MXPA97009705A - Flexible combustion seal with multip layer packaging - Google Patents

Abstract

The present invention relates to a multilayer gasket for the cylinder head of an internal combustion engine having at least one opening for the cylinder bore, the gasket comprising: a central carrier plate having upper and lower surfaces; The upper plate placed adjacent to the upper surface of the carrier plate, a lower plate placed adjacent to the lower surface of the carrier plate, the carrier plate and the upper and lower plates each have a radially internal edge forming the opening for the orifice. cylinder, a flexible wire ring having a radially external circumference, this ring is directly joined to a plurality of points located along the radially outer circumference to only the inner edge of the carrier plate around the opening of the cylinder when the together is in a state relaxes

Description

FLEXIBLE COMBUSTION SEAL WITH MULTI-LAYER PACKAGING FIELD OF THE INVENTION The present invention relates to a metal rolling cylinder head gasket for an internal combustion engine. More particularly, the invention relates to a multi-layer metal cylinder head gasket having a sealing ring, flexible around a combustion chamber opening in combination with sealing flanges arranged on surface plates positioned radially outwardly. from the sealable, flexible ring.

BACKGROUND OF THE INVENTION Frequently, gaskets are used as a seal between mechanical components that mate. A common application comprises placing the packing between the engine block and the cylinder head of an internal combustion engine. Cylinder head gaskets typically extend around the cylinder bores to provide a combustion seal, keeping the high combustion temperature gases within the cylinder bores. Simultaneously, the packages also seal fluid flow openings such as cooler and oil openings to avoid undesirable mixes. A cylinder head gasket supports charging from a bolted connection of the mechanical components and lies on that load to provide both combustion and fluid flow seals. In a metal rolling package for an internal combustion engine, the package is formed from a plurality of laminated metal plates together. The metal plates provide structural support within the joint between the cylinder head and the engine block, and provide radial resistance for the package to withstand the explosion due to pressure from the combustion chamber. The known packages use any of several types of combustion seals. A type known as an eyelash combustion seal ring is essentially composed of a wire, which generally has a circular cross-sectional area. The cable can be inserted into an open end of a U-shaped flange with the opposite ends of the flange engaging opposite faces of a main packing body around the combustion opening. A clamping load is applied to the flange portion of the gasket at the point of contact, deforming the circumference of the ring to seal the combustion gases that exit. Using such a configuration, the clamping load required for the sealing of the combustion gases is typically higher because the force is distributed between the ring and the flange, and may tend to promote undesirable deformation of the gasket and the engine block. In addition, both the flange combustion aperture and the separated cable ring are subjected to thermal deformation which produce additional plastic deformation which tends to occur under the high operating temperature during the life of the ring. The thermal deformation results in premature packing failure. The flange is also subject to faults along the U-shaped bends due to compression fatigue and environmental conditions. Another type of combustion seal resides on a floating flexible ring installed separately from the packing. The floating ring is installed inside a channel formed around the hole of the combustion chamber. A force applied to such a ring is concentrated at the point of contact, deforming the circumference of the ring to effectively seal the combustion gases. However, such a sealing ring must be installed separately, and can migrate before being subjected to the clamping load, resulting in an imperfect seal. Additionally, the channel that receives the ring must be machined separately in the engine block to accommodate the ring, complicating the manufacture of the packaging.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a cylinder head gasket of an internal combustion engine having at least one cylinder bore opening. The packing is held between a cylinder head and an engine block. A combustion seal for the cylinder head gasket comprises a central carrier plate and at least two surface plates disposed on opposite sides of the central carrier plate. The surface plates include a flange portion located annularly around the combustion openings. A flexible combustion seal ring is located radially inward of the flange portions, and is positioned along an internal peripheral edge of a combustion opening formed in the multi-plate package. The flexible ring is joined along the internal periphery in a discrete number of highly localized points by means of an elastomeric adhesive or by welding. The attachment locations preferably maintain an air gap between the outer periphery of the ring and the internal periphery of the combustion opening prior to the installation of the package. The packaging of the invention provides special advantages when used in heavy-duty diesel engines that have a cast iron liner protruding above the engine block. When a motor is assembled, the packing is placed between the head of the motor cylinder and the block in such a way that the flexible combustion seal ring is oriented around the combustion chamber. As the bolts connecting the head of the cylinder and the block are clamped, the load placed on the package increases. Because the ring of the flexible combustion seal has a thickness greater than the thickness of the multiple layers adjacent to the combustion opening, the pressure of the larger surface is generated on the flexible combustion seal, resulting in sealing cutting forces. upper around the combustion chamber. In addition, because the combustion ring is flexible, it deforms to accommodate variations between the sealing surface, especially on the cylinder liner, resulting in a particularly tight seal. As the ring deforms, it fills the space between the outer circumference of the ring and the internal periphery of the combustion opening in the gasket. The installation load can fracture the localized junctions. However, the ring is deformed to directly contact the internal periphery of the package's combustion opening, thereby receiving the radial support from the multiple layers of the package. The flange section of the gasket, oriented around the combustion chamber opening radially outwardly of the flexible combustion seal, is substantially flattened and provides a secondary seal of the combustion gases and prevents the engine cooler from entering the chamber of combustion. The transport of the packaging of the invention is simplified because the sealing ring is attached directly to the carrier plate. In addition, the connection fixes the sealing ring to a predetermined space relative to the carrier plate. Therefore, the positioning of the carrier plate also suitably places the sealing ring with respect to the carrier plate without expensive machining of the engine block. Additionally, alternative means of securing the ring to the carrier plate, such as a U-shaped flange, are not required. Because the combustion seal comprises a single piece, the holding load to provide an adequate seal is greatly reduced when compared to more conventional packages. The lower clamping loads reduce the deformation of the hole and improve the performance of the motor.

