JP2009156395A - Metallic gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic gasket capable of enhancing seal performance around a seal target hole by using the pressure of a seal target fluid, arranging a contact pressure adjustment member around the seal target hole, and generating high seal contact pressure, and excellent in seal performance and durability. <P>SOLUTION: In a portion facing the seal target hole 2 of the metallic gasket 1, 1A-1F having two or more metallic composition plates 10, 20 and sandwiched between two members to perform sealing, a U-shaped ring 30 having a cross section protruded on the outer peripheral side is arranged between the two metallic composition plates 10, 20. A portion corresponding to the seal target hole 2 of one metallic composition plate 10 of the two metallic composition plates 10, 20 is folded back, and an end 12a of the folded-back portion 12 is arranged outside the U-shaped ring 30. A communication hole 12b for making the inside of the U-shaped ring 30 communicate with the seal target hole 2 is formed in part of the folded-back portion 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a metal gasket that is sandwiched between two members such as a cylinder head and a cylinder block of an engine for sealing, and more specifically, the pressure of a fluid to be sealed can be used as a seal surface pressure, The present invention relates to a metal gasket that can exhibit excellent sealing performance.

  Metal gaskets such as cylinder head gaskets are fastened with bolts in a state of being sandwiched between two engine members such as a cylinder head of an automobile engine and a cylinder block (cylinder body), and combustion gas, oil, cooling water It has a role to seal fluid such as.

  Recent engines are becoming smaller and lighter than conventional engines, and the material changes from cast iron to aluminum alloy, and the combustion gas pressure tends to increase as the engine output increases. . On the other hand, from the viewpoint of reducing the weight of the engine, the number of metal component plates that can be used for the gasket is decreasing, and it is necessary to exhibit a high seal surface pressure with a small number of metal component plates.

  In the case of a cylinder head gasket, in order to prevent combustion gas that is corrosive at high temperatures from entering between the metal component plates of the gasket, a grommet that is a U-shaped ring or a folded portion that is a folded metal component plate is provided. It has been arranged and used so as to be convex toward the cylinder bore hole side (see, for example, Patent Document 1).

However, in the case of a grommet or folded portion that protrudes toward the cylinder bore hole side, when the pressure of the combustion gas in the hole to be sealed increases, the pressure of the combustion gas causes the cylinder head to move away from the cylinder block. At this time, the pressure of the combustion gas acts in the direction of making the gasket thinner with respect to the grommet and the folded portion. Therefore, there is a problem that the followability of the seal member with respect to the separation of the engine member is deteriorated and the seal performance is deteriorated.
JP 2006-132714 A

  The present invention has been made in view of the above situation, and an object of the present invention is to improve the sealing performance around the hole to be sealed using the pressure of the fluid to be sealed, and to provide a hole to be sealed. An object of the present invention is to provide a metal gasket excellent in sealing performance and durability capable of generating a high sealing surface pressure by arranging a member for adjusting the surface pressure around it.

  In order to achieve the above object, the metal gasket according to the present invention has two or more metal constituent plates, and faces the sealing target hole of the metal gasket that is sandwiched between two members for sealing. A U-shaped ring with a cross section projecting outward is disposed between the two metal component plates, and the seal target hole portion of one metal component plate of the two metal component plates is folded back. In addition, the end portion of the folded portion is disposed outside the U-shaped ring, and a communication hole is provided in part of the folded portion to communicate the inner side of the U-shaped ring with the sealing target hole. Configured.

  One or a plurality of communication holes, for example, 2 to 8, preferably at regular intervals, are provided in the circumferential direction around the sealing target hole of the folded portion. The size of the communication hole is such that the pressure of the fluid in the hole to be sealed follows the pressure fluctuation of the fluid and can be transmitted to the fluid inside the U-shaped ring.

  According to this configuration, the arrangement of the U-shaped ring whose cross section is convex on the outer peripheral side increases the pressure of the fluid to be gas-sealed and counters the fastening force of the member that sandwiches the gasket. When the member sandwiching the gasket is expanded and the pressing force on the gasket decreases, the pressure of the high-pressure fluid is transmitted from the outside of the folded portion through the communication hole into the U-shaped ring, and the U-shaped ring The force that pushes the ring increases, and the metal component plates of the gaskets on both sides sandwiching the U-shaped ring are pressed toward the engine member to maintain the seal surface pressure necessary for sealing. Therefore, the followability in the seal is remarkably improved.

  In addition, when the pressure of the fluid to be sealed is reduced and the pressing force against the gasket due to the fastening force of the member sandwiching the gasket is increased, the end of the folded portion serves as a surface pressure adjusting member and plays a role of a shim Therefore, the thickness around the hole to be sealed can be maintained, and the seal surface pressure generated by this thickness can maintain the seal surface pressure necessary for sealing. At the same time, the U-shaped ring can be prevented from being crushed by the end of the folded portion inserted therein, so that the durability is also increased.

