JP2008111540A - Cylinder head gasket - Google Patents

Abstract

A cylinder head gasket capable of exhibiting sufficient sealing performance around a cylinder bore hole and suppressing deformation of an engine cylinder bore.
Around a cylinder bore hole, a first metal component plate is formed with a folded portion, and a second metal component plate laminated on the first metal component plate is attached to the first metal component. A cylinder head gasket 1 in which a full bead 21 having a convex on the component plate 10 side is formed facing each other, and a convex portion 21a of the full bead 21 is arranged on an inner peripheral side of an end portion 11a of the folded portion 11, At least one or more sub-plates 30 and 40 are inserted and arranged inside the portion 11. Furthermore, the plate thickness t2 around the cylinder bore hole 2 of the second metal constituting plate 20 is formed to be smaller than half th of the thickness tg of the folded portion 11.
[Selection] Figure 1

Description

  The present invention relates to a cylinder head gasket that is sandwiched between two members such as an engine cylinder head and a cylinder block for sealing, and more specifically, is rubbed due to external factors such as thermal deformation of members on both sides. The present invention relates to a cylinder head gasket that can suppress an increase in surface pressure at a bore tip portion and reduce indentation or the like generated in a member even when the displacement occurs.

  The cylinder head gasket is sandwiched between the cylinder head of an automobile engine and a cylinder block (cylinder body) and is fastened by a head bolt to seal fluid such as combustion gas, oil, and cooling water. Yes.

  In addition, the recent reduction in weight and size of the engine has led to a reduction in the rigidity of the engine. When a large seal surface pressure is applied to the cylinder bore gasket in order to ensure sealing performance, the engine member has a low rigidity. Therefore, there is a problem that the cylinder bore is deformed. When the cylinder bore is deformed, the sealing means such as the bead and the folded portion do not sufficiently function, and an appropriate sealing performance cannot be obtained.

  On the other hand, the number of laminated layers is small, the amount of steel used is reduced, the thickness of the entire gasket is reduced, and at the cylinder edge, the tightening pressure at the cylinder edge is maximized to provide sufficient sealing performance. The sub-plate is folded back directly to form a wide folded portion (grommet portion), and the two main plates sandwiching the sub-plate are provided with full beads with the convex side of the sub-plate, and this full bead collides with the folded portion. Metal gaskets that have been made have been proposed (see, for example, Patent Document 1 and Patent Document 2).

However, in this cylinder head gasket, the cylinder mouth edge portion has the highest tightening pressure (seal pressure), and thus the problem that the cylinder bore deformation is promoted cannot be solved. Further, since the folded portion is directly folded and the folded diameter of the folded portion is small, there is a problem that cracks are likely to occur.
JP-A-8-121597 JP-A-10-213227

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sufficient sealing performance around the cylinder bore hole and to provide an indentation around the cylinder bore hole generated in the engine member. To provide a cylinder head gasket that can reduce the above.

  In order to achieve the above object, a cylinder head gasket according to the present invention includes a second metal formed by forming a first metal component plate with a folded portion around a cylinder bore hole and laminating the first metal component plate. A full bead having a convex on the first metal component plate side is formed on the component plate, the convex portion of the full bead is disposed on the inner peripheral side of the end portion of the folded portion, and at least inside the folded portion One or more sub-plates are inserted and arranged.

  According to this configuration, the thickness of the folded portion can be increased by inserting and arranging the sub-plate inside the folded portion, so that the curvature of the folded portion is increased and the occurrence of cracks can be prevented.

  In the cylinder head gasket, the second metal component plate is laminated on the folded portion side of the first metal component plate. In this configuration, the stacking position of the second metal component plate is changed from the side without the folded portion to the side with the folded portion, but the same effect as described above can be obtained.

  In the above cylinder head gasket, the thickness of the second metal component plate around the cylinder bore hole is formed to be smaller than half the thickness of the folded portion. With this configuration, even when a large tightening force is generated around the cylinder bore hole, at the peripheral edge of the cylinder bore hole, the end of the second metal component plate enters the rounded portion side of the folded portion, and the peripheral edge of the cylinder bore As a result, excessive sealing pressure is not applied to the cylinder bore, so that deformation of the cylinder bore can be suppressed.

