JP2005106223A - Laminated metallic gasket and gasket substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated metallic gasket capable of reducing the thickness of its whole, restraining increase in strain, and dislocation stress of a jointed surface of a member to be sealed, and capable of well exhibiting a sealing function. <P>SOLUTION: In this laminated metallic gasket which is provided by laminating a plurality of sheets of metallic plates 2 and producing seal coating layers 3, 4 formed out of rubber or synthetic resin respectively between outer surfaces of its front and rear facing the member to be sealed and metallic plates, the seal coating layer 4 between the layers is formed into a thinner shape than the seal coating layer 3 of the outer surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminated metal gasket that is used mainly at a joint portion between a cylinder head and a cylinder block of an engine, and a gasket substrate suitable for the construction of the laminated metal gasket.

  For example, as a gasket to be used by interposing between a sealed member such as an engine cylinder head and a cylinder block, a metal plate such as stainless steel having elasticity is used as a base material. There is known a so-called metal gasket in which a hole such as a liquid passage hole is provided and a bead is formed around the hole as necessary to ensure a surface pressure.

  Such a metal gasket may have a single metal plate as the substrate, but is usually used by laminating a plurality of the metal plates. In the case of this laminated metal gasket, a seal coating layer made of a coating layer of heat-resistant rubber or synthetic resin is provided between the outer surfaces of the front and back surfaces which are the contact surfaces with the member to be sealed and between the metal plates. The surface roughness of the joint surface of the seal member is absorbed to perform a predetermined seal function as a micro seal and also to perform a seal function between layers (for example, Patent Document 1 below).

About the thickness of the sealing coating layer of the outer surface of the conventional laminated metal gasket, and the sealing coating layer of an interlayer, it is normally set to the substantially same thickness within the range of about 10-200 micrometers.
JP 2002-54740 A

  By the way, the cylinder head and cylinder block of an engine are formed of aluminum alloy or the like, and the surface roughness of the joint surface (joint flange surface, etc.) is in comparison with that of a metal plate made of stainless steel as a base material for a metal gasket. Therefore, it is desirable that the thickness of the seal coating layer is set to be relatively large so that the surface roughness can be absorbed. If the thickness of is also set large, the thickness of the entire laminated metal gasket becomes large. As the overall thickness of the gasket increases, the heat conduction between the sealed members, that is, the heat conduction between the cylinder head and the cylinder block, is cut off. As a result, the temperature difference between the cylinder head and the cylinder block increases. This may cause problems such as increased distortion of the joint surface (joint flange surface) and increased shear stress.

  In addition, when the thickness of the seal coating layer between layers increases, the seal surface pressure decreases due to sagging due to tightening during use (compression of deformation due to tightening) or loss of tightening pressure, resulting in a decrease in seal characteristics. There is also.

  The present invention has been made in view of the above, the thickness of the entire gasket can be set thin, the increase in distortion and shear stress of the joint surface of the member to be sealed can be suppressed, and the sealing function as a micro seal is good. The present invention provides a laminated metal gasket that can be used in the present invention, and a gasket substrate used for this.

  The laminated metal gasket of the present invention made to solve the above-mentioned problems is formed by laminating a plurality of metal plates, and between the outer surfaces of the front and back metal plates in contact with the member to be sealed and between the metal plates. In the gasket having a laminated structure in which a seal coating layer made of a coating layer is provided, the interlayer seal coating layer is formed thinner than the seal coating layer on the outer surface. As the seal coating layer, a coating layer of rubber or synthetic resin that can form a coating with a very thin thickness is preferably used.

  According to this laminated metal gasket, the thickness of the seal coating layer between the metal plates is formed thinner than the thickness of the seal coating layer on the outer surface of the front and back metal plates, so that the seal coating layer on the outer surface of the front and back surfaces is formed. Even if the thickness of the gasket is set to be relatively thick so that the surface roughness of the joint surface of the member to be sealed can be absorbed as in the conventional case, the thickness of the entire gasket can be made smaller than in the past.