  In addition, when a folded portion is provided around the hole to be sealed and the end portion of the folded portion is arranged outside the other metal component plate, the two metal component plates are separated at the folded portion. Can be prevented. This eliminates the need for spot welding or caulking to prevent the metal component plates from falling apart. Even when the end portion of the folded portion is disposed between the inner side of another metal component plate and the outer side of the U-shaped ring, the function of pressing the U-shaped ring can be achieved.

  In the metal gasket described above, a half bead that opens on the seal target hole side is provided on at least one of the two metal constituent plates sandwiching the U-shaped ring, and the U-shaped ring is disposed inside the half bead. Configure. When this half bead is provided, it becomes easy to dispose a U-shaped ring, and a seal line can be formed with a relatively wide width at the flat part on the seal target hole side of the half bead. The generation can be suppressed, and the sealing function of the half bead is added to improve the sealing performance.

  Said metal gasket WHEREIN: The full bead which protrudes outside is arrange | positioned and comprised in the sealing object hole side part of the said half bead. According to this configuration, a full-bead pressing force can be applied in addition to a half-bead pressing force, so that a seal line with a strong pressing force can be formed.

  Said metal gasket WHEREIN: The full bead which protrudes outside is arrange | positioned and comprised in the seal object hole side part of the said metal structural board. According to this configuration, in addition to the sealing effect of the U-shaped ring and the folded portion, the sealing effect of the full bead is also added, so that higher sealing performance can be obtained.

  According to the metal gasket of the present invention, when the pressure of the fluid to be sealed is increased by disposing a U-shaped ring having a convex cross section on the outer peripheral side and providing a communication hole in the folded portion, The gaskets on both sides holding the U-shaped ring by pressing the U-shaped ring in the opening direction by the pressure of the fluid transmitted from the hole side to the U-shaped ring via the communication hole The metal component plate is pressed in the member direction. Therefore, since the pressure of the fluid to be sealed can be used as the sealing surface pressure, the sealing surface pressure increases and the sealing performance can be improved.

  Also, when the force that the members on both sides press the gasket increases, the end of the folded portion plays the role of a pressure adjusting member similar to the shim, so while preventing the U-shaped ring from being crushed, The thickness around the hole to be sealed can be maintained, and an appropriate seal line can be maintained by the seal surface pressure generated by this thickness.

  Next, an embodiment of a metal gasket according to the present invention will be described with reference to the drawings, taking a cylinder head gasket as an example. 1 to 8 are schematic explanatory diagrams, and the dimensions such as the plate thickness, the size of the hole to be sealed, the size of the folded portion, the size of the bead and the like are shown for easy understanding of the configuration. It is exaggerated, different from the actual one.

  A metal gasket according to an embodiment of the present invention is a cylinder head gasket that is 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, and The fluid such as cooling water and oil in the cooling water passage and cooling oil passage is sealed.

  The cylinder head gasket includes 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

  As shown in FIGS. 1 and 2, the cylinder head gasket 1 according to the first embodiment of the present invention is formed into two metal component plates 10 and 20 and a U-shape whose cross section is convex toward the outer peripheral side. The ring 30 is formed. The first metal component plate 10 and the second metal component plate 20 are formed of, for example, a stainless annealed material, and the U-shaped ring 30 is formed of, for example, a stainless spring steel plate.

  At the peripheral edge of the cylinder bore hole 2, the first metal component plate 10 is provided with a half bead 11 that opens on the cylinder bore hole 2 side, and the second metal component plate 20 is provided with a half bead 21 that opens on the cylinder bore hole 2 side. . A U-shaped ring 30 having a rounded portion (folded portion) 31 on the outer peripheral side is disposed between the two half beads 11 and 21.

  Further, as shown in FIG. 1, the peripheral portion of the sealing target hole 2 of the first metal component plate 10 is folded back, and the end portion 12a of the folded portion 12 is outside the U-shaped ring 30 and the second metal component. Arranged inside the plate 20. With this configuration, the open side of the U-shaped ring 30 enters the folded portion 12. Alternatively, as shown in FIG. 2, the end 12 a of the folded portion 12 is disposed outside the U-shaped ring 30 and outside the second metal component plate 20. With this configuration, the open side of the U-shaped ring 30 enters the inside of the folded portion 12 together with the end portion of the second metal component plate 20.

