JPH1061771A - Metal gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a load, in a metal gasket insertion interposed in a mating face between a cylinder head and a cylinder block, so as to prevent generation of sinking of a cylinder sleeve, deformation of the cylinder head in the periphery of a combustion chamber and deformation of the cylinder head or the like having a subcombustion chamber, also fill a clearance of the mating face generated in the case of tightening the cylinder head and the cylinder block by a bolt. SOLUTION: In a metal gasket insertion interposed in a mating face of a cylinder head 15 and a cylinder block 13 of an internal combustion engine to be tightened by a bolt 19, a subplate 4, having a sheet or more of hard substrate and width around a combustion chamber hole 5 of any hard base plate 3 leading to the internal periphery of a cooling water passage 16 of the cylinder block 13 from a peripheral edge of the combustion chamber hole 5, is superposed to be bonded, also in the superposition part of the base plate 3 and the subplate 4, a bead 3a enveloping a combustion chamber 14 is formed. In this way, load distribution of the subplate 4, when the bolt 19 is tightened, is maximized in the periphery of the subplate 4, leading to its internal periphery, to be gradually decreased, so as to fill a clearance of the mating face, enlarged in accordance with separating distant from a tightening of the bolt 19, by the bead 3a of the base plate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal gasket to be inserted into a mating surface between a cylinder head and a cylinder block of an internal combustion engine.

[0002]

2. Description of the Related Art FIG. 15 shows a cross-sectional view in which a conventional metal gasket is inserted into a mating surface of a cylinder head and a cylinder block of an internal combustion engine.

[0003] As shown in FIG.
A cylinder sleeve 31 is provided on the inner periphery of the cylinder 0. The metal gasket 33 fits the grommet 36 around the combustion chamber hole 35 of the sub-plate 34, and overlaps the elastic substrates 38, 38 on the upper and lower surfaces of the sub-plate 34 on the outer periphery of the grommet 36,
Half beads 39 are formed on the combustion chamber 41 side and the outer peripheral side of each elastic substrate 38.

In such a metal gasket 33, the thickness of the grommet 36 is formed to be larger than the thickness of the elastic substrates 38, 38 so as to act as a stopper forming a primary seal between the cylinder head 40 and the cylinder block 30. The outer peripheral half bead 39 forms a secondary seal.

Therefore, according to such a metal gasket 33, since the load distribution acting around the combustion chamber 41 is concentrated on the grommet 36, an extra load is applied to the upper surface of the cylinder sleeve 31, and this cylinder sleeve 31 There was a problem that 31 was depressed downward.

Another problem is that the vicinity of the combustion chamber of the aluminum cylinder head 40 is deformed so as to be softened and depressed by the influence of heat from the combustion chamber 41.

FIGS. 16 and 17 are cross-sectional views showing a conventional metal gasket 46 inserted into a mating surface of a cylinder head 44 and a cylinder block 45 of an engine having a sub-combustion chamber 43 conventionally used for a diesel engine. FIG.

The structure is such that a hot plug 47 is embedded in a lower portion of a cylinder head 44 and a sub-combustion chamber 43 formed in the hot plug 47 communicates with a main combustion chamber 49 of a cylinder block 45 through a passage 48. That is, the rich mixed gas sent to the sub-combustion chamber 43 is ignited, and the thin mixed gas in the main combustion chamber 49 is stably burned using this as a fire. Accordingly, the sub-combustion chamber 43 is provided below the cylinder head 44 near the main combustion chamber 49.

The conventional metal gasket 46 applied to such an engine with a sub-combustion chamber is formed by superimposing two layers of a first substrate 50 and a second substrate 51, and a combustion chamber hole formed in the first substrate 50 is formed. By mounting the grommet 53 on the periphery of the grommet 52 and increasing the load on the grommet 53 (indicated by the black arrow in FIG. 16), a gap between the cylinder head 44 and the cylinder block 45 generated when the cylinder block 45 is tightened with the bolt 54 is formed. Is sealed with a grommet 53.