  For this reason, the degree of heat conduction between the two sealed members to be joined is reduced, and an excessive temperature difference between the two sealed members can be suppressed, and distortion of the joint surface caused by the temperature difference can be suppressed. An increase or an increase in shear stress can be prevented. In addition, since the thickness of the interlayer seal coating layer is small, no sagging occurs due to tightening, and it is possible to prevent a decrease in seal surface pressure and a decrease in seal characteristics due to a loss of the tightening pressure. In particular, the metal plate made of stainless steel or the like has a considerably high finishing accuracy of the surface compared to the joining surface of the sealed member such as an aluminum alloy, and therefore, even if the thickness of the seal coating layer between the layers is set thin, There is no risk of impairing the sealing performance between the layers.

  In the laminated metal gasket, at least one of the front and back metal plates may be provided with a seal coating layer on the outer surface and a seal coating layer between the layers on both sides. For example, in the case of a laminated metal gasket in which three or more layers of metal plates are laminated, the front and back metal plates are respectively provided with the seal coating layer on the outer surface and the seal coating layer between the layers on both sides thereof. Thus, at least one intermediate metal plate can be made of a material having no seal coating layer. In this case, the above-mentioned laminated metal gasket can be constituted by using a metal plate without a seal coating layer as it is as the intermediate layer.

  Furthermore, as said laminated metal gasket, at least one metal plate of the front and back can also consist of what provided the sealing film layer of the said outer surface only on one side. For example, in the case of a laminated metal gasket in which three or more metal plates are laminated, the front and back metal plates are formed by providing the outer surface seal coating layer only on one side, and at least one metal in the middle The plate can be composed of a double-sided seal coating layer on both sides. As a result, the front and back metal plates only need to be coated on one side, and at least one intermediate metal plate needs to be coated on both sides with the same thickness.

  In the laminated metal gasket, it is preferable to set the thickness of the seal coating layer on the outer surfaces of the front and back surfaces to 15 to 30 μm and the thickness of the interlayer seal coating layer to 15 μm or less.

  That is, if the thickness of the seal coating layer on the outer surface of the front and back surfaces exceeds 30 μm, a uniform thickness cannot be obtained by one coating, and if it is less than 15 μm, the surface roughness of the joint surface of the member to be sealed made of an aluminum alloy or the like Cannot be absorbed, and the micro-seal function may be impaired. Therefore, from the viewpoint of these effects, the range of 20 to 25 μm is more preferable.

  On the other hand, if the thickness of the sealing film layer between the layers exceeds 15 μm, the effect of reducing the thickness of the entire gasket cannot be obtained sufficiently. In particular, when the metal plate is made of stainless steel, the finishing accuracy of the surface is considerably higher than the joining surface of the member to be sealed. For example, the surface roughness is about 1 to 2 μm, so that this surface roughness can be absorbed. In the range of about 15 μm or less, it is particularly preferable in practice to set it in the range of 2 to 10 μm. Of course, implementation outside the above range is also possible depending on the material of the metal plate and the finishing accuracy of the surface.

  In addition, the present invention provides a gasket substrate used for at least one of the front and back plates of the above-mentioned laminated metal gasket, with a metal plate as a base material and a seal coating layer provided on both sides thereof, and one side surface in contact with another metal plate The thickness of the seal coating layer is made thinner than the thickness of the other side surface. In this case, it is preferable that the thickness of the seal coating layer on one side is 15 μm or less and the thickness of the seal coating layer on the other side is 15 to 30 μm.

  By using this gasket substrate on at least one of the front and back surfaces of the laminated metal gasket with the larger thickness of the seal coating layer as the outer surface, the laminated metal gasket can be easily constructed and manufactured, The implementation becomes easy.

  According to the laminated metal gasket and gasket substrate of the present invention, the thickness of the entire gasket can be set thin, the increase in distortion and shear stress of the joint surface of the member to be sealed can be suppressed, and the sealing function as a micro seal is also good. Can hold.

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

  1 is a schematic plan view illustrating a gasket according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG. 1, and FIGS. 3 to 5 are partial views illustrating other embodiments. It is an expanded sectional view.

  In the figure, 1 is a laminated metal gasket according to the present invention used for a cylinder head gasket, and has holes such as a combustion chamber 11, a hole for cooling water (not shown) and a bolt insertion hole 12 for tightening, As is well known, a folded portion 13 and stepped or mountain-shaped beads (not shown) for securing a surface pressure during tightening are formed around each hole.

