JP3055003B2 - Oil hole bead - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bead for an oil hole, and more particularly to a bead for sealing provided in an oil hole of a cylinder head gasket made of a thin metal plate.

[0002]

2. Description of the Related Art A cylinder head gasket provided between a cylinder head and a cylinder body of an internal combustion engine includes a cylinder hole forming a combustion chamber, lubricating oil, cooling water,
A large number of various holes through which a head bolt, a push rod and the like pass are provided. With the increase in engine output, metal gaskets made of thin metal plates have been widely used in gasoline engines as well as diesel engines, which are generally used for high output.

[0003] A metal gasket seal is usually provided around a hole to be sealed, and provided with a bead obtained by expanding a metal plate in a loop shape, and the reaction force generated when the gasket is tightened to compress the bead is used to seal the metal gasket. The gap between the boards is pressed against the deck surface to seal. As is well known, cylinder holes are arranged in a horizontal line on a joint surface between a cylinder head and a cylinder body of a multi-cylinder in-line type internal combustion engine, and the various holes are arranged around the cylinder holes. Then, the head bolt is placed around the cylinder
Because it is arranged to exert a more uniform tightening force,
A liquid hole such as an oil hole or a water hole is located at a position eccentric with respect to the head bolt, and there is a problem that it is difficult to uniformly tighten a bead provided in the liquid hole.

Further, in order to reduce the weight of the engine to achieve high output,
In recent years, cylinder heads made of aluminum alloy have been used. Therefore, the cylinder head receives the reaction force of the bead, and is likely to receive a deformation force in which the central portion is warped, and the tightening force of the bead provided in the liquid hole tends to be more non-uniform. By the way, the oil passage is provided for lubrication of a valve operating mechanism provided at an upper portion of the cylinder head, and since there are few portions directly related to the cylinder body and the cylinder head, the oil passage has conventionally been protruded from a corner portion of the engine or a main body. It is often provided in the part where it was provided. Therefore, the tendency that the tightening force by the head bolt becomes uneven becomes more remarkable than that of the water hole.

Therefore, the oil passage is arranged near the head bolt so that the bolt tightening force can be easily applied. Therefore, the oil hole bead of the cylinder head gasket is formed as follows.
Conventionally, a bead for an oil hole is formed so as to surround the bolt hole so as not to interfere with the bolt hole. In order to improve the sealing performance by the common bead, the present applicant has devised the spring constant of the bead to be smaller on the oil hole side than on the bolt hole side (see Japanese Utility Model Application Laid-Open No. HEI 2-102).
No. 101061).

[0006]

As is well known, internal combustion engines, especially internal combustion engines for automobiles, are demanded from the market to pursue higher performance, and are constantly being improved. As a result, higher performance has been required for the seal of the oil hole of the cylinder head gasket.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. In a metal cylinder head gasket in which an oil hole bead is formed integrally with a bolt hole bead, an oil hole having further improved sealing performance is provided. It is an object of the present invention to provide a bead.

[0008]

According to a first aspect of the present invention, there is provided a bead for an oil hole, comprising: an oil passage extending from a cylinder body to a cylinder head; Forming an oil hole and a bolt hole for the head bolt, forming a bead surrounding these holes by one trapezoidal bead common to both holes, and forming a cross-sectional shape in the width direction of the bead.
The rising angle of the bolt hole side is smaller than the rising angle of the oil hole, and the top width of the bolt hole side is formed smaller than the top width of the oil hole side. Further, a second configuration of the oil hole bead of the present invention for achieving the above object,
An oil passage for the oil passage and a bolt hole for the head bolt are formed in a metal cylinder head gasket of an internal combustion engine in which an oil passage leading from the cylinder body to the cylinder head is formed on the outer peripheral side of the engine near the head bolt, a bead surrounding the periphery of the holes, are common to both holes formed by a circle arc-shaped beads, a widthwise sectional shape of the bead, the rise angle of the bolt hole side than the rise angle of the oil holes side It is small and the top curvature on the bolt hole side is smaller than the top curvature on the oil hole side.

