JP3385341B2 - Rocker arm and method of manufacturing rocker arm body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rocker arm for opening and closing a valve provided in a cylinder head in response to a sliding motion by a cam, and more particularly to a rocker arm body made of a metal plate.

[0002]

2. Description of the Related Art As a rocker arm made of sheet metal of this type,
For example, there is one as shown in FIGS. In the figure,
Reference numeral 1 is a cam portion of a cam shaft, 2 is a valve stem portion, 3 is a lash adjuster pivot portion, and 4 is a rocker arm.

The rocker arm 4 has a structure in which a roller 6 is rotatably attached to a rocker arm body 5. The rocker arm main body 5 is manufactured by metal-forming a metal plate into a substantially gate shape, and includes two pairs of roller support wall portions 7 and 8 facing each other in parallel and both roller support wall portions 7 and 8. And a connecting portion 10 having a rectangular through hole 9 in the middle in the longitudinal direction. A valve engaging portion 11 is formed on one end side in the longitudinal direction of the connecting portion 10, and a substantially hemispherical pivot engaging portion 12 is formed on the other end side in the longitudinal direction of the connecting portion 10. The cam portion 1 is brought into contact with the roller 6 projecting from the through hole 9 of the rocker arm body 5, and the valve engaging portion 1
The valve stem portion 2 is brought into contact with 1, and the pivot portion 3 of the lash adjuster is engaged with the pivot engaging portion 12.

The pair of roller support walls 7 and 8 of the rocker arm body 5 are formed with shaft insertion holes 14 and 14, respectively, and the shaft 1 is inserted into the shaft insertion holes 14 and 14.
When both ends of the shaft 3 are fitted, both ends of the shaft 13 are fixed by being caulked to the outer opening end edges of the shaft insertion holes 14 of the roller support wall parts 7 and 8. A roller 6 is rotatably fitted and supported at the center of the shaft 13 in the axial direction.

[0005]

By the way, the inner surface 11a of the valve engaging portion 11 of the rocker arm body 5 is in sliding contact with the upper end surface of the valve stem portion 2 at high speed.
Since this rocker arm 4 is used in an environment in which the lubricating oil is thin at high temperature, the lubricating oil film on the valve sliding contact surface 11a is likely to be discontinued and seized easily.

The present invention was devised in view of such circumstances, and an object thereof is to prevent seizure by forming a lubricating oil film on the valve sliding contact surface of the valve engaging portion without interruption. And

[0007]

According to the present invention, a rocker arm body made of sheet metal is provided between a pair of roller supporting wall portions on both sides of a connecting portion so as to face each other substantially in parallel, and between the roller supporting wall portions. A rocker arm having a roller rotatably attached has the following configuration.

In the rocker arm of the present invention, the rocker arm main body is manufactured by forming a metal plate into a substantially U shape, and connects the roller support wall portion and the roller support wall portions with each other at an intermediate position in the longitudinal direction. and a connecting portion through holes which the rollers protrude are formed, one longitudinal end of the connecting portion, by forming the metal plate into substantially U-shape, length so that the valve stem abuts
The valve engaging portion is formed in a substantially U-shape that is opened in the hand direction, and this valve engaging portion has a flat valve sliding contact surface with which the valve stem portion is in sliding contact. A lubricating oil sump is provided which is composed of a plurality of small recesses that do not penetrate in the thickness direction of the metal plate .

In the rocker arm body of the rocker arm having such a structure, one metal plate is punched into a predetermined shape by a punching die, and the roller supporting wall is connected by a convex portion provided in the punching die. a part on the surface of the valve sliding surface, the metal plate thickness direction
Transfer the lubricating oil sump consisting of a number of small recesses that do not penetrate, and squeeze the punched metal plate into a substantially U-shape so that the roller support walls face each other in parallel on both sides of the connecting part. It is manufactured by a step of forming, a step of forming a through hole through which the roller protrudes in the connecting portion, and a step of forming a shaft insertion hole for inserting a roller supporting shaft in the roller supporting wall portion.

Alternatively, the valve sliding contact surface of a single metal plate
Penetrating the metal plate thickness direction by embossing to the surface comprising
A step of punching out the steps of lubricating oil reservoir transcription formation composed of a plurality of small recesses, portions forming a plurality of recesses by punching mold the metal plate to couple the roller support wall portion at one end which is not, the Forming a punched metal plate into a substantially U-shape so that the pair of roller supporting wall portions face each other on both sides of the connecting portion substantially in parallel; and forming a through hole through which the roller protrudes in the connecting portion. It is manufactured by a step and a step of forming a shaft insertion hole for inserting a shaft for supporting a roller in the roller supporting wall portion.

