JPS63210464A - Laminated metal gasket - Google Patents

Abstract

PURPOSE:To compensate the irregularity of a gap between deck faces by providing a compensating section with a preset thickness on the combustion chamber hole side rather than the bead-formed portion in a sealing gasket between deck faces of the cylinder head and cylinder block of an internal combustion engine. CONSTITUTION:A laminated metal gasket 2 has a substrate 4 made of elastic metal plate and the first auxiliary plate 6 and the second auxiliary plate 8 laminated on both sides of it. The substrate 4 has a thickness t1, and the first and second auxiliary plates 6, 8 have thicknesses t2, t3 respectively. A compensating section 22 with a preset thickness is provided at the combustion chamber hole side portion 20 on the combustion chamber hole 10 side rather than the bead portion 18 formed with a bead 12 of this gasket 2 to compensate the irregularity of a gap between deck faces. The thickness T of this compensating section 22 is larger than the gap C generated between deck faces 26a, 28a when a cylinder head 26 and a cylinder block 28 are fastened by a bolt 30. The gap C caused by the distortion of the cylinder head 26 is compensated even if the bolt 30 is fastened further strongly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laminated metal gasket, and in particular, the compensation part of a predetermined thickness provided around the combustion chamber hole can be used to prevent irregularities in the deck surface gap around the combustion chamber that occur when fastening. The present invention relates to a laminated metal gasket that can compensate for this, prevent reduction in sealing effectiveness, achieve stable sealing, and extend service life.

[Conventional technology]

Metal gaskets are used to seal the joint surfaces of members to be joined, for example, the seal between the deck surfaces of a cylinder head and a cylinder block of an internal combustion engine. Metal gaskets are made by elastically deforming the bead formed to seal the sealing surface by the fastening force of a bolt or the like that joins the parts to be joined.
An elastic seal line is formed on the deck surface by the elastic restoring force and amount of elastic restoring during this elastic deformation. This achieves a seal between the deck surfaces and maintains the sealing effect by following the distortion of the deck surfaces.

As such a metal gasket, for example, the applicant of the present invention has already filed an application in Utility Model Application No. 50-60885. The metal gasket disclosed in this invention is a laminated metal gasket in which sub-plates are laminated on both sides of a substrate on which beads are formed, and the elastic restoring force of the bead is sufficiently transmitted to the deck surface by the sub-plates to provide a seal. In addition, the contact surface is appropriately enlarged to achieve uniform surface pressure transmission.

[Problem that the invention seeks to solve]

By the way, when a cylinder head is fastened to a cylinder block using a fastening bolt with a laminated metal gasket interposed therebetween, the cylinder head may be bent due to the fastening force of the bolts, and the gap around the combustion chamber may become large, causing distortion. There is.

As a result, combustion gas leaks from a large gap around the combustion chamber, and the laminated metal gasket is contaminated by this combustion gas, and the sealing effect is reduced due to the accumulation of substances contained therein.

Additionally, when the deck surface gap around the combustion chamber expands and contracts due to combustion pressure during use, an alternating load acts on the bead of the laminated metal gasket, causing it to sag and shortening its service life. There is a risk that the bolts will be affected, damaging the bolts or the cylinder head portion with which the bolts engage, and furthermore, there is a problem in that the bolt fastening force is reduced and the sealing effect is reduced.

[Purpose of the invention]

Therefore, it is an object of the present invention to compensate for irregularities in the deck surface gap around the combustion chamber that occur during fastening by using a compensating part with a predetermined thickness provided around the combustion chamber hole, thereby preventing gasket fouling and reducing the sealing effect, thereby stabilizing the gasket. The object of the present invention is to realize a laminated metal gasket that can achieve a good seal and extend its service life.

[Means for solving problems]

In order to achieve this object, the present invention provides a substrate made of an elastic metal plate surrounding a combustion chamber hole and forming a bead, and auxiliary plates are laminated on both sides of the substrate. A laminated metal gasket is constructed by folding the combustion chamber hole side edge of another sub plate laminated on the other side surface of the substrate to the outside of the combustion chamber hole to form a laminated metal gasket. The present invention is characterized in that a compensation portion having a predetermined thickness is provided in a portion of the metal gasket closer to the combustion chamber hole than the portion where the bead is formed, in order to compensate for irregularities in the deck surface gap.

[Effect]

According to the configuration of the present invention, in order to compensate for irregularities in the deformation surface gap that occur during fastening, a compensating portion having a predetermined thickness is provided in the combustion chamber hole example region than in the region where the bead is formed. This can compensate for irregularities in the deck surface gap around the combustion chamber, prevent the deck surface gap from expanding or contracting due to the influence of combustion gas pressure or engine heat, and weaken the action of alternating loads on the bead. Prevents sagging and provides a stable sealing effect.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings.