As means for forming the top of the bead on the oil hole side to be wider than the top on the bolt hole side,
The bead width and the bead height can be fixed, and the bead rising angles on both sides in the bead width direction can be adjusted. However, the present invention is not limited thereto, bead width, trapezoidal
It can also be done by other means, such as changing the top width of the shape, the top curvature of the corrugated or arc bead, the bead height.

There is no particular limitation on the change between the top shape and the rising angle of the beads on the oil hole side and the bolt hole side, and they may be changed stepwise. It is preferable to make the change gradually, for example, to make a continuous change between them. Also, the cross-sectional shape of the bead is not particularly limited, but when compressed, the top of the bead on the oil hole side is bent into a valley, so as to be easily inverted W-shaped, so that it is trapezoidal or closer to trapezoidal. It can be shaped.

A single bead surrounds the oil hole and the bolt hole. The cross-sectional shape of the bead in the width direction is such that the rising angle on the oil hole side is larger than the rising angle on the bolt hole side, and the top width on the oil hole side is smaller. The above-mentioned means formed wider than the top width of the bolt hole side easily deforms the bead into an inverted W shape with a lower tightening load, thereby increasing the restoring force and the amount of restoring.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG .
The present invention will be specifically described with reference to embodiments. The oil hole bead 1 of the first embodiment shown in FIGS. 1 and 2 surrounds both an oil hole 3 and a bolt hole 4 formed in a cylinder head gasket (hereinafter simply referred to as a gasket) 2 made of a single plate. It is provided in.

The oil hole 3 is provided on the outer periphery 5 of the gasket 2.
And is located on the opposite side of the cylinder hole 6 with respect to the bolt hole 4. A plurality of bolt holes (not shown except the bolt hole 4) are arranged around the cylinder hole 6. In addition, the code | symbol 7 shown in FIG. 1 is a water hole, 8 is a bead for cylinder holes, and 9 is a bead for water holes.

As shown in FIG. 2, the oil hole bead 1 has a constant trapezoidal shape with a constant bead width W and height h. Then, the rising angle θ ₁ of the bolt hole 4 side A is formed smaller than the rising angle θ ₂ of the oil hole side B (θ ₁ <θ ₂ ), and the width t ₁ of the top of the bolt hole side A is changed to the oil hole side B. Was formed so as to be narrower (width t ₁ <t ₂ ) than the width t ₂ of the top portion of.

The dimensions of each part of the trapezoidal bead are not fixed depending on the specification of the target internal combustion engine. In the case of a normal cylinder head gasket, W is generally 1.5 to 3 mm and h is 0.2 to 1 mm. Note that the symbol w shown in FIG.
₁ represents the overall width of the bead on the bolt hole side, and is shown in FIG.
Code w ₂ is represents the width of the entire bead of oil holes side shown
You. Generally, when a bead having a cross-sectional shape in the width direction such as a waveform or an arc is compressed, the top portion is bent to the opposite side and deformed into an inverted W shape. In the case of the oil hole bead 1 formed as described above, the oil hole is used. since the top portion t ₂ of the 3 side is formed wider easily bent, and easily reversed W-shaped as shown in FIG. When the inverted W shape is further compressed, the deformation proceeds more uniformly over the entire bead width W, and a more uniform reaction force can be obtained than when the rising angle is small . Therefore, the above W and the like are appropriately selected.
By doing so, it is possible to generate a more uniform surface pressure over the entire bead width W with a weaker compressive force. 3 is a cylinder head, 11 is a cylinder body, 12 is a cylinder head 10 and a cylinder body 11.
It is an oil passage drilled in.