  In the above cylinder head gasket, a ring-shaped first sub-plate that is flat on the inner peripheral side of the end portion of the folded portion, and a bead on the inner peripheral side of the end portion of the folded portion, inside the folded portion. When the second sub plate is inserted and arranged, the thickness of the folded portion can be adjusted by the first sub plate and the second sub plate, and the compressibility of the folded portion can be increased by the bead of the second sub plate. In addition, it is possible to prevent the folded portion from sag.

  Moreover, if the convex part of a 2nd metal component board and the convex part (contact part with a 1st metal component board) of a bead of a 2nd subplate are made into the same position by planar view, a bigger sealing pressure will be generated. In addition, when the two are shifted from each other in plan view, a relatively large seal pressure region can be provided widely while reducing the maximum seal pressure.

  According to the cylinder head gasket of the present invention, sufficient sealing performance can be exhibited around the cylinder bore hole, and deformation of the cylinder bore of the engine can be suppressed by suppressing the seal pressure at the peripheral edge of each cylinder bore hole to a small value.

  In particular, even when the upper surface side and the lower surface side of the cylinder head gasket rub against each other due to external factors such as thermal deformation of the cylinder head or cylinder block, the surface pressure at the bore tip increases. Can be suppressed, and indentations and the like generated in the cylinder head and the cylinder block can be reduced.

  Next, an embodiment of a cylinder head gasket according to the present invention will be described with reference to the drawings. 1 to 4 are schematic explanatory diagrams, and in order to make the configuration easier to understand, dimensions such as the plate thickness, the size of the hole for the cylinder bore, the size of the folded portion, and the size of the bead are shown. It is exaggerated, different from the actual one.

  A cylinder head gasket according to the present invention is a metal gasket sandwiched between an engine member of an engine cylinder head and a cylinder block (cylinder body), and includes a high-temperature and high-pressure combustion gas in a cylinder bore, a cooling water passage, Seals fluid such as cooling water and oil in the cooling oil passage.

  This cylinder head gasket has a single or a plurality of metal component plates (metal substrates) formed of a mild steel plate, a stainless annealed material (annealed material), a stainless tempered material (spring steel plate), or the like. In addition, it is manufactured according to the shape of the engine member such as the cylinder block, and has a cylinder bore hole (combustion chamber hole), a liquid hole for circulating coolant and engine oil, a bolt hole for fastening head bolts, etc. The

  First, a first embodiment of the present invention will be described. As shown in FIGS. 1 and 2, the cylinder head gasket 1 according to the first embodiment includes two metal constituent plates 10 and 20 and three sub-plates 30, 40 and 50. The first metal component plate 10 is formed of a stainless annealed material, and the second metal component plate 20 is formed of a stainless spring steel plate. Moreover, the 1st subplate 30 is formed with a mild steel plate or a stainless steel annealing material, and the 2nd subplate 40 which has the full bead 41 is formed with a stainless steel refining material. Furthermore, the 3rd subplate 50 which has the half bead 51 is formed with a stainless steel annealing material.

  The first metal component plate 10 is formed to have a folded portion 11 by folding around the cylinder bore hole 2. The second metal component plate 20 is formed by laminating the first metal component plate 10 on the side where the folded portion 11 is not provided. The second metal component plate 20 has the first metal component plate 10 side (inner side) convex. The full bead 21 is provided, and the convex portion 21 a of the full bead 21 is arranged on the inner peripheral side of the end portion 11 a of the folded portion 11.

  Further, the first sub-plate 30 and the second sub-plate 40 are inserted and arranged inside the folded portion 11. The first sub-plate 30 is formed flat on the inner peripheral side of the end portion 11a of the folded portion 11. The second sub-plate 40 is formed as a ring-shaped plate having a full bead 41 on the inner peripheral side of the end portion 11 a of the folded portion 11. In plan view, the end 40a on the inner peripheral side of the second sub-plate 40 is located at the same position as the end 30a on the inner peripheral side of the first sub-plate 30, and the end 40b on the outer peripheral side of the second sub-plate 40. Is the same position as the end portion 11 a of the folded portion 11. By inserting and arranging the sub-plates 30 and 40, the thickness tg of the folded portion 11 can be increased, so that the curvature of the rounded portion 11b of the folded portion 11 is increased and the occurrence of cracks can be prevented. Furthermore, the full bead 41 of the second sub-plate 40 can increase the compressibility of the folded portion 11 and prevent the folded portion 11 from sag. A full bead 41 is normally used as the full bead 41 of the second sub-plate 40, but a half bead may be used as long as it can prevent the folded portion 11 from sag. Also, a combination of several beads may be used.

