JPS6330874Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mounting structure for a cylinder head cover of an internal combustion engine, and more particularly to a mounting structure for a cylinder head cover in an internal combustion engine having a plug tube for inserting a spark plug.

BACKGROUND OF THE INVENTION In internal combustion engines for automobiles, the amount of oil splashed inside the cylinder head cover is relatively large due to reasons such as higher speed and higher performance, and oil leakage from tightening parts often becomes a problem. Furthermore, the transmission of noise caused by the valve train (particularly in the case of an overhead camshaft type) is also a major problem. Conventionally, therefore, a gasket has been used as an oil seal for the mating surfaces of the cylinder head cover and the cylinder head, and surface sealing has been achieved by applying surface pressure as uniformly as possible to the gasket by tightening the head cover. The conventional technique for attaching the cylinder head cover to the cylinder head is to erect several stud bolts from the top of the cylinder head and tighten the head cover with nuts (for example,
(Refer to Utility Model Application No. 54-31716). A structure in which the cylinder head cover is supported via a rocker support is also known (see, for example, Japanese Utility Model Application No. 153107/1983).

However, with the recent trend of downsizing and four-valve engines, it may not be possible to provide a boss for installing the stud bolt on the top surface of the cylinder head, and the bolts must be tightened around the cylinder head cover. In the case of peripheral tightening like this,
Naturally, it will be tightened at multiple points, and due to variations in the tightening torque, it will be very difficult to equalize the surface pressure of the cylinder head cover.

Incidentally, an internal combustion engine having a plug tube and having a seal packing between the plug tube and the cylinder head cover is disclosed in US Pat. No. 3,144,013.

Problems to be Solved by the Invention The invention provides a simple structure for mounting the cylinder head cover in an internal combustion engine having a plug tube so that the surface pressure on the mating surfaces of the cylinder head cover and the cylinder head is uniform. This is what we are trying to provide.

Means for Solving the Problems According to the present invention, a plug hole for installing a spark plug is formed in the cylinder head, a plug tube is attached to the plug hole, and the cylinder head cover is connected to the cylinder via a gasket. In a cylinder head cover mounting structure for an internal combustion engine that comes into contact with a head, the plug tube has male threads at both ends, one end of which is screwed into a female thread formed in the plug hole, and the other end is used to attach the cylinder head cover. A structure is provided in which the cylinder head cover is attached to the cylinder head by protruding from the hole and tightening a nut through a sealing grommet on the protrusion.

Embodiment The figure shows an embodiment of the cylinder head cover mounting structure for an internal combustion engine according to the present invention. In the figure, 1 is a plug tube, 2 is a spark plug, 3 is a cylinder head, 4 is a combustion chamber, 5 is a cooling water jacket, 6 is an intake port, and 7 is an exhaust port. However, intake and exhaust valves and their valve seats are not shown.

In order to install the spark plug 2, a plug hole 9 is bored in the cylinder head 3, and the upper part of the plug hole 9 is formed with a female threaded portion 9a. On the other hand, a plug tube 1 formed of a pipe or the like has male threaded portions 1a and 1b formed on the outer periphery of both ends thereof, and one end 1a of the plug tube 1 is formed with male threads 1a and 1b.
is screwed into the female threaded portion 9a of the plug hole 9 and fixed. The inner diameter (φD) of the plug tube 1 is such that a plug tightening tool (not shown) for attaching and detaching the ignition plug 2 can be inserted therein.

A sealing gasket 11 is installed around the cylinder head cover 8, and a mounting hole 12 is provided in the upper part at a position corresponding to the plug tube 1.
have. There are four mounting holes 12 in the case of a four-cylinder engine, and six in the case of a six-cylinder engine. When the cylinder head cover 8 is attached to the cylinder head 3 so that the mounting hole 12 is fitted into the plug tube 1, the gasket 11 comes into contact with the upper surface of the cylinder head 3, and the upper end 1b of the plug tube 1 is placed above the mounting hole 12. stand out.

Next, insert the grommet 13 into the plug tube 1 from above to seal the gap between the plug tube 1 and the cylinder head cover 8, and then tighten the tightening nut 1.
4 into the male threaded portion 1b at the upper end of the plug tube 1. The grommet 13 has a structure in which a rubber lip 13a for sealing is vulcanized and bonded to a metal ring 13b for fixing.

Effects of the invention According to the invention, the cylinder head cover 8 is attached to the cylinder head 3 by tightening at four places (in the case of a four-cylinder engine) or six places (in the case of a six-cylinder engine) on its upper surface. As described above, it has been known that tightening the top surface of the cylinder head cover is more effective in achieving uniform surface pressure contact in the gasket 11 than tightening around the circumference. 8 can be realized with a simple structure using the plug tube 1. In other words, even in cases where it is not possible to install stud bolt bosses for cover attachment on the top surface of the cylinder head due to the downsizing of engines and the use of four valves, it is possible to tighten the top surface as described above. be.

[Brief explanation of the drawing]

The figure is a sectional view of a cylinder head portion of an internal combustion engine employing the cylinder head cover mounting structure of the present invention. 1...Plug tube, 2...Spark plug, 3
... Cylinder head, 8 ... Cylinder head cover, 9 ... Plug hole, 11 ... Gasket,
12...Mounting hole, 13...Seal grommet,
14... Tightening nut.

Claims (1)

[Scope of utility model registration request] Plug hole 9 for installing spark plug 2
In the cylinder head cover mounting structure for an internal combustion engine, the cylinder head cover 8 is provided in the cylinder head 3, the plug tube 1 is mounted in the plug hole 9, and the cylinder head cover 8 is brought into contact with the cylinder head 3 via the gasket 11. Plug tube 1
has male threads 1a and 1b at both ends, and one end 1
a female threaded portion 9a formed in the plug hole 9;
and screw the other end 1b into the cylinder head cover 8.
The cylinder head cover is attached to the cylinder head by protruding from the mounting hole 12 of the cylinder head and tightening a nut 14 through a sealing grommet 13 to the protrusion 1b.