However, when the bolt 54 is fastened in a state where the grommet 53 is located on the lower surface of the hot plug 47, the load of the grommet 53 is pressed against the lower surface of the hot plug 47, and the hot plug 47 is pushed by an arrow in FIG. As shown in FIG. 9, the inclination of the hot plug 47 is enlarged and the peripheral surface of the cylinder head 44 is deformed by the effect of the explosion pressure and combustion heat from the main combustion chamber 49. There was a problem.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a metal gasket inserted into a mating surface of a cylinder head and a cylinder block is capable of causing a cylinder sleeve to collapse and burn. The load is adjusted so that deformation of the cylinder head around the chamber and deformation of the cylinder head having the sub-combustion chamber do not occur, and a gap generated when the cylinder head and the cylinder block are tightened with bolts (go away from the bolt fastening position) It is an object of the present invention to provide a metal gasket that fills a gap between mating surfaces that expands according to the following formula.

[0012]

In order to solve the above-mentioned problems, a metal gasket according to the present invention is a metal gasket which is bolted by being inserted into a mating surface of a cylinder head and a cylinder block of an internal combustion engine. One or more sub-plates having a width extending from the periphery of the combustion chamber hole to the inner periphery of the cooling water passage of the cylinder block around the combustion chamber hole of any of the hard substrates are superposed and bonded together. By forming a bead surrounding the combustion chamber hole at the overlapping portion of the substrate and the sub-plate, the load distribution of the sub-plate at the time of tightening the bolt is maximized at the outer periphery of the sub-plate, The gap between the mating surfaces, which gradually becomes smaller toward the inner circumference and expands further away from the bolted portion, is filled with beads of the substrate.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is an exploded perspective view of a metal gasket according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the metal gasket after the connection corresponding to the position of line AA in FIG. FIG. 3 is a cross-sectional view showing a load distribution state in which the metal gasket of FIG. 2 is inserted into a mating surface of a cylinder head and a cylinder block. 4 to 11 are views showing another embodiment of the metal gasket related to the first embodiment.

In this embodiment, a cylinder block 13 in which a cylinder sleeve 12 (see FIG. 3) is provided on the inner periphery of each open-deck type combustion chamber 5 in which a plurality of combustion chambers 5 are continuously formed is provided. 2 shows an example in which a metal gasket according to the present invention is interposed in a mating surface of the present invention.

In FIG. 1, this metal gasket has an upper substrate 2 and a lower substrate 3 formed of a hard metal plate, and a sub-plate 4 is arranged between the upper substrate 2 and the lower substrate 3. The sub-plate 4 is bonded to the lower substrate 3 as described later.

The upper substrate 2 and the lower substrate 3 are provided with a cylinder block 13 and a cylinder head 15 in accordance with the state of formation.
A combustion chamber hole 5, an oil hole 6, a cooling water hole 7, a bolt hole 8 and the like are formed, and these substrates 2, 3 are fixed with rivets 9 around their outer periphery and joined as shown in FIG.

In FIG. 2, the auxiliary plate 4 extends from the periphery of the combustion chamber hole 5 of the lower substrate 3 to the cooling water passage 1 of the cylinder block 13.
6, the beads 3a, 4a surrounding the combustion chamber hole 5 are superimposed and adhered to the upper surface of the lower substrate 3 in the area where the lower substrate 3 and the sub-plate 4 overlap. At the same time, a bead 2a is formed at the same position on the upper substrate 2.

The shapes of the beads 2a, 3a are asymmetrical arcs having straight portions 2c, 3c on the combustion chamber hole 5 side, and the formation portions of the beads 2a, 3a do not act on the upper surface of the cylinder sleeve 12. Like each bead 2a,
The inner periphery of 3a is a flat portion 11.

As shown in FIG. 2, a plurality of cooling water holes 7 (see FIG. 1) are formed near the outer periphery of the combustion chamber hole 5,
A step-shaped bead 2b is formed along the vicinity of the outer periphery of the upper substrate 2.

Further, a rubber coating 1 is provided on both surfaces of the upper substrate 2.
8 and a rubber coating 1 on the lower substrate 3 only on the lower surface.
8 is given.

With such a configuration, as shown in FIG. 3, bolts 19 for connecting the cylinder head 15 and the cylinder block 13 are provided near their outer circumferences (positions indicated by dashed lines extending from the bolts 19 in FIG. 3). In this case, even if the sub-plate 4 has an even thickness, the tightening force of the bolt 19 increases as the position near the bolt 19 increases. The side has a maximum load F1 and then gradually decreases as it moves away from it and has a minimum load F2 at the periphery of the combustion chamber hole 5.