BRIEF DESCRIPTION OF THE DRAWINGS The characteristics and inventive aspects of the present invention will become apparent after reading the following detailed descriptions, claims and drawings of which the following is a brief description: Figure 1 is a perspee view of a metal package of the present invention. Figure 2 is a cross-senal view of a portion of the package in a relaxed state along lines 2-2 in Figure 1. Figure 3 is an enlarged view showing details contained in circle 3, 4 of Figure 2. Figure 4 is an amplified view showing alternative details contained in circle 3, 4 of Figure 2 in a different circumferential location around a combustion chamber hole. Figure 5 is a cross-senal view of the gasket of Figure 2 installed between a cylinder head and the engine block.

DETAILED DESCRIPTION OF A PREFERRED MODALITY.

In Figures 1 to 4 a cylinder head gasket 10 is shown in the relaxed state. As shown in Figure 1, the gasket 10 includes a plurality of holes 11 in the combustion chamber in combination with the bolt holes 12 and the service holes 13. The service holes 13 allow the flow of lubricant or cooler between the cylinder head and the engine block. To seal the cylinder bores of an internal combustion engine, the gasket 10 has an annular flexible combustion seal ring 14 in combination with the flanges 15, wherein the ring 14 is disposed radially inwardly of the flanges 15. The construn of the package 10 around the combustion chamber 5 is shown in greater detail in Figure 2. The package 10 comprises a central carrier plate 20 and at least 2 surface plates 21 and 22 arranged on opposite sides of the central carrier plate 20 . The plate 21 is laminated with respect to an upper surface of the central carrier plate 20, while the plate 22 is laminated with respect to a lower surface of the central carrier plate 20. The surface plates 21, 22 include an outwardly extending flange portion 23 positioned annularly around the combustion opening, forming the flanges 15 that extend outwards. The ring 14 has a thickness "t1" greater than a thickness "t2" of the combined carrier plate 20 and the opposing plates 21, 22 adjacent to the combustion opening 11 forming an internal peripheral rim 24. As best seen in Figures 3 and 4, the ring 0 14 is attached to the peripheral flange 24 of the combustion opening 11 at a discrete number of highly localized points by means of an adhesive or weld 25. The bonding locations preferably maintain an air space "6" between an outer periphery 26 of the seal 14 and the rim 5 24 before the installation of the gasket, as shown in Figure 4. Preferably, the number of located points of the junn 25 between the ring 14 and the rim 24 are equally spaced around the circumferential extension of the bore 11 of the combustion chamber. The number of junns typically is not less than 3 nor greater than 10. More preferably, the number of localized junns is about 6 locations. The extension of the space "G" is a direct funn of the joints 25. The size of the space "G" varies according to the design of the motor because the space "G" allows adequate compression of the seal 14. As illustrated in Figure 5, under the proper compression of the seal ring 14, the space "G" should essentially disappear despite the existence of the joints 25. Because the joints 25 are highly localized, most of the outer circumference of the ring 14 does not contact the joints 25. More particularly, the space "G" disappears when the ring 14 is subjected to pressure between a motor head 30 and a motor block 31. When the package 10 is held in place between the head 30 and the block 31, the ring 14 