On the other hand, on the bolt hole 4 side, when compressed, the width of the top part t ₁ is narrow and the rising angle is small, so that the bead can be easily compressed. By the way, the tightening force of the bolt (not shown) acts more evenly on the cylinder hole 6 side, but the oil hole 3 is in a single tightening state. Further, the operation of the internal combustion engine (not shown) causes the pulsation of the tightening force. The influence of the pulsation is that the pulsation amplitude is larger in the tightening condition of the oil hole side B of the oil hole 3 than in the bolt hole side A.

However, in the oil hole bead 1 of the first embodiment, the outer peripheral 5 side where the tightening force is weak and the pulsation of the tightening force is intense is compressible with the weak tightening force, and is deformed into an inverted W shape. Therefore, expansion and contraction can be easily performed following pulsation, and high sealing performance can be maintained. Embodiment 2 shown in FIG. 4 is a bead 1 for oil hole
Is carried out by a laminated cylinder head gasket 13, the cross section in the width direction is formed into a continuous arc shape, and the beads are formed.
Make the height the same, and the rising slope on the bolt hole 4 side
Oil hole 3 side B steep rising slope and top curve
The ratio is larger on the oil hole side B than on the bolt hole side A. Oil holes for bead 1 of the second embodiment also, the form of embodiment
High sealing performance of same with the oil hole bead 1 of state 1 is obtained. Reference numeral 14 shown in FIG. 4 is a head bolt.

[0018]

As described above, the oil hole bead according to the present invention has a sectional shape in the width direction in which the rising angle on the bolt hole side is smaller than the rising angle on the oil hole side, and the top width on the bolt hole side is reduced by oil. Since it is formed narrower than the top width on the hole side, the entire bead width is more uniformly compressed on the outer peripheral portion of the gasket where a lower compression force acts, generating a wide surface pressure, and following the pulsating compression force High sealing performance could be maintained, and the reliability of the cylinder head gasket could be improved.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a bead for an oil hole according to a first embodiment of the present invention.

2A is a sectional view taken along line IIA-IIA of FIG. 1,
FIG. 2B is a sectional view taken along the line IIB-IIB in FIG.

FIG. 3 is an explanatory view showing a state in which the cross section of the bead shown in FIG. 2 is deformed.

FIG. 4 is a partial sectional view of an oil hole bead according to a second embodiment of the present invention.

[Explanation of symbols]

1 Oil hole bead 2 Gasket (cylinder head gasket) 3 Oil hole 4 Bolt hole 5 Outer circumference 6 Cylinder hole 11 Cylinder body 12 Oil passage 13 Stacked cylinder head gasket 14 Head bolt A Bolt hole side B Oil hole side h Height t ₁ width t ₂ width W Bead width w ₁ width w ₂ width θ ₁ Rise angle θ ₂ Rise angle

Claims (3)

(57) [Claims] An oil passage communicating from a cylinder body to a cylinder head is provided on a metal cylinder head gasket for an internal combustion engine formed on an outer peripheral side of the engine near a head bolt, by an oil hole for the oil passage and a head bolt for the head bolt. A bolt hole is formed, a bead surrounding these holes is formed by one trapezoidal bead common to both holes, and the cross-sectional shape of the bead in the width direction is set closer to the bolt hole side than the rising angle of the oil hole side. Small rising angle and trapezoidal
Set the top width, which is the width of the flat top of the rod, from the oil hole side.
Oil hole bead with narrow bolt hole side . 2. A metal cylinder head gasket of an internal combustion engine formed on an engine outer peripheral side near a head bolt with an oil passage communicating from a cylinder body to a cylinder head.
The formed an oil hole for the oil passage bolt holes for the head bolts, the beads surrounding the periphery of the holes, are common to both holes formed by a circle arc-shaped beads, the width direction of the bead sectional shape, reducing the rising angle of the bolt hole side than the rise angle of the oil holes side, and bolt hole side oil hole bead to the top of curvature was smaller than the top curvature of the oil hole side. 3. In front of a bead on an oil hole side and a bolt hole side.
Adjust the top shape and the rising angle between the bolt hole side and the oil hole side.
3. The bead for an oil hole according to claim 1, wherein the bead is gradually changed .