  Further, as shown in FIG. 2, the plate thickness t2 around the cylinder bore hole 2 of the second metal component plate 20 is made smaller than half th of the thickness tg of the folded portion 11. That is, t2 <th (= tg / 2). In addition, since the thickness tg of the folding | returning part 11 becomes thick by insertion arrangement | positioning of the subplates 30 and 40 inside the folding | returning part 11, plate | board thickness t2 around the cylinder bore hole 2 of the 2nd metal component board 20 is easy. Can be made smaller than half th of the thickness tg of the folded portion 11.

  In the periphery of the water hole 3, the second metal component plate 20 is configured to have a half bead 22 and a half bead 23. The convex direction of the half bead 23 is formed in the same direction as the convex portion 41 a of the full bead 41 of the second sub-plate 40. The third sub-plate 50 is formed with a half bead 51 having a direction opposite to that of the half bead 23. The two half beads 23 and 51 are arranged at the same position in plan view. That is, it arrange | positions so that each inclination part of each half bead 23 and 51 may overlap in planar view. Further, the end portion 50 a on the peripheral side of the cylinder bore hole 2 of the third sub-plate 50 is formed to be closer to the outer peripheral side than the end portion 11 a of the folded portion 11.

  Accordingly, in the peripheral portion of the cylinder bore hole 2, the rounded portion 11 b of the folded portion 11 of the first metal component plate 10 and the end portion 20 a of the second metal component plate 20 are aligned, and in the peripheral portion of the water hole 3. The end portions 10b and 20b of the first and second metal constituting plates 10 and 20 are aligned with the end portions 30b and 50b of the first sub plate 30 and the third sub plate 50, respectively.

  According to the cylinder head gasket 1 configured as described above, even when a large tightening force is generated around the cylinder bore hole 2 due to the thickness, the second metal component plate 20 is formed at the peripheral portion of the cylinder bore hole 2. Since the end portion 20a enters the rounded portion 11b side of the folded portion 11, no large surface pressure is generated at the peripheral portion of the cylinder bore hole 2, and the maximum surface pressure is generated on the outer peripheral side. As a result, excessive sealing pressure is not applied to the peripheral edge of the cylinder bore of the engine, so that deformation of the cylinder bore can be suppressed. That is, by suppressing the maximum value of the surface pressure at the peripheral edge of each cylinder bore hole 2, deformation of each cylinder bore is prevented. Note that the width of the folded portion 11 and the shapes and sizes of the beads 21 and 41 can be obtained from a surface pressure distribution obtained from experiments and calculations.

  Further, when a large tightening force is not applied, an appropriate sealing pressure is also applied to the peripheral portion of the cylinder bore by the folded portion 11 and the full bead 21, and further, a sealing pressure is applied by a seal line formed by the full bead 21 on the outer peripheral side. Therefore, excellent sealing performance can be exhibited.

  Further, the thickness tg of the folded portion 10 can be adjusted by the first sub plate 30 and the second sub plate 40, and the compressibility of the folded portion 11 can be increased by the full bead 41 of the second sub plate 40, and the folded portion 11 can be increased. Prevents drooling. A full bead 41 is normally used as the full bead 41 of the second sub-plate 40, but a half bead may be used as long as it can prevent the folded portion 11 from sag. Also, a combination of several beads may be used.

  Moreover, if the convex part 21a of the full bead 21 of the 2nd metal structural plate 20 and the convex part (contact part with a 1st metal structural plate) 41a of the full bead 41 of the 2nd subplate 40 are made into the same position by planar view. A larger seal pressure can be generated, and if these two positions are shifted from each other in plan view, a region of a relatively large seal pressure can be widened while reducing the maximum seal pressure.

  With these configurations, even when the upper surface side and the lower surface side of the cylinder head gasket 1 are rubbed and displaced due to external factors such as thermal deformation of the cylinder head or the cylinder block, the tip of the bore An increase in surface pressure at the portion can be suppressed, and indentations and the like generated in the cylinder head and the cylinder block can be reduced.

