JP3549016B2 - gasket - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gasket mounted between two members such as a cylinder head and a cylinder block of an internal combustion engine, or between an intake manifold and a cylinder block, and more particularly, from a flexible coating layer having rubber-like elasticity. A gasket having a seal line.
[0002]
[Prior art]
Gaskets used for automobile engines are provided with cylinder bore holes, water holes, oil holes, bolt holes, etc., depending on the application, and various sealing means are provided for each sealing target hole. Is provided.
[0003]
In the cylinder head gasket A as shown in FIG. 1, a hole Hc for a cylinder bore, a water hole Hw, an oil hole Ho, a bolt hole Hb, a push rod hole Hp, and the like are formed. When the engine is operated, combustion gas in a high-pressure and high-temperature state is generated in the cylinder bore, so it is particularly important to seal this part.Bolts for fixing the engine member together with the gasket must be secured around the cylinder bore. For sealing, it is usually arranged so as to surround the cylinder bore hole Hw.
[0004]
Therefore, in the holes other than the cylinder bore hole Hc, that is, in the liquid holes such as the water hole Hw and the oil hole Ho, an equal tightening pressure cannot be received at the time of bolt tightening. The gap between the gasket A and the engine member that sandwiches the gasket A is uneven at the part separated from the gasket A, and the sealing surface pressure at the part separated from the gasket A is reduced, so that sealing cannot be performed well.
[0005]
Further, in the gasket B or the like of the chain case as shown in FIG. 4, since a large sealing surface pressure is not required for sealing the sealing hole Hs, the interval between the bolt holes Hb is large, and a uniform tightening pressure can be received. However, there is a problem that the gap between the gasket B and the member holding the gasket B becomes uneven, resulting in poor sealing performance.
[0006]
Therefore, a coating layer having a predetermined width is provided around the holes Hw, Ho, and Hs to be sealed to compensate for the gap, and the gasket surface is brought into close contact with the joining surface to equalize the sealing surface pressure and improve the sealing performance. The gain is being made.
[0007]
As the coating layer having the predetermined width, there are a layer using a soft material having rubber-like elasticity and a layer using a hard material such as a hard synthetic resin. However, there are problems described below.
[0008]
[Problems to be solved by the invention]
In other words, when the flexible coating layer receives expansion and contraction forces due to large pressure fluctuations and temperature changes, it causes a so-called flow in which creep and material flow toward the lower compression force, and furthermore, compresses and breaks, which is effective. There is a problem that it is impossible to form a simple seal line.
[0009]
For example, in the gasket disclosed in Japanese Patent Application Laid-Open No. 8-338532, in a gasket of a thermosetting resin molded product, both sides of an annular packing layer having a rubber-like elasticity for improving sealing properties are integrally formed with a main body of the gasket. A compression regulating stopper is provided to regulate the amount of compression of the packing layer to prevent compression breakage.
[0010]
However, in this gasket, the effective thickness of the flexible packing layer is reduced by the compression restricting stoppers on both sides, so that the sealing effect is small, and the portion protruding from the compression stopper is easily damaged, resulting in poor durability. There's a problem.
[0011]
In the metal gasket disclosed in Japanese Patent Application Laid-Open No. 9-148787, a hard synthetic resin layer such as an epoxy resin layer is filled in the inner space of the inner bead, and the filling height of the hard synthetic resin layer is adjusted so that the sealing is performed. Surface pressure is equalized.
[0012]
However, in the case of this hard synthetic resin layer, since it does not have sufficient flexibility, it is difficult to adjust the filling height, a relatively large sealing surface pressure is required, and sufficient There is a problem that it is not suitable for obtaining a good sealing performance.
[0013]
Further, in a gasket having a coating layer disclosed in Japanese Utility Model Registration No. 2513947, a ring-shaped hard resin coating layer for generating a sealing surface pressure is formed, and a gasket on both sides of the gasket and a periphery thereof at a portion corresponding to the ring. In addition, a soft coating layer for filling small scratches such as tool marks and cutter traces is provided as a gasket surface layer.