1 to 4 show one embodiment of this invention.

In the figure, 2 is a laminated metal gasket, and this laminated metal gasket 2 is composed of a substrate 4 made of an elastic metal plate, and a first sub-plate 6 and a second sub-plate 8 laminated on both sides of the substrate 4. A bead 12 surrounding the combustion chamber hole 10 is formed on the substrate 4 . Further, the substrate 4
A plurality of bolt holes 14 are formed in the first and second sub-plates 6 and 8 around the combustion chamber hole 10, respectively.

The substrate 4 has a thickness tl. The first and second sub-plates 6 and 8 laminated on both sides of the substrate 4 have thicknesses t2 and t3, respectively. The combustion chamber hole side edge 6a of the first sub-plate 6, which is stacked and provided on one side of the substrate 4, is bent in a stepped shape toward the second sub-plate 8 side. The combustion chamber hole side edge 8a of the second sub-plate 8, which is laminated on the other side of the substrate 4, includes the combustion chamber hole side edge 6a of the first sub-plate 6, and extends outside the combustion chamber hole 10. The laminated metal gasket 2 is formed by folding it back toward the side to form a folded portion 16.

A combustion chamber hole side portion 20 which is closer to the combustion chamber hole 10 than the bead portion 8 where the bead 12 of this laminated metal gasket 2 is formed.
In order to compensate for irregularities in the deck surface gap, a compensating part 22 of a predetermined thickness is provided. Compensation member 2
4-1 is fixedly provided, and this compensation member 24-1 and the r-th
The thickness T is determined by the combustion chamber hole side edge 6a of the g+J plate 6, the second sub-plate 8 itself, and the folded combustion chamber hole side edge 8a of the second sub-plate 8, as shown in FIG. The compensation section 22 is provided.

As shown in FIG. 4, the thickness T of this compensating portion 22 is determined by
This gap is larger than the gap C formed between the gaps 8a and 8a. That is,
The thickness t4 of the compensation member 24-1 is t4''T (tl +t2+t3)=(C-(
tl +t 2+j 3) ) xK (however, K=1
．． i~2.0) is set. In this way, the thickness t of the compensation member 24-1
4 is set when the laminated metal gasket 2 is on the deck surface 2.
When compressed between 6a and 28a, the laminated metal gasket 2
Since the overall thickness is reduced, this is to ensure the reduced thickness.

In addition, in FIGS. 3 and 4, the reference numeral 32 is a combustion chamber.

Further, when the substrate 4 and the first sub-plate 6 and the second sub-plate 8 are integrally coupled, for example, a hollow cylindrical stopper (not shown) is inserted into the bolt hole 14 and the stopper is inserted into the bolt hole 14. Both ends are bent onto the surfaces of the first sub-plate 6 and second sub-plate 8 and caulked, or a part of the outer edges of the board 4, first sub-plate 6 and second sub-plate 8 are made to protrude. These protruding parts are spot welded or riveted.

Next, the operation of this embodiment will be explained.

As shown in FIG. 3, the deck surface 26 of the cylinder head 26
The first sub-temporary 6 is brought into contact with a, and the cylinder block 2 is
8, the second sub-plate 8 is brought into contact with the deck surface 28a of the deck surface 28a.
The laminated metal gasket 2 interposed between 6a and 28a is
The bead 12 is compressed by the fastening force of the fastening bolt 30, thereby reducing the height and being compressed and deformed. Due to this deformation, the bead 10 is attached to the first and second deck surfaces 26a and 28a of the cylinder head 26 and cylinder block 28.
A predetermined surface pressure is transmitted by sub-Fi6 and Fi8 to achieve sealing. At this time, the bead 12 gradually reduces its height due to the bolt fastening force, but the compensating portion 22 having the maximum thickness T prevents the bead 12 from being pressed down, that is, the deformation due to the pressure is suppressed.
Does not become flat.

As shown in FIG. 4, when the fastening bolts 30 are tightened even more strongly, distortion occurs in the cylinder head 26 due to insufficient rigidity against the bolt fastening force, and in particular, the deck surface 26a around the combustion chamber 32. There is a problem in that the gap C between 28a is large.

However, as described above, by providing the compensation part 22 with the thickness T in the part 20 closer to the combustion chamber hole than the bead part 18, the thickness T of the compensation part 22 causes a large amount of damage caused by the distortion of the cylinder head 26. It is possible to compensate for the gap C.

Also, at this time, the laminated metal gasket 2 is compressed, and the thickness of the compensating portion 22 is significantly reduced from the thickness T before being tightened.