  In the above description, the full beads 21 and 41 are described as beads having a circular cross-sectional shape. However, the bead shape is not particularly limited in the present invention, and the cross-sectional shape is an arc shape, a sine shape (cosine), or a trapezoidal shape. , A triangular (mountain) shape, or the like.

  Next, a second embodiment of the present invention will be described. As shown in FIGS. 3 and 4, the cylinder head gasket 1 </ b> A according to the second embodiment includes two metal component plates 10 and 20 </ b> A and three sub-plates 30, 40 and 50. The first metal component plate 10 is formed of a stainless annealed material, and the second metal component plate 20A is formed of a stainless spring steel plate. Moreover, the 1st subplate 30 is formed with a mild steel plate or a stainless steel annealing material, and the 2nd subplate 40 which has the full bead 41 is formed with a stainless steel refining material. Furthermore, the 3rd subplate 50 which has the half bead 51 is formed with a stainless steel annealing material.

  The first metal component plate 10 is formed to have a folded portion 11 by folding around the cylinder bore hole 2. The second metal component plate 20A is configured by being laminated on the folded portion 11 on the side where the folded portion 11 of the first metal component plate 10 is present, and the second metal component plate 20A includes the first metal component plate 10 side. A full bead 21 </ b> A having a convex (inner side) is provided, and the convex portion 21 </ b> Aa of the full bead 21 </ b> A is disposed on the inner peripheral side of the end portion 11 a of the folded portion 11.

  In addition, the first sub-plate 30 and the second sub-plate 40 are inserted and arranged inside the folded portion 11. The first sub-plate 30 is formed flat on the inner peripheral side of the end portion 11a of the folded portion 11. The second sub-plate 40 is formed as a ring-shaped plate having a full bead 41 on the inner peripheral side of the end portion 11 a of the folded portion 11. In plan view, the end 40a on the inner peripheral side of the second sub-plate 40 is located at the same position as the end 30a on the inner peripheral side of the first sub-plate 30, and the end 40b on the outer peripheral side of the second sub-plate 40. Is the same position as the end portion 11 a of the folded portion 11. By inserting and arranging the sub-plates 30 and 40, the thickness tg of the folded portion 11 can be increased, so that the curvature of the rounded portion 11b of the folded portion 11 is increased and the occurrence of cracks can be prevented. Furthermore, the full bead 41 of the second sub-plate 40 can increase the compressibility of the folded portion 11 and prevent the folded portion 11 from sag. A full bead 41 is normally used as the full bead 41 of the second sub-plate 40, but a half bead may be used as long as it can prevent the folded portion 11 from sag. Also, a combination of several beads may be used.

  Further, as shown in FIG. 4, the plate thickness t2 around the cylinder bore hole 2 of the second metal component plate 20A is made smaller than half th of the thickness tg of the folded portion 11. That is, t2 <th (= tg / 2). In addition, since the thickness tg of the folding | returning part 11 becomes thick by insertion arrangement | positioning of the subplates 30 and 40 inside the folding | returning part 11, plate | board thickness t2 around the cylinder bore hole 2 of the 2nd metal component board 20A easily. Can be made smaller than half th of the thickness tg of the folded portion 11.

  Moreover, in the peripheral part of the water hole 3, the 2nd metal structural plate 20A is comprised with the half bead 22A. The convex direction of the half bead 22 </ b> A is formed in the same direction as the convex portion 41 a of the full bead 41 of the second sub-plate 40. The third sub-plate 50 is formed with a half bead 51 having a direction opposite to that of the half bead 22A. The two half beads 22A and 51 are arranged at the same position in plan view. That is, it arrange | positions so that each inclination part of each half bead 22A, 51 may overlap in planar view. Further, the end portion 50 a on the peripheral side of the cylinder bore hole 2 of the third sub-plate 50 is formed to be closer to the outer peripheral side than the end portion 11 a of the folded portion 11.

  Accordingly, in the peripheral portion of the cylinder bore hole 2, the rounded portion 11b of the folded portion 11 of the first metal component plate 10 and the end portion 20Aa of the second metal component plate 20A are aligned, and in the peripheral portion of the water hole 3 The end portions 10b and 20Ab of the first and second metal constituting plates 10 and 20A, and the end portions 30b and 50b of the first sub plate 30 and the third sub plate 50 are aligned.

