JP2554436Y2 - Rocker cover - 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 cover mounted on a cylinder head.

[0002]

2. Description of the Related Art As shown in FIG. 4, a cylinder head 1 of an engine has a combustion chamber 1b on the bottom and a combustion chamber 1a on a side.
An intake port 1c and an exhaust port 1d are formed, and a valve mechanism (not shown) is provided on the upper part, and is mounted and fixed on a cylinder block (not shown). The rocker cover 2 is mounted on the cylinder head 1, and covers the valve mechanism in a liquid-tight manner. The rocker cover 2 has a plug hole 2b for inserting a plug (not shown) at a predetermined position corresponding to the combustion chamber of each cylinder on the upper surface 2a.
(FIGS. 4 and 5) are drilled.

The plug guide 3 has a cylindrical shape and a base end 3a.
Are fitted in a plug mounting hole 1e formed in the upper wall of the combustion chamber of the cylinder head 1 in a liquid-tight manner, and an oil seal 4 is mounted on the upper end 3b. The upper end 3b of the plug guide 3 is brought into liquid-tight contact with a peripheral edge (hereinafter, referred to as a "seat surface") 2c of the plug hole 2b on the inner surface of the rocker cover 2 via the oil seal 4, and when the valve operating mechanism operates. The scattered oil is prevented from leaking out of the rocker cover 2. Therefore, it is indispensable that the oil seal 4 adheres very well to the bearing surface 2c of the plug hole 2b.

[0004]

However, since the conventional rocker cover 2 is formed by forming a plug hole 2b at a predetermined position on the upper surface 2a after molding the entirety, the peripheral edge of the plug hole 2b is inevitably formed. Of the seat surface 2c is easy to undulate, and the flatness is hardly obtained. For this reason, the mist oil scattered in the rocker cover 2 may leak to the outside through a slight gap between the bearing surface 2c of the plug hole 2b and the oil seal 4, and the leaked oil may be plugged. If it accumulates in the guide 3, it may cause an abnormality in the plug, and there is a problem that the consumption of engine oil becomes severe.

The present invention has been made in view of the above points, and has been made to improve the flatness of a seat surface of an oil seal in a plug hole of a rocker cover to improve the adhesion of a plug guide to an oil seal. It is intended to provide a rocker cover.

[0006]

According to the present invention, in order to achieve the above object, according to the present invention, a plug hole is formed at a predetermined position on an upper surface of a cylinder head, and a base end is provided with a plug for a combustion chamber of a cylinder head. In a rocker cover in which an oil seal mounted on an upper end of a plug guide fitted into the hole is in contact with a peripheral edge of the plug hole, an oil seal seating surface is formed by projecting a peripheral edge of the plug hole. .

[0007]

The rocker cover has an extremely high flatness due to the formation of the oil seal seating surface at the periphery of the plug hole by stamping, so that the rocker cover adheres very well to the oil seal mounted on the upper end of the plug guide. This prevents the mist oil in the rocker cover from leaking to the outside. In addition, the rigidity of the rocker cover is improved by forming the oil seal seat surface by punching out the peripheral edge of the plug hole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, a rocker cover 5 is, for example, a rocker cover mounted on a cylinder head of an engine having a single overhead cam (SOHC).
In the figure, a lower end of each plug guide 5 is opposed to an upper end position of each plug guide 3 mounted in a plug mounting hole (not shown) formed in an upper wall of a combustion chamber of each cylinder of the cylinder head.
b is drilled. Open end 5c of this plug hole 5b
(FIG. 2) is pushed outward to form a flange, and a plug cap (not shown) is mounted thereon.

The peripheral edge 5d of each of the plug holes 5b on the inner surface 5a 'of the rocker cover 5 is formed into a circular shape that is stamped outward from the inside and is one step lower than the inner surface 5a' when viewed from the inside. The peripheral edge 5d is an oil seal seat surface (hereinafter, referred to as "oil seal seat surface 5d"). The rocker cover 5 is formed of a thin iron plate. After the entire shape is formed by press molding, a plug hole 5b is formed at a predetermined position on the upper surface 5a, and each of the plug holes 5b is formed by press molding. The peripheral edge is stamped out from the inner surface 5a 'side to form the oil seal seat surface 5d.