[0011]

This type of rocker arm swings up and down about the pivot engaging portion, and its movement causes the inner surface of the valve engaging portion to slide against the surface of the valve stem portion. However, if a lubricating oil sump is provided on the inner surface of this valve engaging portion, that is, on the valve sliding contact surface that is the surface of the valve engaging portion, the lubricating oil that accumulates in the lubricating oil sump due to the sliding operation will contact the valve sliding contact. It is efficiently transferred and supplied to the surface, and the oil film is formed without interruption.
Especially, the lubricating oil reservoir does not penetrate in the thickness direction of the metal plate.
Since it consists of multiple small recesses,
When lubricating oil collects in the
While holding it moderately due to effects such as
Efficiently moving between the two due to the sliding contact with the valve stem.
Will be transferred and supplied.

[0012]

1 and 2 show an embodiment of the present invention. In this embodiment, the same parts and portions as those shown in FIGS. 3 to 6 of the conventional example are designated by the same reference numerals. In the figure,
Reference numeral 1 is a cam portion of a cam shaft, 2 is a valve stem portion, 3 is a lash adjuster pivot portion, and 4 is a rocker arm.

The rocker arm 4 has a structure in which a roller 6 is rotatably attached to a rocker arm main body 5, and the basic structure is almost the same as the conventional example. The rocker arm body 5 is
It is manufactured by metal-forming a metal plate into a substantially U-shape, and connects two pairs of roller supporting wall portions 7 and 8 that face each other substantially in parallel and both roller supporting wall portions 7 and 8 and connects them in the longitudinal direction. A connecting portion 10 having a rectangular through hole 9 is provided in the middle. A valve engaging portion 11 is formed on one end side in the longitudinal direction of the connecting portion 10, and a substantially hemispherical pivot engaging portion 12 is formed on the other end side in the longitudinal direction of the connecting portion 10. The cam portion 1 is brought into contact with the roller 6 protruding from the through hole 9 of the rocker arm body 5, the valve stem portion 2 is brought into contact with the valve engaging portion 11, and the lash adjuster of the lash adjuster is attached to the pivot engaging portion 12. The pivot part 3 is engaged.

The pair of roller support walls 7 and 8 of the rocker arm body 5 are formed with shaft insertion holes 14 and 14, respectively, and the shaft 1 is inserted into the shaft insertion holes 14 and 14.
Both end portions of 3 are shaft insertion holes 14 of both roller support wall portions 7 and 8,
It is fixed by being caulked to the outer opening edge of 14. A roller 6 is rotatably fitted and supported at an intermediate position in the axial direction of the shaft 13.

The feature of this embodiment is that a plurality of recesses 15 are provided as a reservoir of lubricating oil on the valve sliding contact surface 11a of the valve engaging portion 11 of the rocker arm body 5.
Even if the lubricating oil in the operating environment of the rocker arm 4 is thin,
During the sliding contact between the valve sliding contact surface 11a of the valve engaging portion 11 and the valve stem portion 2, the lubricating oil accumulated in the recess 15 is drawn out and transferred to the valve sliding contact surface 11a. An oil film is formed on the valve sliding contact surface 11a. Further, the excess lubricating oil on the valve sliding contact surface 11a is returned to the recess 15 again by the sliding contact operation. In this way, the operation of supplying the lubricating oil is efficiently repeated in all the recesses 15, so that the lubricating oil film can be formed on the valve sliding contact surface 11a of the valve engaging portion 11 without interruption.

The rocker arm body 5 is punched out from a single metal plate into a shape as shown in FIG. 2 and drawn. Then, the through hole 10 and the shaft insertion holes 14 and 14 of the roller support wall portions 7 and 8 are formed. It is manufactured by forming. The concave portion 15 of the valve sliding contact surface 11a of the valve engaging portion 11 is transferred and formed simultaneously with the punching by providing a convex portion corresponding to the concave portion 15 in the punching die at the time of punching. Of course, the plurality of recesses 15 may be formed by stamping before the above-mentioned punching.

The present invention is not limited to the above embodiment. For example, the overall shape of the rocker arm body 5 is arbitrary, and a plurality of needle rollers may be interposed between the roller 6 and the shaft 13. Further, the valve engaging portion 11 may be formed separately from the rocker arm body 5 and integrally coupled to the rocker arm body 5, and the present invention is also included in the present invention. Further, the concave portion 15 as a lubricating oil reservoir
May be formed by forming a knurled pattern or a groove having an appropriate pattern.

