JP2860722B2 - Roller rocker arm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller rocker arm used for a valve train of an internal combustion engine.

[0002]

2. Description of the Related Art In an OHC type valve operating mechanism, one end of a rocker arm is supported by a pivot shaft, and the rocker arm is swung up and down by a cam disposed above an intermediate portion of the rocker arm. There is an end pivot (swing arm) type that opens and closes a valve.

[0003] In this end pivot type valve train, the rocker arm and the cam are generally in sliding contact with each other. Therefore, mechanical loss due to friction is relatively large, and in terms of fuel efficiency and output, etc. Disadvantageous. Recently, as a solution to this problem, various roller rocker arms have been proposed in which a rotatable roller is provided at a sliding contact portion of a rocker arm with a cam so as to make rolling contact, thereby reducing friction loss.

[0004]

In the conventional roller rocker arm as described above, a vertically oriented fitting hole is formed in the upper surface of the intermediate portion of the rocker arm body, and the fitting hole is formed by drilling the fitting hole. On both side walls of the rocker arm body, a shaft extending in the left-right direction is penetrated, and with this shaft, the roller disposed in the fitting hole is moved so that the upper part thereof slightly projects from the upper surface of the rocker arm body. The rocker arm must be drilled to form a fitting hole in the rocker arm body, which complicates the manufacturing operation of the rocker arm body. With the positioning and arrangement
The shaft must be inserted from the side of the rocker arm body so as to penetrate the center hole of the roller, and the positioning of the roller and the operation of inserting the shaft are troublesome. There is a problem that the cost is high.

[0005] In particular, when rollers and other bearing members are provided between the roller and the shaft, the assembling work becomes more troublesome, and when the roller is worn, replacement work and maintenance are troublesome. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make it easier to manufacture a rocker arm main body and to make it easier to assemble and replace a roller with the rocker arm main body. , So that the manufacturing cost can be reduced and the rocker arm when the engine is operating
An object of the present invention is to provide a roller rocker arm that fully considers the dynamic balance of the main body .

[0007]

In order to achieve the above object, a roller rocker arm according to the present invention is provided on a cylinder head.
Pivoted to push the engine valve in the other part
One side of the rocker arm body
A recess is formed in the surface, and a rocker arm book is formed in the recess.
The shaft protruding from the body rotates in contact with the rotating cam
Pivoted around the roller, and lock the cylinder head.
Center of the pivot of the hook arm body, the center of the roller,
The center of the contact part between the hook arm body and the engine valve
It is characterized by being arranged on a straight line.

[0008]

[Function] The roller shaft protrudes from one side of the rocker arm main body and is cantilevered, thereby facilitating the assembly and replacement of the roller, as well as facilitating the manufacture of the rocker arm main body and reducing the manufacturing cost. be able to. Further, by forming a concave portion on one side surface of the rocker arm main body and pivotally mounting a roller in the concave portion, the center of the pivotal support portion of the rocker arm main body to the cylinder head, the center of the roller,
When the rocker arm body and the center of the contact portion between the engine valve are arranged on a straight line, the dynamic balance of the rocker arm body during operation of the engine is improved.

[0009]

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

FIGS. 1 and 2 schematically show an end pivot (swing arm) type valve actuating mechanism provided with a roller rocker arm (R) according to an embodiment of the present invention. The spherical hole (1a) formed on the lower surface is fitted from above into the spherical portion (3b) at the upper end of the pivot shaft (3a) of the known hydraulic valve lash adjuster (3) incorporated in the cylinder head (2). The other end is also a pair of cotters (4) (4), a spring retainer
(5) and each member such as a valve spring (6) is in contact with a stem end of an engine valve (7) assembled to the cylinder head (2).

As clearly shown in FIG. 3, one side of the central portion of the rocker arm main body (1) is recessed toward the other side, and faces up and down to the upper and lower surfaces of the rocker arm main body (1). A recess (8) is formed, and one end of a shaft (9) extending in the left-right direction projects from substantially the center of the recess (8) and on one side surface of the rocker arm body (1). In
The roller (10) is pivotally fitted with its upper end slightly protruding from the upper end surface of the rocker arm body (1).

