened.

In the first embodiment, the pivot (5)
The three parts of the pivoting part (10a), the contact part (10b) that contacts the engine valve shaft (4), and the side part (10c) where both sides of the roller (8) are in sliding contact are connected. the wear resistant member (10) molded integrally Te, in <br/> of Aru is cast on the arm body (1), although the arm main body (1) is made of light alloy, the respective parts improved wear resistance, row accurate operation for a long time
Align, and suppressing the occurrence of abrasion powder can Rukoto to perform long-term normal operation.

[0012]

According to the present invention, the following effects can be obtained. (a) The end pivot portion and the valve shaft contact portion of the arm body and the inner surfaces of the pair of left and right side pieces are integrally formed on the entire surface.
By casting the formed abrasion resistant member, the abrasion resistance of each sliding contact surface is remarkably improved. (b) End pivot part, valve shaft contact part and inside of side piece
Wear-resistant members cast over the entire surface are integrally formed.
The strength of the arm body has been improved,
And the thickness of each part of the arm body can be reduced.
The weight of the entire arm can be reduced, enabling high-speed rotation
We can respond enough. (c) The inertia mass of the arm body molded from a light alloy material
And improve the permissible engine speed and maximum output of the engine
can do.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, showing a mounted state of a rocker arm.
It is the schematic of an Example.

FIG. 2 is a bottom view of the rocker arm according to the first embodiment.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

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

FIG. 5 is a conventional OHC, end pivot type rocker.
FIG. 3 is a schematic view in a mounted state of the program.

[Description of Signs] (1) Arm body (1a) End pivot part (1b) Valve shaft contact part (1d) Side piece (1e) Side surface (2) Cylinder head (4) Engine valve shaft (5) Pivot (6 ) Roller storage section (7) Shaft (8) Roller (9) Cam (10) (11) (12) (13) (14) (15) Abrasion resistant member (10a) (12a) (13a) (15a) Pivot (10b) (11b) (14b) (15b) Abutment (10c) (11c) (13c) Side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01L 1/18

Claims (1)

(57) [Claims] One end of claim 1] arm body, to form a contactable valve shaft abutments on the end of an engine valve shaft <br/>, the same other end, is pivotally supported by a pivot provided in the cylinder head The end pivot portion is formed , and the valve shaft contact portion and the end pivot portion are integrated via a pair of left and right side pieces, and the cam and the support shaft provided between the inner side surfaces of both arm portions are provided. In a rocker arm of an engine valve operating system rotatably pivoting a contactable roller, a valve shaft contact portion, an end pivot portion, and a pair of right and left side pieces of the arm main body are provided over the entire inner surface. , One
A rocker arm for an engine valve train characterized by casting a wear-resistant member formed on the rocker arm.