JPH05948U - Lock cover - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the flatness of the oil seal seating surface formed around the plug hole of the rocker cover. An oil seal attached to the upper end of a plug guide, which is attached to a cylinder head and has a plug hole at a predetermined position on the upper surface, and a base end of which is fitted into a plug mounting hole of a combustion chamber of the cylinder head, is the plug. In the rocker cover that abuts the peripheral edge of the hole, the peripheral edge of the plug hole 5b is punched out to form the oil seal seat surface 5d.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rocker cover attached to a cylinder head.

[0002]

[Prior Art]

 As shown in FIG. 4, the cylinder head 1 of the engine has a combustion chamber 1b on the bottom surface, an intake port 1c and an exhaust port 1d communicating with the combustion chamber 1a on the side, and a valve operating mechanism ( (Not shown) is provided and mounted and fixed on a cylinder block (not shown). The rocker cover 2 is attached to the cylinder head 1 so as to cover the valve mechanism in a liquid-tight manner. The rocker cover 2 has a plug hole 2b (FIGS. 4 and 5) for inserting a plug (not shown) at a predetermined position on the upper surface 2a corresponding to the combustion chamber of each cylinder.

The plug guide 3 has a cylindrical shape, and a base end 3a is liquid-tightly fitted in a plug mounting hole 1e formed in an upper wall of a combustion chamber of the cylinder head 1, and an oil seal 4 is provided in an upper end 3b. It is installed. Then, the upper end 3b of the plug guide 3 is liquid-tightly contacted with the peripheral edge (hereinafter referred to as "seat surface") 2c of the plug hole 2b on the inner surface of the rocker cover 2 through the oil seal 4, thereby operating the valve mechanism. The oil that sometimes scatters is prevented from leaking out of the rocker cover 2. Therefore, it is indispensable that the oil seal 4 closely contacts the seat surface 2c of the plug hole 2b very well.

[0004]

[Problems to be solved by the device]

 However, since the conventional rocker cover 2 is formed by forming the plug hole 2b at a predetermined position on the upper surface 2a after molding the whole, the seating surface 2c at the peripheral edge of the plug hole 2b is apt to wavy and is flat. It is hard to get a degree. Therefore, the mist-like oil scattered in the rocker cover 2 may leak to the outside through a slight gap between the seat surface 2c of the plug hole 2b and the oil seal 4, and the leaked oil may leak to the plug guide. If it accumulates in the plug 3, it may cause an abnormality in the plug, and there is a problem that the consumption of engine oil will increase.

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

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, a plug guide is attached to a cylinder head, and a plug hole is formed at a predetermined position on the upper surface, and a base end is fitted into a plug mounting hole of a combustion chamber of the cylinder head. In the rocker cover in which the oil seal attached to the upper end of the plug abuts the peripheral edge of the plug hole, the peripheral edge of the plug hole is punched out to form the oil seal seat surface.

[0007]

[Action]

 The rocker cover has an extremely high flatness because the oil seal seating surface around the periphery of the plug hole is formed by stamping, and the rocker cover is in excellent contact with the oil seal mounted on the upper end of the plug guide. This prevents the atomized oil in the rocker cover from leaking to the outside. Moreover, the rigidity of the rocker cover is improved by punching out the peripheral edge of the plug hole to form the oil seal seat surface.

[0008]

【Example】

 An embodiment of the present invention will be described in detail below 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), and an upper surface 5a has a lower end of the combustion chamber of each cylinder of the cylinder head. A plug hole 5b is formed so as to oppose the upper end position of each plug guide 3 that is installed in a plug installation hole (not shown) formed in the upper wall. The open end 5c (FIG. 2) of the plug hole 5b is extruded outward to form a flange so that a plug cap (not shown) can be attached.

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

The depth of the punched oil seal seat surface 5d is, for example, about the plate thickness of the rocker cover 5, and the inner diameter thereof 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 out the peripheral edge of the plug hole 5b, the flatness of the upper surface 5a of the rocker cover 5 is low in accuracy, and it seems to be wavy. Even in the state, the flatness can be made extremely high. After forming the oil seal seat surface 5d, for example, the flange 5e at the lower end is bent.

The operation will be described below. The rocker cover 5 liquid-tightly covers a valve mechanism (both not shown) mounted on the cylinder head and arranged above the cylinder. The oil seals 4 mounted on the upper ends 3b of the plug guides 3 whose base ends are liquid-tightly fitted in the plug mounting holes of the combustion chambers of the cylinder head are respectively attached to the corresponding plug holes. The oil seal bearing surfaces 5d on the periphery of 5b are brought into liquid-tight contact with each other. The flatness of the oil seal seating surface 5d of the plug hole 5b is formed with extremely high precision, and therefore the oil seal 4 closely contacts the oil seal seating surface 5d. As a result, liquid tightness between the oil seal seat surface 5d of the rocker cover 5 and the oil seal 4 is secured.

When the valve operating mechanism operates as the engine moves, the oil supplied to the valve operating mechanism is scattered and atomized to fill the rocker cover 5. The filled mist-like 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 blocked 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 with a concave shape formed by locally forcibly punching out the peripheral edge of each plug hole 5d, so that the rocker cover 5 has a structure as compared with a rocker cover having a conventional structure. And the rigidity becomes higher. As a result, when the rocker cover 5 is mounted on the cylinder head, vibration noise generated due to engine vibration is reduced.

[0014]

[Effect of the device]

 As described above, according to the present invention, the plug head is attached to the cylinder head, the plug hole is formed at a predetermined position on the upper surface, and the base end is fitted to the upper end of the plug guide fitted into the plug mounting hole of the combustion chamber of the cylinder head. In the rocker cover where the mounted oil seal comes into contact with the peripheral edge of the plug hole, the peripheral edge of the plug hole is punched out to form the oil seal seat surface, so that the flatness of the oil seal seat surface is increased. This makes it possible to improve the adhesion with the oil seal, prevent oil leakage inside the rocker cover, and improve reliability. In addition, the rigidity of the entire rocker cover is increased, and vibration noise due to engine vibration can be reduced.

[Brief description of 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 of the vicinity of the plug hole in FIG.

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

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

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

[Explanation of symbols]

 1 Cylinder head 3 Plug guide 4 Oil seal 5 Rocker cover 5b Plug hole 5d Oil seal bearing surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Kawakami 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation

Claims (1)

[Claims for utility model registration] 1. A plug guide which is attached to a cylinder head and has a plug hole formed at a predetermined position on the 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 in which an oil seal mounted on an upper end abuts on the peripheral edge of the plug hole, wherein the peripheral edge of the plug hole is punched out to form an oil seal seat surface.