This makes it possible to prevent combustion gas from leaking from the combustion chamber 32. Also, due to the influence of combustion gas pressure and engine heat, the deck surface 26. The compensator 22 prevents the gap C between a and 28a from expanding or contracting, weakens the alternating load acting on the bead 12, and prevents the bead 10 from becoming sagging. Thereby, the service life of the laminated metal gasket 2 can be extended. Further, it is possible to prevent one-member breakage of the fastening bolt 30 and the cylinder head 26 portion engaged by the fastening bolt 30, and to avoid a reduction in the fastening force of the fastening bolt 30, thereby obtaining a stable sealing effect. .

In this embodiment, the compensating member 24-1 is fixedly provided, but it is also possible to provide the compensating member 24-1 by plating, thermal spraying, painting, etc., or by providing a member made of metal or heat-resistant resin. . Further, in this embodiment, the compensation member 24-1 is provided inside the folded combustion chamber hole side edge 8a of the second sub-plate 8, but as shown by the broken line in FIGS.
A compensation member 24-2 is provided on the outside of the folded combustion chamber hole side edge 8a of the second sub-plate 8 facing the deck surface 26a of the second sub-plate 8.
Compensation members 24-3 and 24- are provided on each side of the combustion chamber hole side edge 6a bent in a step shape of the first sub-plate 6 facing the inside of the sub-plate 8.
4, a compensating member 24-5 is provided inside the second sub-temporary 8 facing the combustion chamber hole side edge 6a of the first sub-plate 6, and a second sub-plate facing the deck surface 28a of the cylinder block 28. Alternatively, the compensation member 24-7 can be provided on the combustion chamber hole side edge 4a of the substrate 4, which is closer to the combustion chamber hole IO than the bead 12. Furthermore, the thickness of the substrate 4 and the first and second sub-plates 6 and 8 can be changed to serve as a compensating member, and the parts other than the laminated metal gasket 2 can be used, for example, the cylinder where the metal gasket 2 is inserted. It is also possible to provide compensation members on the deck surfaces 26a and 28a of the combustion chamber holes rather than on the bead-formed portions of the head 26 and cylinder block 28.

In addition, this compensating member can be provided discontinuously in line segments or dots at desired locations without being continuously provided around the periphery of the combustion chamber hole, and the thickness can also be varied depending on the location. be.

〔Effect of the invention〕

As described above, according to the present invention, in order to compensate for irregularities in the deck surface gap that occur during fastening, a compensating portion with a predetermined thickness is provided at a portion closer to the combustion chamber hole than the portion where the bead is formed, thereby making compensation possible. There is.

Therefore, it is possible to compensate for irregularities in the deck surface gaps of the cylinder head, particularly around the combustion chamber, which occur when the cylinder head is fastened, thereby preventing leakage of combustion gas, etc. from the large gaps around the combustion chamber. Further, it is possible to prevent the metal gasket from being contaminated by leaked combustion gas or the like and from reducing the sealing effect due to the accumulation of contained substances. Furthermore, by weakening the alternating load acting on the bead, it is possible to prevent the bead from becoming sagging, thereby preventing damage to the fastening bolt and the part of the cylinder head that the bolt engages with, thereby extending the service life of the fastening bolt. A decrease in bolt fastening force can be prevented, and a stable sealing effect can be obtained.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, FIG. 1 is a plan view of a laminated metal gasket, and FIG. 2 is ff=II in FIG. 1.
FIG. 3.4 is an enlarged cross-sectional view taken along the line, and is a cross-sectional view of a state in which a laminated metal gasket is interposed between joining members and tightened. FIGS. 5 and 6 are cross-sectional views of laminated metal gaskets illustrating other embodiments of the present invention. In the figure, 2 is a laminated metal gasket, 4 is a substrate, 4a
is the combustion chamber hole side edge, 6 is the first sub-plate, 6a is the combustion chamber hole side edge, 8 is the second sub-plate, 8a is the combustion chamber hole side edge, 10 is the combustion chamber hole, 12 is the bead, 16 is a folded portion, 18 is a bead portion, 2o is a combustion chamber hole side portion, 22 is a compensation portion, 24 is a compensation member, 26 is a cylinder head, 26a is a deck surface, 2
8 is a cylinder block, 28a is a deck surface, and 32 is a combustion chamber.

Claims (1)

[Claims] Sub-plates are laminated on both sides of a substrate made of an elastic metal plate forming a bead surrounding a combustion chamber hole, and the edge of one of the sub-plates laminated on one side of the substrate is included. A laminated metal gasket is constructed by folding the combustion chamber hole side edge of another sub-plate laminated on the other side of the substrate to the outside of the combustion chamber hole, and A laminated metal gasket characterized in that a compensating part of a predetermined thickness is provided in a part on the combustion chamber hole side to compensate for irregularities in the deck surface gap.