Further, by fastening the bolt 19,
The gap between the mating surface of the cylinder head 15 and the cylinder block 13 increases as the distance from the fastening position of the bolt 19 increases, and has a maximum gap near the combustion chamber 14.

In the present invention, this gap is
And the loads f1, f of the beads 2a, 3a provided on the lower substrate 3.
2 to replenish the gas and blow off the combustion gas from the combustion chamber 14.

The bead 2b provided in the vicinity of the outer periphery of the upper substrate 2 has a load f3.
And the gap between the mating surfaces near the outer periphery of the cylinder block 13 can be sealed.

Further, between adjacent bolts 19, 19 (FIG. 1)
(Corresponding to any of the bolt holes 8 provided adjacent to the bolts 8), the gap between the mating surfaces of the cylinder head 15 and the cylinder block 13 increases as the distance from each bolt 19 increases. , 3a can be adjusted.

In the present invention, since the auxiliary plate 4 is provided in a range from the peripheral edge of the combustion chamber hole 5 of the lower substrate 3 to the inner periphery of the cooling water passage 16, as shown in FIG. The load of the sub-plate 4 also acts on the upper surface of the sleeve 12. Incidentally, when the inner periphery of the sub-plate 4 is formed on the outer periphery of the cylinder sleeve 12, the load of the sub-plate 4 is concentrated on the upper surface of the cylinder block 13, so that the upper surface of the cylinder block 13 may be partially depressed.

However, as described above, the load of the sub-plate 4 on the side of the minimum load F2 also acts on the upper surface of the cylinder sleeve 12 in a distributed manner, thereby simultaneously preventing the cylinder block 13 and the cylinder sleeve 12 from being depressed. It has become possible.

The maximum load F1 of the auxiliary plate 4 is
Therefore, deformation of the cylinder head 15 near the combustion chamber, which is directly affected by the heat effect of the combustion chamber 14, can be avoided.

As a method of manufacturing the substrate 3 having such a sub-plate 4, the sub-plate 4 which is softer than the substrate 3 is bonded to the substrate 3 before bead forming, and then the beads 3a, 4a are collectively formed. Or, while forming the bead 3a on the substrate 3,
The beads 4a may be formed on the hard sub-plate 4 and then bonded together.

According to such a configuration, since the shape of the bead 4a of the sub-plate 4 matches the shape of the bead 3a of the substrate 3, there is also an advantage that the displacement of the sub-plate 4 is prevented.

The hardness of the metal plate used as the sub-plate 4 depends on what magnitude of elastic force is applied to the bead 4a of the sub-plate 4. That is, when the bead load is insufficient with only the beads 2a and 3a of the substrates 2 and 3, the hardness of the metal plate used for the sub-plate 4 is selected to reduce the insufficient bead load with the bead 4a of the sub-plate 4. It is better to make up for it.

Hereinafter, a modification of the metal gasket of the first embodiment will be described.

The metal gasket shown in FIG. 4 is obtained by turning the metal gasket of FIG. 2 upside down.
And beads 2a, 3a and 4a are formed around the overlapping portion of the upper substrate 2 and around the combustion chamber hole 5 of the lower substrate 3.

The shapes of these beads are similar to those of the metal gasket of FIG.
As an asymmetric arc-shaped bead with c. The metal gasket shown in FIG. 5 is obtained by changing the bead shape of the metal gasket of FIG. 2 and is an asymmetric arc-shaped bead having straight portions 2c and 3c on the cooling water hole 7 side.

The bead shapes in FIG. 4 (or FIG. 2) and FIG. 5 are both asymmetric, but in FIG. 4, the bead height is large near the cooling water hole 7. Thus, the maximum load F1 of the sub-plate 4 can be further increased. Further, in FIG. 5, since the bead height is large near the combustion chamber hole 5, the clearance between the mating surface of the cylinder head 15 and the cylinder block 13 which is further enlarged on the combustion chamber 14 side when the bolt 19 is fastened. Can be effectively filled.

Further, the metal gasket shown in FIG. 6 is a bilaterally symmetric arc-shaped bead, and has an intermediate effect between the bead shapes shown in FIGS.

The metal gasket shown in FIG. 7 has a spacer plate 17 interposed between the upper substrate 2 and the lower substrate 3 of the metal gasket of FIG. Step beads 2b, 3b are formed on the spacer plate 17 and the thickness of the entire metal gasket can be changed by adjusting the thickness of the spacer plate 17.