[0014]
However, even in a configuration in which the ring-shaped hard resin coating layer is covered with a soft coating layer, the sealing surface pressure is slightly generated by the soft coating layer, but mainly because the sealing surface pressure is generated by the hard resin coating layer. In addition, it is not suitable for obtaining sufficient sealing performance at a portion where the surface pressure is relatively small, and furthermore, since a soft coating layer is exposed, problems such as creep and flow cannot be avoided.
[0015]
The present invention has been made to solve these problems, and an object of the present invention is to provide a gasket having a relatively large gap with a member that sandwiches the gasket, a relatively small sealing surface pressure, and a non-uniformity. Accordingly, it is an object of the present invention to provide a gasket which can seal a portion which is difficult to seal well and which has excellent durability.
[0016]
[Means for Solving the Problems]
The gasket according to the present invention is configured as follows.
Surrounds the opening hole H provided in 1) gasket configuration plate 20, to form a band-like elastic layer 24 on the formation plate 20, together with the construction plate 20 near the elastic layer 24, from the elastic layer 24 in gasket was also covered with a covering layer 25 of a hard synthetic resin material, the elastic layer 24 is NBR rubber, fluorine rubber, a rubber-based material such as silicone rubber, also the covering layer 25, epoxy resin, silicone resin, Using a soft synthetic resin material such as fluororesin , the component plate 20 has both ends folded back to one side to form a gap between both ends, and the both ends are position holding members 20a, An elastic layer 24 is disposed in the gap so as to protrude from a surface of the position holding member 20a, and a coating layer 25 is further laminated so as to cover the surface of the elastic layer 24 and the position holding member 20a. .
2) Band-shaped elastic layers 24A and 24B are formed around the opening holes H provided in the gasket component plates 20A and 20B, and the elastic layers 24A and 24B are hardened together with the periphery and are harder than the elastic layers 24A and 24B. In the gasket covered with the resin coating layers 25A and 25B, the elastic layers 24A and 24B are rubber-based materials such as NBR rubber, fluoro rubber, and silicone rubber, and the coating layers 25A and 25B are made of epoxy resin. A soft synthetic resin material such as silicone resin or fluororesin is used. Position holding members 27A and 27B made of separate strips are arranged on the gasket component plates 20A and 20B. , 27B, the elastic layers 24A, 24B are arranged so as to protrude from the surfaces of the position holding members 27A, 27B in the gaps formed at the opposite ends of the positions, and The elastic layer 24A, 24B and the position retaining member 27A, the coating layer 25A covering the surface of 27B, is characterized in that a laminate of 25B.
[0017]
In other words, a seal zone (seal line) that surrounds the opening hole and generates a seal surface pressure is provided by coating a flexible elastic and deformable band-shaped elastic layer to prevent creep and flow of the elastic layer. For this purpose, the elastic layer is covered with a film layer of a relatively soft synthetic resin such as an epoxy resin, and the lid is covered.
[0018]
As a material forming the elastic layer, a rubber-based material such as NBR rubber, fluorine rubber, or silicone rubber can be used. As a synthetic resin material harder than the elastic layer forming the coating layer, epoxy resin, A soft synthetic resin material such as a silicone resin or a fluorine resin can be used.
[0019]
The coating layer is formed with such a hardness and thickness as to be deformed without being damaged when pressed. This coating layer is preferably formed to have a hardness of about H-3H and a thickness of about 5-30 μm.
[0020]
In other words, this hard coating film has a softness enough to be crushed, but is not broken even when pressed at the time of tightening, is allowed to be slightly deformed, and is formed so as not to hinder the sealing effect of the elastic layer.
[0021]
Further, the constituent plate of the gasket may be formed of a single plate, or may be formed of a plurality of laminated plates, and may have a coating other than the elastic layer and the coating layer. Good.
[0022]
According to the gasket of this configuration, the flexible elastic layer is deformed even in a portion where the tightening pressure is relatively small, so that the gap between the member and the gasket is filled, and a substantially uniform sealing surface pressure is generated around the opening hole. I do.