makes contact with the head and the first block due to greater thickness of the ring 14, resulting in a high clamping pressure. Due to the high clamping pressure, the ring 14 provides a very high level of sealing force. Therefore, since the ring 14 is flexible in nature, it deforms to accommodate any slight variations in the protrusions (not shown) of the adjacent cylinder liner and any variations between the sealing surfaces, resulting in a better adjustment of the seal. As the ring 14 is subjected to pressure, the outer circumference of the ring 14 expands to fill the space "G", providing direct contact between the outer circumference of the ring 14 and the flange 24. The joints 25 can fracture under compression as the ring 14 deforms to directly contact the internal periphery 24 of the combustion opening of the package. However, fracture of the joints 25 after the installation of the seal will not affect the integrity of the combustion seal. After installation, the ring 14 is supported by the flange 24 in a radial direction, increasing the resistance against packing explosion due to the high combustion pressures generated within the engine. The design of the package 10 depends to a large extent on the specific application that is being considered, and can be adjusted in various ways. For example, the number of plates, the selection of materials, and the edge patterns are all functions of the designs of the particular engine and can be varied accordingly. In certain circumstances, the thickness of the flexible combustion ring 14 can be reduced to a thickness less than that of the carrier plate 20 and the edges 15 of the plates 21, 22. The ring 14 can even be reduced to less than I 1. thickness "t2" of the carrier plate 20 and the plates 21, 22 to accommodate a protrusion of the cylinder liner. The composition of the flexible combustion seal is also a function of the engine design. The flexible combustion ring 14 is usually metallic. It can be formed from carbon steel, stainless steel, beryllium-copper alloys, or any other material that has the required material properties. In general, however, the carrier plate 20 and the surface plates 21, 22 are composed of more rigid material than is the ring 14. A preferred material is steel. Additionally, as the flexible combustion seal ring 14 is joined along an internal peripheral rim 24 over the gasket 10, the need for any additional or alternative fastening means, such as a U-shaped flange, is avoided without affect the transportability of the package assembled. Instead of a separate seal ring that is added to the assembly in the installation, the ring 14 remains fixed and can be transported with a carrier plate 20 prior to installation. In addition, the pre-installation position of the ring 14 is fixed by the joints 25 at a predetermined spacing relative to the carrier plate 20. Therefore, the positioning of the carrier plate 20 also adequately locates the seal ring 14 relative to the carrier plate 20 without expensive machining of the engine block, and without the use of a U-shaped flange. seal 14 does not require a U-shaped flange, the clamping load necessary to provide a desired seal is greatly reduced when compared to more conventional packages that require higher clamping loads to achieve the required sealability. The lower clamping loads reduce the deformation of the hole and improve the performance of the motor. Preferred embodiments of the present invention have been described. A person skilled in the art will realize, however, that certain modifications fall within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.