The depth of the stamped oil seal seat surface 5 d is, for example, about the plate thickness of the rocker cover 5, and its inner diameter is slightly larger than the outer diameter of the oil seal 4. ing. Since the oil seal seat surface 5d is formed by locally and forcibly punching the periphery of the plug hole 5b, the accuracy of the flatness of the upper surface 5a of the rocker cover 5 is low, and the oil seal seat surface 5d has a wavy shape. Even in this state, the flatness can be formed extremely high. After forming the oil seal seat surface 5d, for example, the lower end flange 5e
Is performed.

The operation will be described below. Rocker cover 5
Covers a valve mechanism (both not shown) mounted on the cylinder head and mounted on the cylinder head in a liquid-tight manner. Each plug guide 3 whose base end is fitted in a plug mounting hole of each combustion chamber of the cylinder head in a liquid-tight manner.
Each of the oil seals 4 attached to the respective upper ends 3b is in liquid-tight contact with an oil seal seat surface 5d on the periphery of the corresponding plug hole 5b. Oil seal seat surface 5 of plug hole 5b
As for d, the flatness thereof is formed with extremely high precision, so that the oil seal 4 is in very good contact with the oil seal seat surface 5d. Thereby, liquid tightness between the oil seal seat surface 5d of the rocker cover 5 and the oil seal 4 is ensured.

When the valve operating mechanism operates with the operation of the engine, the oil supplied to the valve operating mechanism scatters and becomes mist, and fills the inside of the rocker cover 5. The mist-filled oil reaches the contact portion between the oil seal 4 at the upper end of the plug guide 3 and the oil seal seat surface 5d of the rocker cover 5, but is completely shut off by the contact portion. This prevents the oil from leaking out of the rocker cover 5.

The rocker cover 5 has an oil seal seat surface 5d having a one-step recessed shape formed by forcibly punching out the periphery of each plug hole 5d locally so that the rocker cover has a conventional structure. Rigidity increases. As a result, when the rocker cover 5 is mounted on the cylinder head, vibration noise generated due to engine vibration is reduced.

[0014]

As described above, according to the present invention, a plug hole is formed at a predetermined position on the upper surface of the cylinder head, and the base end is fitted into the plug mounting hole of the combustion chamber of the cylinder head. In the rocker cover in which the oil seal mounted on the upper end of the plug guide is in contact with the peripheral edge of the plug hole, the peripheral edge of the plug hole is punched out to form an oil seal seat surface. As a result, the degree of adhesion with the oil seal is improved, oil leakage in the rocker cover can be prevented, and reliability is improved. In addition, the rigidity of the entire rocker cover is increased, and there is an effect that vibration noise caused by engine vibration is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a rocker cover to which the present invention is applied.

FIG. 2 is an enlarged view near a plug hole in FIG. 1;

FIG. 3 is a partial end view as viewed from the direction of arrow III in FIG. 1;

FIG. 4 is a sectional view of a cylinder head to which a conventional rocker cover is applied.

FIG. 5 is a partial end view seen from the direction of arrow V in FIG. 4;

[Explanation of symbols]

 1 Cylinder Head 3 Plug Guide 4 Oil Seal 5 Rocker Cover 5b Plug Hole 5d Oil Seal Seat

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noboru Kawakami 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (56) References Reference

Claims (1)

(57) [Scope of request for utility model registration] An oil seal mounted on an upper end of a plug guide which is mounted on a cylinder head and has a plug hole formed at a predetermined position on an upper surface and a base end of which is fitted into a plug mounting hole of a combustion chamber of the cylinder head. A rocker cover, wherein an oil seal seat surface is formed by punching out a periphery of the plug hole in a rocker cover abutting on a periphery of the plug hole.