  Furthermore, a communication hole 12 b is provided in a part of the folded portion 12 to allow the space 40 inside the U-shaped ring 30 to communicate with the sealing target hole 2. The communication hole 12b is provided in the circumferential direction around the sealing target hole 2 of the folded portion 12 by one or plural, for example, two to eight, preferably at equal intervals. The size of the communication hole 12b is such that the pressure P of the combustion gas in the sealing target hole 2 can be transmitted to the fluid in the space inside the U-shaped ring 30 following the pressure fluctuation of the combustion gas. Say it.

  Moreover, the half bead 13 which the water hole 3 side opens in the 1st metal component board 10 is provided also in the water hole 3 side, and the half bead 23 which the water hole 3 side opens in the 2nd metal component board 20 is provided.

  With this configuration, when the pressure P of the combustion gas of the engine increases, as shown in FIGS. 1 and 2, the pressure P of the combustion gas transmitted into the U-shaped ring 30 through the communication hole 12 b causes U Pressure P acts in the direction in which the letter-shaped ring 30 opens, and a force F1 is generated that presses the metal component plates 10 and 20 on both sides holding the U-shaped ring 30 in the member direction. For this reason, the pressure P of the combustion gas can be used as the surface pressure for sealing, so that the sealing performance is improved. Further, the U-shaped ring 30 makes it difficult for the combustion gas to enter between the metal constituent plates 10 and 20 on the outer peripheral side of the U-shaped ring 30, so that the sealing performance is improved, Durability can be improved.

  Further, when the pressure P of the combustion gas of the engine becomes low and a pressing force is generated by the members on both sides pressing the gasket 1 from both sides, the end 12a of the folded portion 12 becomes a pressure adjusting member, which is the same as the shim. Therefore, the thickness of the peripheral portion of the sealing target hole 2 can be maintained, and an appropriate seal line can be maintained by the seal surface pressure generated by the thickness.

  In addition, as shown in FIG. 2, when the folded portion 12 is provided around the seal target hole 2 and the end portion 12 b of the folded portion 12 is disposed outside the second metal component plate 20, the folded portion 12. Therefore, it is possible to prevent the two metal constituent plates 10 and 20 and the U-shaped ring 30 from being separated. This eliminates the need for spot welding and caulking to prevent the metal constituent plates 10 and 20 and the U-shaped ring 30 from falling apart. As shown in FIG. 1, even when the end 12 b of the folded portion 12 is disposed between the inside of the second metal component plate 20 and the outside of the U-shaped ring 30, the U-shaped ring 30. The function of pressing down can be achieved.

  In addition, the U-shaped ring 30 can be easily disposed by the half beads 11, 21, and a seal line can be formed by a relatively wide flat portion on the seal target hole 2 side. And indentation can be suppressed. In other words, recent engine parts made of aluminum alloy have low rigidity and are easily scratched, so that the seal line part is scratched, and the seal performance deteriorates due to the scratch to obtain an appropriate seal performance. There is a problem that cannot be done, but it is a countermeasure against this problem. Furthermore, since the sealing function of the half beads 11 and 21 is added, the sealing performance is further improved.

  A cylinder head gasket 1A according to the second embodiment of the present invention shown in FIG. 3 includes three metal constituent plates 10, 20, 50 and a U-shaped ring 30 whose section is convex toward the outer peripheral side. . In the second embodiment, the third metal component plate 50 is sandwiched between the first metal component plate 10 and the second metal component plate 20 in the first embodiment. Other than this configuration, the second embodiment is the same as the first embodiment shown in FIG.

  When the third metal component plate 50 is disposed, the thickness of the gasket 1A can be easily adjusted, so that the U-shaped ring 30 and the end portions 12a and 22a of the folded portions 12 and 22 are easily disposed. Further, the half beads 11 and 21 need not be provided with a steep slope, and the adjustment of the seal surface pressure by the half beads 11 and 21 is facilitated.

  The cylinder head gasket 1B according to the third embodiment of the present invention shown in FIG. 4 includes three metal component plates 10, 20, and 50 and a U-shaped ring 30 whose section is convex outward. . In the third embodiment, the second metal component plate 20 is not provided in the peripheral portion of the cylinder bore hole 2 without providing the half beads 21 provided on the second metal component plate 20 as in the second embodiment. It is formed flat. A U-shaped ring 30 is disposed between the half bead 11 of the first metal component plate 10 and the flat portion of the second metal component plate 20. Other than this configuration, the second embodiment is the same as the second embodiment. In the third embodiment, since there is one half bead 11 than in the second embodiment, the surface pressure of the seal line can be lowered.

  In the structures of the first to third embodiments, the bore surface pressure can be generated using the pressure P of the combustion gas, but because the engine member is in contact with the relatively wide flat portion, It will not be high surface pressure. Therefore, the impression of the bore portion of the engine member made of aluminum alloy can be reduced. Therefore, it is particularly suitable for an open deck type gasoline engine made of aluminum alloy.