Claims (18)

1. CLAIMS 1 . A cylinder head gasket of an internal combustion engine having at least one cylinder bore opening, the gasket of the cylinder head comprising: a central carrier plate, such a carrier plate having an upper surface and a lower surface; and a flexible cable ring having a radially outer circumference, such a cable ring directly attached to the carrier plate around the opening of the cylinder bore when the package is in a relaxed state.
2. 2. A cylinder head gasket according to claim 1, characterized in that the junction is limited to a plurality of points located along such radially outer circumference.
3. 3. A cylinder head gasket according to claim 2, characterized in that said union comprises one of an elastomer and a weld.
4. 4. A cylinder head gasket according to claim 2, characterized in that the outer circumference is dimensioned to leave a space between such external circumference and such opening of the cylinder bore when the gasket is in the relaxed state.
5. 5. A cylinder head gasket according to claim 2, characterized in that the points are equally circumferentially spaced along the radially outer circumference.
6. 6. A cylinder head gasket according to claim 5, characterized in that the number of points is between 3 and 10.
7. 7. A cylinder head gasket according to claim 6, characterized in that the number of points is approximately 6.
8. 8. A cylinder head gasket according to claim 1, characterized in that the gasket further includes an upper plate and a lower plate, such carrier plate and such plates having a radially internal flange forming the opening of the cylinder bore, wherein the upper plate is laminated with respect to the upper surface of the carrier plate and the lower plate is laminated with respect to the lower surface of the carrier plate, such plates further include flange portions disposed radially outwardly of such an inner edge.
9. 9. A cylinder head gasket according to claim 8, characterized in that the ring has a thickness greater than a combined thickness of the plates.
10. 10. A cylinder head gasket of an internal combustion engine having at least one cylinder bore opening, the cylinder head gasket characterized in that it comprises: a central carrier plate, the carrier plate having an upper surface and a lower surface and a thickness between them; and a flexible cable ring having a radially outer circumference and a thickness greater than such a thickness of the carrier plate, the cable ring directly attached to the carrier plate around the opening of the cylinder bore when the package is in a relaxed state . eleven .
11. A cylinder head gasket according to claim 10, characterized in that the junction is limited to a plurality of points located along the radially outer circumference. 1 2.
12. A cylinder head gasket according to claim 11, characterized in that the union comprises one of an elastomer and a weld.
13. A cylinder head gasket according to claim 11, characterized in that the outer circumference is dimensioned to leave a space between the outer circumference and the inner edge when the gasket is in a relaxed state.
14. 14. A cylinder head gasket according to claim 13, characterized in that the points are equally circumferentially spaced along said outer circumference.
15. 15. A cylinder head gasket according to claim 14, characterized in that the number of points is between 3 and 10.
16. 16. A cylinder head gasket according to claim 15, characterized in that the number of points is approximately 6.
17. 1 7. A cylinder head gasket of an internal combustion engine having at least one cylinder bore opening, the cylinder head gasket characterized in that it comprises: a central carrier plate, such a carrier plate having an upper surface and a lower one; an upper and a lower plate, such a carrier plate and such plates having a radially internal edge that forms such an opening of the cylinder bore, wherein the upper plate is laminated with respect to the upper surface of the carrier plate and the lower plate is laminated to the lower surface of the carrier plate, the upper plate and the lower plate in combination with the carrier plate define a thickness of the packing along the radially inner flange, the plates include flange portions disposed radially outwardly from the inner edge; and a flexible cable ring, such a cable ring having a radially outward circumference and a thickness greater than the thickness of the plates, the outer circumference dimensioned to leave a space between the outer circumference and the opening of the cylinder bore when the packing is in a relaxed state, the cable ring directly attached around the opening of the cylinder bore when the package is in a relaxed state, the joint limited to a plurality of points located along the circumference radially outward, the stitches equally circumferentially spaced around the radially outer periphery.
18. 18. A cylinder head gasket according to claim 17, characterized in that the union comprises one of an elastomer and a weld.