  According to the cylinder head gasket 1A having the above-described configuration, the second metal component plate 20A is formed at the peripheral portion of the cylinder bore hole 2 even when a large tightening force is generated around the cylinder bore hole 2 due to the thickness. Since the end portion 20Aa enters the rounded portion 11b side of the turned-up portion 11, no large surface pressure is generated at the peripheral portion of the cylinder bore hole 2, and the maximum surface pressure is generated on the outer peripheral side thereof. As a result, excessive sealing pressure is not applied to the peripheral edge of the cylinder bore of the engine, so that deformation of the cylinder bore can be suppressed. That is, by suppressing the maximum value of the surface pressure at the peripheral edge of each cylinder bore hole 2, deformation of each cylinder bore is prevented. Note that the width of the folded portion 11 and the shapes and sizes of the beads 21A and 41 can be obtained from the surface pressure distribution obtained from experiments and calculations.

  Further, when a large tightening force is not applied, an appropriate sealing pressure is also applied to the peripheral portion of the cylinder bore by the folded portion 11 and the full bead 21A, and further, a sealing pressure is applied by a seal line formed by the full bead 21A on the outer peripheral side. Therefore, excellent sealing performance can be exhibited.

  Further, the thickness tg of the folded portion 10 can be adjusted by the first sub plate 30 and the second sub plate 40, and the compressibility of the folded portion 11 can be increased by the full bead 41 of the second sub plate 40, and the folded portion 11 can be increased. Prevents drooling. A full bead 41 is normally used as the full bead 41 of the second sub-plate 40, but a half bead may be used as long as it can prevent the folded portion 11 from sag. Also, a combination of several beads may be used.

  In addition, when the convex portion 21Aa of the full bead 21A of the second metal component plate 20A and the convex portion 41a of the full bead 41 of the second sub plate 40 (contact portion with the first metal component plate) are in the same position in plan view. A larger seal pressure can be generated, and if these two positions are shifted from each other in plan view, a region of a relatively large seal pressure can be widened while reducing the maximum seal pressure.

  With these configurations, even when the upper surface side and the lower surface side of the cylinder head gasket 1 are rubbed and displaced due to external factors such as thermal deformation of the cylinder head or the cylinder block, the tip of the bore An increase in surface pressure at the portion can be suppressed, and indentations and the like generated in the cylinder head and the cylinder block can be reduced.

  In the above description, the full beads 21A and 41 have been described as beads having a circular cross-sectional shape. However, the bead shape is not particularly limited in the present invention, and the cross-sectional shape may be an arc shape, a sine shape (cosine), or a trapezoidal shape. , A triangular (mountain) shape, or the like.

It is a fragmentary sectional view which shows the cylinder head gasket of the 1st Embodiment of this invention. It is a partial expanded sectional view which shows the vicinity of the folding | turning part of FIG. It is a fragmentary sectional view which shows the cylinder head gasket of the 2nd Embodiment of this invention. It is a partial expanded sectional view which shows the vicinity of the folding | turning part of FIG.

Explanation of symbols

1, 1A Cylinder head gasket 2 Cylinder bore hole 10 First metal component plate 11 Folded portion 11a Folded portion end portion 20, 20A Second metal component plate 21, 21A Full bead 21a, 21Aa Full bead convex portion 30 First sub plate 40 Second sub-plate 41 Full bead 41a Full-bead convex portion 50 Third sub-plate t2 Plate thickness around cylinder bore hole in second metal component plate

Claims (4)

  Around the cylinder bore hole, the first metal component plate is formed with a folded portion, and the second metal component plate laminated on the first metal component plate is opposed to a full bead that protrudes from the first metal component plate side. And a convex portion of the full bead is disposed on the inner peripheral side of the end portion of the folded portion, and at least one sub-plate is inserted and disposed inside the folded portion. gasket.   2. The cylinder head gasket according to claim 1, wherein the second metal component plate is laminated on a folded portion side of the first metal component plate.   3. The cylinder head gasket according to claim 1, wherein a thickness of the second metal component plate around a cylinder bore hole is smaller than half of the thickness of the folded portion.   A flat sub-plate on the inner peripheral side of the end portion of the folded portion and a ring-shaped sub plate having a full bead on the inner peripheral side of the end portion of the folded portion are inserted and arranged inside the folded portion. The cylinder head gasket according to claim 1, 2, or 3.

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