Seal for a joint or juncture – Seal between fixed parts or static contact against... – Contact seal between parts of internal combustion engine
Utility Patent
1999-05-24
2001-01-02
Knight, Anthony (Department: 3626)
Seal for a joint or juncture
Seal between fixed parts or static contact against...
Contact seal between parts of internal combustion engine
C277S593000, C277S591000
Utility Patent
active
06168166
ABSTRACT:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a metal gasket with two half beads for sealing a fluid hole situated close to a bolt hole, which is especially suitable for a cylinder head gasket.
In an internal combustion engine, a plurality of cylinder bores is arranged generally linearly, and various holes, such as bolt holes, water holes, oil holes and so on, are arranged around the cylinder bores. Since high temperature and pressure are formed in the cylinder bores, the bolt holes are arranged equally around the cylinder bores to securely and equally seal therearound. However, since the water holes and oil holes do not form extremely high pressure therein, the bolt holes are not arranged equally around these holes, and these holes are simply located near the cylinder bores.
Especially, the oil holes for transferring oil to valves or rotating portions are likely to be formed at the periphery of the engine outside the bolt holes. In this case, when a gasket is installed between a cylinder head and a cylinder block, and is tightened strongly by bolts, the oil holes are not sufficiently compressed, especially at a side opposite to the bolt hole. This is because the cylinder head and/or cylinder block is made of light metal or alloy, such as aluminum alloy, which does not have rigidity. Thus, even if the cylinder head is tightened strongly, the area outside the bolt hole is not compressed sufficiently, so that oil may leak through the oil hole.
In view of the above, U.S. Pat. No. 5,711,537 (Japanese Utility Model Publication (KOKOKU) No. 7-62358) was proposed, wherein a bolt hole and an oil hole are both surrounded by a bead. The spring constant of the bead at the bolt hole side is less than that at the oil hole side, and the middle portions between the bolt hole side and the oil hole side are gradually changed. In this gasket, since the spring constant of the bead is changed according to the unequal tightening force applied thereto, when the bead is compressed, the bead can provide generally equal surface pressure. However, since the spring constant of the bead is changed, it requires a precise processing and the manufacturing cost of the gasket becomes relatively high.
Also, in Japanese Utility Model Publication (KOKOKU) No. 6-45094, a gasket includes a projecting bead surrounding a main hole, and secondary holes, such as bolt hole and oil hole, are disposed in a wide area of the projecting bead to be surrounded by half beads. Since the gasket does not have a bead separating the oil hole from the bolt hole, the oil hole may not be sealed properly. In addition, since the full or half bead surrounding the hole forms a single sealing line, the surface pressure for the bead outside the oil hole becomes weak. Thus, the sufficient sealing can not be made to cause an oil leakage.
In U.S. Pat. No. 5,653,451, an oil bole situated near a bolt hole is surrounded by a sealing bead and a supporting bead. The supporting bead is deviated from the fluid hole to balance the surface pressure around the fluid hole.
Various attempts have been made to solve the problems, but it is still required to improve the sealing ability around the fluid hole near the bolt hole.
In view of the above, the present invention has been made, and an object of the invention is to provide a metal gasket, which can securely seal around a fluid hole near a bolt hole.
Another object of the invention is to provide a metal gasket as stated above, wherein portions to which different tightening pressures are applied when the gasket is tightened are sealed by different beads.
A further object of the invention is to provide a metal gasket as stated above, which can be formed easily and economically.
Further objects and advantages of the invention will be apparent from the following description of the invention.
SUMMARY OF THE INVENTION
A metal gasket of the invention is used for an internal combustion engine having bolt holes and a fluid hole to be sealed. Especially, the gasket is suitable to seal a fluid hole, such as oil hole, located near the bolt hole, to which a sufficient tightening pressure is not applied.
The metal gasket is formed of a main plate for forming the metal gasket, and includes a first hole for constituting one of the bolt holes, a second hole corresponding to the fluid hole and situated adjacent to the first hole, and a full or continuous bead surrounding the first and second holes. The bead includes a first half bead, and a second half bead situated outside the first half bead. The first or inner half bead completely surrounds only the second hole, and the second or outer half bead surrounds the first and second holes. A portion away from the first hole is surrounded by the first and second half beads to securely seal around the second hole, and the first half bead is located between the first and second holes.
In the invention, since the portion around the second hole located away from the first hole has the full bead or first and second half beads, when the gasket is tightened, the full bead can provide sufficient surface pressure thereat. Also, since the first half bead fully surrounds the second hole, the seal around the second hole including the portion between the first and second holes can be made securely. Further, since the second half bead surrounds the first hole together with the second hole, the first hole can be securely sealed. Accordingly, the first and second holes can be secure sealed by the first and second half beads.
In the invention, the gasket may further include a peripheral bead extending around an outer periphery of the gasket. A part of the full bead is located between the peripheral bead and the second hole. Preferably, the peripheral bead is a half bead formed on the main plate. In this case, even if a space between the second hole and the edge of the main plate is narrow, the full bead and the peripheral bead can be formed in the narrow space.
The full bead has the width between the first and second half beads. A first width located at a side away from the first hole is substantially constant, and a second width located at a portion other than the first width is greater than the first width.
REFERENCES:
patent: 4312512 (1982-01-01), Conte et al.
patent: 4372564 (1983-02-01), Nicholson
patent: 4915398 (1990-04-01), Kitagawa
patent: 5022664 (1991-06-01), Kitada et al.
patent: 5078413 (1992-01-01), Miyaoh
patent: 5286039 (1994-02-01), Kawaguchi et al.
patent: 5316322 (1994-05-01), Udagawa et al.
patent: 5582415 (1996-12-01), Yoshida et al.
patent: 5584490 (1996-12-01), Inoue et al.
patent: 5588657 (1996-12-01), Fujisawa et al.
patent: 5626350 (1997-05-01), Kubouchi et al.
patent: 5653451 (1997-08-01), Udagawa
patent: 5711537 (1998-01-01), Inamura et al.
patent: 1 425 524 (1969-03-01), None
Ishikawa Gasket Co. Ltd.
Kanesaka & Takeuchi
Knight Anthony
Patel Vishal
LandOfFree
Metal gasket with two half beads does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Metal gasket with two half beads, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metal gasket with two half beads will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2488318