In this metal gasket, the sub-plate 4 is provided inside the upper substrate 2, but the sub-plate 4 may be provided inside the lower substrate 3.

As shown in FIG. 8, the sub-plate 4 may be provided on both the upper substrate 2 and the lower substrate 3.

Further, in the metal gasket shown in FIGS. 9 to 11, the sub-plate 4 is bonded to one hard substrate 2 'in the same range as described above so that the thickness of the entire metal gasket is reduced. It was done.

In the metal gasket shown in FIG. 9, a sub-plate 4 is adhered to the lower surface of a substrate 2 ', and beads 2'a, 4a surrounding a combustion chamber hole 5 are formed at the overlapping portion of the substrate 2' and the sub-plate 4. And a sub-plate 4 'is adhered along the outer periphery of the substrate 2', and stepped beads 2'b, 4'b are also formed at the outer periphery.

In the metal gasket of FIG. 9, the effect of the sub-plate 4 as shown in FIG. 2 is obtained by making the thickness of the sub-plate 4 on the combustion chamber hole 5 side larger than the thickness of the sub-plate 4 'on the outer peripheral side. That is, the maximum load of the sub-plate when the cylinder head and the cylinder block are bolted together can be applied to the inner peripheral side of the cooling water passage, and the gap of the mating surface extending farther from the bolted position is formed in the bead 2a '. Can be filled by

In the metal gasket of FIG. 10, the shape of the substrate 2 'is the same as that of FIG. On the top side of

Further, the metal gasket of FIG. 11 does not have the auxiliary plate 4 'on the outer peripheral side of the metal gasket of FIG.

The beads of the metal gasket in FIGS. 7 to 11 are all asymmetrical arcs having a straight portion on the side of the combustion chamber hole 5, but as shown in FIGS. The shape may be an asymmetrical or symmetrical arc having a straight portion on the 7 side.

In the metal gasket shown in FIGS. 9 to 11, the rubber coating 18 is provided on the sub-plate 4 or 4 'of the substrate 2'.
The sub-plate 4 is provided on the outer surface of the sub-plate 4, and the substrate 2 ′ on the same side as the sub-plate 4 is provided up to the inner periphery of the cooling water passage 16.

In the metal gaskets shown in FIGS. 9 and 11, the rubber coating 1 on the cooling water passage 16 side of the substrate 2 'is used.
Since the cooling water 8 is not exposed to the cooling water passage 16, the rubber does not peel off due to the cooling water.

Embodiment 2 FIG. 12 is a plan view of a metal gasket according to Embodiment 2 of the present invention. FIG. 13 shows FIG.
FIG. 3 is an enlarged view of a circular portion indicated by a two-dot chain line C. FIG. 14 is a partial sectional view in which the metal gasket of the second embodiment corresponding to the position of the line BB in FIG. 12 is applied to an engine with a sub-combustion chamber.

In this embodiment, as shown in FIG. 14, a metal gasket according to the present invention is applied to a mating surface of a cylinder head 21 and a cylinder block 22 having a sub-combustion chamber 20 used for a diesel engine or the like. It is.

In the metal gasket of this embodiment, similarly to the metal gasket of FIG. 2, two elastic substrates 2 and 3 are joined by rivets 9 and a sub-plate 4 is adhered to the inner surface of the lower substrate 3. The overlapping area of the sub-plate 4 extends from the periphery of the combustion chamber hole 5 to the cooling water passage 1.
6 up to the inner circumference.

The bead around the combustion chamber hole 5 is provided with double step beads 2d, 2e, 3d and 3e, and a flat surface 11 'is provided between both beads. Also at 14, the beads 2 e, 3 e provided on the side of the cooling water hole 7 of the sub-plate 4 exhibiting the maximum load when the metal gasket is fastened near the outer periphery of the metal gasket as in FIG. 23 is formed at a position avoiding the hot plug 23 to prevent deformation of the hot plug 23 and to fill the gap with the beads 2d and 3d on the combustion chamber 24 side having the maximum gap width when the bolt 19 is fastened.

Various modifications of the metal gasket of the second embodiment, such as the one provided with a spacer as in the first embodiment and the one using a single elastic substrate, are also conceivable.