The shaft (9) is composed of a large-diameter flange (9a), a large-diameter shaft (9b) and a small-diameter shaft (9c), and the large-diameter flange (9a) is attached to the rocker arm body (1). By pressing the large-diameter shaft portion (9b) into the shaft hole (11) drilled at the approximate center of the rocker arm body (1) until the small-diameter shaft portion (9c) comes into contact with the side surface, 8) Cantilever supported inside.

A well-known snap ring (12) is engaged with the tip of the small-diameter shaft portion (9c) of the shaft (9), thereby preventing the roller (10) from coming off from the small-diameter shaft portion (9c). Have been.

Thus, by accommodating the roller (10) in the recess (8) of the rocker arm main body (1), the center (O) of the pivotal support of the rocker arm main body (1) to the cylinder head (2) is obtained.
1), (O2) center of roller (10) and rocker arm body
(1) and the center (O3) of the contact portion between the engine valve (7) and the engine valve (7) are arranged on a straight line (L). Dynamic balance is improved.

The roller (10) comes into contact with a rotating cam (13) provided above the roller (10), and the cam (13) is pushed while rotating the roller (10), whereby the rocker arm body (1) is moved. The engine valve (7) is opened and closed by swinging up and down about the pivot shaft (3a) as a fulcrum.

As described above, in the roller rocker arm (R) of this embodiment, the shaft protruding from one side surface of the rocker arm body (1) pivotally supported by the cylinder head (2).
A roller (10), which is adapted to rotate in contact with the rotating cam (13), is pivotally fitted to (9), that is, the roller (10)
The shaft (9) is cantilevered to the rocker arm body (1), so that the assembly and replacement of the roller (10), maintenance, etc. are facilitated, and the rocker arm body (1)
Can be easily manufactured, and the manufacturing cost can be reduced.

[0017]

According to the present invention, the following effects can be obtained. (a) Since the roller shaft is cantilevered on the side of the rocker arm main body, the roller can be easily assembled or replaced from the side of the rocker arm main body, and
Easy maintenance. (b) The rocker arm body does not need to be perforated for accommodating the rollers, and can be easily manufactured by cold sweat forging of the square material. (c) Due to the effects of (a) and (b), the manufacturing cost can be reduced. (d) on one side of the rocker arm main body, a recess, and fitting pivot the roller into the recess, and the center of the pivot portion of the rocker arm main body to the cylinder head, the center of the roller, the rocker arm body and the engine valve since the center of the contact portion is disposed in a straight line, the dynamic balance of the rocker arm main body at the time of engine operation is not good.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention and a mounting example thereof.

FIG. 2 is a plan view taken along line AA of FIG.

FIG. 3 is also a perspective view of only a rocker arm main body.

[Explanation of symbols]

(1) Rocker arm body (1a) Spherical hole (2) Cylinder head (3) Valve lash adjuster (3a) Pivot shaft (3b) Spherical part (4) Cotta (5) Spring retainer (6) Valve spring (7) Engine valve (8) Recess (9) Shaft (9a) Large diameter flange (9b) Large diameter shaft (9c) Small diameter shaft (10) Roller (11) Shaft hole (12) Snap ring (13) Rotating cam (R) Roller rocker arm (L) Straight line (O1) Center of pivot of rocker arm body (O2) Center of roller (O3) Center of abutting part between rocker arm body and engine valve

Claims (1)

(57) [Claims] 1. A cylinder head which is pivotally supported by another part.
Rocker arm that pushes the engine valve
A recess is formed on one side of the rocker arm body,
In the recess, the shaft protruding from the rocker arm body
Pivot a roller that rotates in contact with the rolling cam
At the same time, pivot the rocker arm body to the cylinder head
Part center, roller center, rocker arm body and engine
The center of the contact part with the gin valve is
And a roller rocker arm.