  As shown in FIGS. 2 to 5, the laminated metal gasket 1 includes a plurality of metal plates 2, 2... Made of elastic metal such as stainless steel, and a cylinder head and a cylinder block to be joined. A seal coating layer 3 made of a coating layer of heat-resistant rubber or synthetic resin, respectively, on the outer surfaces of the front and rear surfaces that are in contact with a member to be sealed (not shown), and between the metal plates 2 and 2; In particular, the seal coating layer 4 between the layers is formed thinner than the seal coating layer 3.

  In the configuration of the laminated metal gasket 1, the metal plate 2 is used as a base material, and coating layers such as rubber or synthetic resin are provided on both sides thereof, and the coating layer on one side is sealed to the outer surface. A gasket substrate 5 having a three-layer structure in which the coating layer 3 is formed and the coating layer on the other side is formed thinner than the sealing coating layer 3 on the one side as the sealing coating layer 4 between the layers is used on at least one side of the gasket. Is preferred.

  For example, as shown in FIG. 2, the gasket substrate 5 having the three-layer structure and the second gasket base having the two-layer structure in which the coating layer corresponding to the seal coating layer 3 on the outer surface is provided only on one surface of the metal plate 2. By using two sheets of the material 6 and laminating each of the gasket base materials 5 and 6 with the seal coating layer 3 side as the outer surface, the metal plate 2 of the present invention has a two-layer laminated metal gasket 1. Can be configured.

  Further, as in the embodiment of FIG. 3, two sheets of the gasket substrate 5 having the three-layer structure are used, and an intermediate metal plate 2a having no seal coating layer is interposed between the two substrates 5 and 5. The laminated metal gasket 1 composed of the three metal plates 2 is formed by laminating the thin seal coating layers 4 and 4 of the gasket substrates 5 and 5 so as to be in contact with the intermediate metal plate 2a. Can be configured. Further, as in the embodiment of FIG. 4, a thin wall corresponding to the thin seal coating layer 4 between the first gasket substrate 5 and the second gasket substrate 6 on one side of the metal plate 2. It is also possible to use a third gasket substrate 7 provided with a coating layer.

  In addition to the above, as in the embodiment of FIG. 5, two second gasket substrates 6 having a two-layer structure in which the seal coating layer 3 is formed on the outer surface having a large thickness on one side surface are used. A fourth gasket substrate 8 provided with a thin coating layer corresponding to the interlayer seal coating layer 4 on both surfaces of the metal plate 2 is used as an intermediate layer, and the gasket substrate 8 is interposed between the gasket substrates 6 and 6. And can be laminated.

  As described above, the first, second, third and fourth gasket substrates 5, 6, 7 and 8, the intermediate metal plate 2a and the like are appropriately combined to form the seal coating layer 4 between the metal plates on the outer surface. By laminating so as to be thinner than the seal coating layer 3, it is possible to implement the laminated metal gasket 1 having various laminated structures. From the viewpoint of ease of manufacture and cost, it is preferable to use the first gasket substrate 5 on at least one of the front and back sides.

  In each of the above embodiments, as the metal plate 2, stainless steel such as SUS301H or SUS304 is preferably used, and the thickness t2 is normally set appropriately within a range of 0.1 to 0.5 mm.

  In addition, the seal film layer 3 on the outer surface and the interlayer seal film layer 4 with the coating layer of rubber or synthetic resin, such as silicon rubber or fluorine-based resin having excellent resilience and elasticity such as heat resistance and oil resistance. Rubber or synthetic resin is preferably used. Regarding the thicknesses t3 and t4 of the seal coating layers 3 and 4 made of rubber or the like, the metal plate 2 made of stainless steel or the like has a surface finishing accuracy on the joint surface of a member to be sealed such as a cylinder head or cylinder block made of an aluminum alloy or the like. By contrast, the interlayer sealing film layer 4 can be made considerably thinner than the outer surface sealing film layer 3.