[0054]

As described above, according to the metal gasket of the present invention, the sub-plate is adhered in the range from the periphery of the combustion chamber hole of the hard substrate to the inner periphery of the cooling water passage, and the combustion chamber of the substrate is formed. Since a bead is formed around the hole, when the metal gasket is inserted into the mating surface of the cylinder head and cylinder block and bolted, the maximum load of the sub-plate acts on the inner peripheral side of the cooling water passage, and at the same time the bolt is tightened The gap between the mating surfaces extending farther from the position can be filled with a bead around the combustion chamber hole.

Therefore, in the case of the engine having the cylinder sleeve, the state in which the maximum load of the sub-plate does not act on the upper surface of the cylinder sleeve as in the prior art, that is, the depression of the cylinder sleeve or the deformation of the cylinder head near the combustion chamber is avoided. In this state, it is possible to seal the maximum gap between the cylinder head and the cylinder block around the combustion chamber with a bead.

In the case of a diesel engine or the like having a sub-combustion chamber, a state in which the maximum load of the sub-plate does not act on the lower surface of the hot plug in the sub-combustion chamber, that is, a state in which deformation of the hot plug and the cylinder head around it is avoided. Thus, it is possible to seal the maximum gap between the cylinder head and the cylinder block around the combustion chamber with a bead.

Further, in the present invention, since the bead of the substrate and the bead of the sub-plate adhered to the substrate are in a superposed state, it is possible to prevent the deviation of the sub-plate from the substrate.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a metal gasket according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the completed metal gasket corresponding to the position along the line AA in FIG.

FIG. 3 is a cross-sectional view showing a load state in which the metal gasket of the embodiment is inserted into a mating surface of a cylinder head and a cylinder block.

FIG. 4 is a sectional view showing a modification of the first embodiment.

FIG. 5 is a sectional view showing a modification of the first embodiment.

FIG. 6 is a sectional view showing a modification of the first embodiment.

FIG. 7 is a sectional view showing a modification of the first embodiment.

FIG. 8 is a sectional view showing a modification of the first embodiment.

FIG. 9 is a sectional view showing a modification of the first embodiment.

FIG. 10 is a sectional view showing a modification of the first embodiment.

FIG. 11 is a cross-sectional view showing a modification of the first embodiment.

FIG. 12 is a plan view of a metal gasket according to Embodiment 2 of the present invention.

FIG. 13 is an enlarged view of a circular portion indicated by a two-dot chain line C in FIG.

14 is a partial cross-sectional view in which the metal gasket according to the second embodiment corresponding to the position of line BB in FIG. 12 is applied to an engine with a sub-combustion chamber.

FIG. 15 is a cross-sectional view showing a state where a conventional metal gasket is applied to an engine having a cylinder sleeve.

FIG. 16 is a cross-sectional view showing a state in which a conventional metal gasket is applied to an engine with a sub-combustion chamber.

FIG. 17 is a partial cross-sectional view showing a state in which the grommet of the conventional metal gasket pushes a constituent member of the sub-combustion chamber toward the cylinder head side under the state of FIG.

[Description of sign]

 2, 3 ... substrate, 2a, 3a ... substrate bead 2b ... stepped bead 4 ... sub plate 4a ... sub plate bead 5 ... combustion chamber hole 6 ... oil hole 7 ... cooling water hole 8 ... bolt hole 9 ... rivet 11, 11 '... flat surface 12 ... cylinder sleeve 13 ... cylinder block 14 ... combustion chamber 15 ... cylinder head 16 ... cooling water passage 18 ... rubber coating 19 ... bolt 21 ... cylinder head 20 ... auxiliary combustion chamber 22 ... cylinder block 23 ... Hot plug 24: Combustion chamber

Claims (1)

[Claims] 1. A metal gasket which is bolted by being inserted into a mating surface of a cylinder head and a cylinder block of an internal combustion engine, comprising one or more hard substrates,
Around a combustion chamber hole of one of the hard substrates, a sub-plate having a width extending from the peripheral edge of the combustion chamber hole to the inner periphery of the cooling water passage of the cylinder block is superposed and bonded, and the substrate and the sub-plate are bonded together. By forming a bead surrounding the combustion chamber hole at the overlapped portion, the load distribution of the sub-plate at the time of tightening the bolt is maximized at the outer periphery of the sub-plate, and gradually becomes smaller toward the inner periphery thereof, The metal gasket is characterized in that a gap between the mating surfaces, which expands as the bolt gets farther from a fastening portion, is filled with a bead of the substrate.