  The cylinder head gaskets 1C and 1D of the fourth and fifth embodiments of the present invention shown in FIGS. 5 and 6 are the same as the cylinder head gaskets 1 and 1A of the first and second embodiments, respectively. Full beads 14 and 24 are provided on the cylinder bore hole 2 side of the half bead 11 of the component plate 10 and the cylinder bore hole 2 side of the half bead 21 of the second metal component plate 20. By forming a seal line having a high seal surface pressure with the full beads 14 and 24, the full beads 14 and 24 can be applied to an engine having a high combustion gas pressure such as a diesel engine.

  The cylinder head gasket 1E of the sixth embodiment of the present invention shown in FIG. 7 is the same as the cylinder head gasket 1B of the third embodiment, on the cylinder bore hole 2 side of the half bead 11 of the first metal component plate 10. A full bead 14 that is convex outward is provided. By forming a seal line with a high seal surface pressure with this full bead 14, it can be applied to an engine having a high pressure of combustion gas such as a diesel engine.

  The cylinder head gasket 1F according to the seventh embodiment of the present invention shown in FIG. 8 is protruded outward from the cylinder bore hole 2 side of the second metal component plate 20 in the cylinder head gasket 1B according to the third embodiment. A full bead 24 is provided. By forming a seal line having a high seal surface pressure with this full bead 24, the full bead 24 can be applied to an engine having a high combustion gas pressure such as a diesel engine.

  In the embodiment shown in FIGS. 5 and 6, the seal surface pressure can be lowered by providing only one of them as in the embodiment shown in FIG. 7 or FIG.

  The configurations of the half beads 11 and 21 and the full beads 14 and 24 are appropriately selected according to the required seal surface pressure. In the above description, the full beads 14 and 24 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.

  Although not particularly illustrated, if a seal ring such as a wire ring is disposed inside the U-shaped ring 30, the U-shaped ring 30 can be U-shaped by the seal ring even when the open side of the U-shaped ring 30 is pressed. The open side of the shaped ring 30 can be prevented from being crushed. Therefore, the open side of the U-shaped ring 30 is crushed, and a gap is generated between the U-shaped ring 30 and the metal component plates 10 and 20 sandwiching the ring 30 on the seal target hole 2 side. Combustion gas can be prevented from entering this gap. Therefore, the sealing performance can be further improved.

It is a fragmentary sectional view which shows the state which has arrange | positioned the edge part of a folding | turning part inside another metal structural board by the cylinder head gasket of the 1st Embodiment of this invention. It is a fragmentary sectional view which shows the state which has arrange | positioned the edge part of the folding | turning part on the outer side of another metal structural board with the cylinder head gasket of the 1st Embodiment of this invention. It is a fragmentary sectional view which shows the cylinder head gasket of the 2nd Embodiment of this invention. It is a fragmentary sectional view which shows the cylinder head gasket of the 3rd Embodiment of this invention. It is a fragmentary sectional view which shows the cylinder head gasket of the 4th Embodiment of this invention. It is a fragmentary sectional view which shows the cylinder head gasket of the 5th Embodiment of this invention. It is a fragmentary sectional view showing a cylinder head gasket of a 6th embodiment of the present invention. It is a fragmentary sectional view showing a cylinder head gasket of a 7th embodiment of the present invention.

Explanation of symbols

1, 1A to 1F Cylinder head gasket 2 Cylinder bore hole 3 Water hole 10 First metal component plate 11, 13, 21, 23 Half bead 12 Folded portion 12a End portion of folded portion 14, 24 Full bead 20 Second metal component plate 30 U Character-shaped ring 40 space 50 third metal component plate (sub-plate)

Claims (4)

  A U-shaped ring having a cross section that protrudes to the outer peripheral side in a portion facing a hole to be sealed of a metal gasket that has two or more metal constituent plates and is sandwiched between two members for sealing. It is disposed between two metal component plates, and a seal target hole portion of one metal component plate of the two metal component plates is folded, and an end portion of the folded portion is outside the U-shaped ring. The metal gasket is further characterized in that a communication hole is provided in a part of the folded portion to connect the inside of the U-shaped ring and the hole to be sealed.   The half-bead which opens a seal object hole side is provided in at least one of the two metal component plates sandwiching the U-shaped ring, and the U-shaped ring is disposed inside the half bead. The metal gasket according to 1.   The metal gasket according to claim 2, wherein a full bead that protrudes outward is disposed at a hole target side portion of the half bead.   The metal gasket according to claim 1, 2, or 3, wherein a full bead that protrudes outward is disposed on a portion to be sealed of the metal component plate.

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