  In practice, the thickness t3 of the seal coating layer 3 on the front and back outer surfaces is set to 15 to 30 μm, more preferably 20 to 25 μm, and the thickness t4 of the interlayer seal coating layer 4 is set to the seal coating layer 3 The thickness is suitably set in the range of 15 μm or less, more preferably 2 to 10 μm.

  According to the laminated metal gasket 1 of the present invention configured as described above, the thickness t4 of the seal coating layer 4 between the metal plates is formed to be thinner than the thickness t3 of the seal coating layer 3 on the front and back outer surfaces. Therefore, even if the thickness t3 of the seal coating layer 3 on the outer surfaces of the front and back surfaces is set to be relatively thick so that the surface roughness of the joint surface of the member to be sealed can be absorbed as in the conventional case, the laminated metal gasket The total thickness of 1 can be made smaller than before.

  For this reason, the degree of heat conduction between the two sealed members to be joined is reduced, and an excessive temperature difference between the two sealed members can be suppressed, and distortion of the joint surface caused by the temperature difference can be suppressed. An increase or an increase in shear stress can be prevented. In addition, since the thickness of the sealing film layer 4 between layers is small, no sagging occurs due to tightening, and it is possible to prevent a decrease in seal surface pressure and a decrease in sealing characteristics due to a loss of the tightening pressure.

  In particular, in the case of the metal plate 2 made of stainless steel, the finish accuracy of the surface is considerably higher than the joining surface of the sealed member such as an aluminum alloy, so the thickness of the sealing film layer between the layers is set to be very thin. However, there is no risk of impairing the sealing performance between the layers, and the present invention can be implemented without any problem.

  The gasket of the present invention can be suitably used as a cylinder head gasket that is used at a joint between an engine cylinder head and a cylinder block.

1 is a schematic plan view illustrating a gasket according to an embodiment of the present invention. It is an expanded sectional view of the AA line of FIG. It is a partial expanded sectional view which shows another Example. It is a partial expanded sectional view which shows other Example. Furthermore, it is a partial expanded sectional view which shows another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gasket 2 Metal plate 2a Intermediate metal plate 3 Seal coating layer on outer surface 4 Seal coating layer between layers 5 First gasket substrate 6 Second gasket substrate 7 Third gasket substrate 8 Fourth gasket substrate 11 Combustion chamber 12 Bolt insertion hole 13 Folded part

Claims (8)

A gasket having a laminated structure in which a plurality of metal plates are laminated, and a seal coating layer made of a coating layer is provided between the outer surfaces of the front and back metal plates that are in contact with the member to be sealed and between the metal plates. In
The laminated metal gasket, wherein the interlayer seal coating layer is formed thinner than the outer surface seal coating layer.   2. The laminated metal gasket according to claim 1, wherein at least one of the front and back metal plates is provided with a seal coating layer on the outer surface and a seal coating layer between the layers on both surfaces.   Three or more layers of metal plates are laminated, and the front and back metal plates each have a seal coating layer on the outer surface and a seal coating layer between the layers on each side, and at least one intermediate plate The laminated metal gasket according to claim 2, wherein the metal plate has no seal coating layer.   The laminated metal gasket according to claim 1, wherein at least one of the front and back metal plates is provided with a seal coating layer on the outer surface only on one side.   Three or more metal plates are laminated, and the front and back metal plates are formed by providing the outer surface seal coating layer only on one side, and at least one intermediate metal plate has an interlayer seal on both sides. The laminated metal gasket according to claim 4, comprising a coating layer.   The laminated metal gasket according to any one of claims 1 to 5, wherein a thickness of the seal coating layer on the outer surfaces of the front and back surfaces is 15 to 30 µm, and a thickness of the interlayer seal coating layer is 15 µm or less.   It is a gasket board | substrate used for at least one of the front and back in the laminated metal gasket of any one of Claims 1-6, Comprising: A sealing film layer is provided in the both surfaces by using a metal plate as a base material, A gasket substrate, wherein the thickness of the seal coating layer is formed thinner than the thickness of the seal coating layer on the other side surface. The gasket substrate according to claim 7, wherein the thickness of the seal coating layer on one side is 15 μm or less and the thickness of the seal coating layer on the other side is 15 to 30 μm.

Images