[0018]

As described above, according to the present invention, as the valve sliding contact surface of the valve engaging portion and the valve stem portion slide in contact with each other, the lubricating oil is collected from the lubricating oil reservoir on the valve sliding contact surface to the surface side. Therefore, the oil film can be formed seamlessly at the sliding contact portion between the valve sliding contact surface and the upper end surface of the valve stem portion. Therefore, even if the lubrication condition of the operating environment of the rocker arm is bad, the lubricated / cooled state of the sliding contact portion is always maintained in a good condition, which makes it difficult to seize and contributes to the improvement of life.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a rocker arm of the present invention.

FIG. 2 is a plan view of the rocker arm main body of the rocker arm before sheet metal.

FIG. 3 is a side view showing a usage state of a conventional sheet metal rocker arm.

FIG. 4 is a perspective view of the rocker arm of FIG.

FIG. 5 is a vertical sectional view taken along the longitudinal direction of the rocker arm.

FIG. 6 is a vertical sectional view taken along the width direction of the rocker arm.

[Explanation of symbols]

1 cam part 2 Valve stem part 3 Pivot part of lash adjuster 4 rocker arms 5 Rocker arm body 6 roller 7,8 Roller support wall 10 connection 11 Valve engaging part 11a Valve sliding contact surface 12 Pivot engagement part 15 recess

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-231610 (JP, A) JP-A-63-75305 (JP, A) Actually open 2-87911 (JP, U) Actually open-Sho 60- 131604 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F01L 1/18

Claims (3)

(57) [Claims] 1. A rocker arm main body made of sheet metal, which is provided on both sides of a connecting portion so that a pair of roller supporting wall portions are opposed to each other substantially in parallel, and a roller rotatably mounted between the roller supporting wall portions. A rocker arm having, wherein the rocker arm main body is manufactured by forming a metal plate into a substantially U shape, and connects the roller support wall portion and the roller support wall portions to each other in the longitudinal intermediate position, and the roller is A connecting portion having a through hole protruding is formed, and one end side in the longitudinal direction of the connecting portion is opened in the longitudinal direction so that the valve stem portion abuts by forming the metal plate in a substantially U shape . is a valve engaging portion formed in the substantially C-shape, the valve engagement portion has a flat-shaped valve sliding surface of the valve stem sliding contact, in the valve sliding surface, gold Lubricating oil sumps formed of a plurality of small recesses which does not penetrate in the thickness direction is provided, the rocker arm, characterized in that. 2. A pair of roller supporting wall portions are provided on both sides of the connecting portion so as to face each other substantially in parallel and are opened in the longitudinal direction.
A method of manufacturing the rocker arm body in a rocker arm having a substantially U-shaped rocker arm body made of sheet metal and a roller rotatably mounted between the roller supporting wall parts, wherein a metal plate is punched out. The die is punched into a predetermined shape, and the convex portion provided on the punching die serves as a connecting portion of the roller support wall portion and a valve sliding contact surface.
The front surface, forming transfer the lubricating oil sump consisting of a plurality of small recesses which does not penetrate to the metal plate thickness direction, so that the roller support wall on both sides of the connecting portion is opposed in substantially parallel, metal plate after punching Is formed into a substantially U-shape, a step of forming a through hole through which the roller protrudes is formed in the connecting portion, and a shaft insertion hole for inserting a shaft for supporting the roller is formed in the roller support wall portion. A method of manufacturing a rocker arm body, comprising: 3. A pair of roller supporting wall portions are provided on both sides of the connecting portion so as to face each other substantially in parallel and are opened in the longitudinal direction.
A method of manufacturing the rocker arm body in a rocker arm having a substantially U-shaped sheet metal rocker arm body and a roller rotatably mounted between the roller supporting wall portions, comprising a valve slide of a single metal plate. and transferring forming a lubricating oil sump consisting of a plurality of small recesses which does not penetrate to the metal plate thickness direction by embossing on the table surface comprising a contact surface, portions forming a plurality of recesses of the roller support wall Punching the metal plate with a punching die so as to connect at one end side, and squeezing the punched metal plate into a substantially U-shape so that the pair of roller supporting wall parts face each other on both sides of the connecting part substantially in parallel. A step of forming, a step of forming a through hole through which the roller protrudes in the connecting portion, and a step of forming a shaft insertion hole into which the roller supporting shaft is inserted in the roller supporting wall portion. Method of manufacturing a rocker arm main body, wherein the having it and.