[0023]
In other words, when the sealing zone is pressed by the member holding the gasket, the coating layer is harder than the elastic layer, but is a thin film made of synthetic resin, and the inner side is formed of an elastic material. Deform according to. Further, since the elastic layer wrapped in the coating layer is deformable and elastic, a seal surface pressure effective for sealing is generated around the opening.
[0024]
On the other hand, even if this elastic layer is pressed, it is covered with the film layer and is confined, so that no creep or flow occurs.
2) Further, in the above gasket, by disposing the position holding members on both sides of the elastic layer, deformation of the elastic layer in the plane direction of the gasket is prevented by the position holding members together with the coating layer. Therefore, the flow of the elastic layer is more effectively prevented.
[0025]
3) In the gasket described above, since the elastic layer is formed on the groove provided in the component plate, the thickness of the elastic layer increases, and the amount of deformation can be increased, thereby improving the sealing performance.
4) In the gasket described above, if the elastic layer is formed on the component plate by printing, an elastic layer having a complicated shape can be easily formed, and the layer thickness can be changed by multiple printing, so that the gasket can be formed. It becomes easy to form an elastic layer having an appropriate thickness according to each part of the gasket.
[0026]
Further, according to the multiplex printing, the elastic layer and the coating layer can be formed in various shapes and thicknesses, and the multiplex structure can be easily formed.
Therefore, the gasket having the above configuration cannot be used in a place where a strong surface pressure is generated or exposed to a high temperature, for example, a cylinder bore hole or the like. It can be used for various gaskets such as liquid holes such as water holes and oil holes of cylinder gaskets, gaskets for intake manifolds and gaskets for chain cases.
[0027]
In addition, since the elastic layer is protected by the coating layer, the material of the elastic layer can be selected without taking into consideration problems such as creep and flow, so that the range and shape of usable materials are widened. In addition, since the dimensional accuracy of the elastic layer may be rough, the manufacturing is easy.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings, taking a cylinder gasket of an engine and a gasket for a chain cover as examples.
[First Embodiment]
As shown in FIG. 1, an opening hole such as a cylinder bore hole Hc, a water hole Hw, an oil hole Ho, a bolt hole Hb, and a push rod hole Hp is formed in the cylinder head gasket A of the engine.
[0030]
The seal zones 11, 12, and 13 (hereinafter, referred to as 11) are not holes Hc for cylinder bores for sealing high-temperature and high-pressure combustion gas, but are water holes Hw, oil holes Ho, and push rod holes which are low in pressure at a relatively low temperature. It is provided around Hp (hereinafter referred to as opening hole H).
[0031]
As shown in FIG. 2, the sealing zone 11 is formed by a band-shaped elastic layer 14 surrounding the opening H, and a coating layer 15 covering the elastic layer 14 and the component plate 10.
[0032]
The elastic layer 14 is formed by applying a rubber-based material to a predetermined shape by screen printing, but in the case of a material having a low viscosity, it is necessary to coat the material using a means such as spraying or coating. You can also.
[0033]
The material of the elastic layer 14 is preferably a material which has excellent durability and heat resistance with respect to a sealing liquid (gasoline, lubricating oil, water) and the like, has flexibility, and has good resilience to compressive deformation. Rubber materials such as rubber, fluorine rubber, silicone rubber, hydrogenated nitrile / butadiene rubber, and the like can be used.
[0034]
Then, the coating layer 15 covering the elastic layer 14 and the component plate 10 around the elastic layer 14 is formed by coating a relatively soft resin material. The coating layer 15 is formed with such a hardness and thickness as to be deformed without being damaged when pressed.
Since a soft material can be applied by printing, it can be formed in various shapes, and the thickness can be arbitrarily set by multiple printing or the like.
[0035]
As a synthetic resin material harder than the elastic layer forming the film layer, a relatively soft and soft synthetic resin material such as an epoxy resin, a silicone resin, and a fluororesin can be used. That is, a relatively soft resin such as an epoxy resin is used as the resin instead of a hard resin such as a phenol resin.
[0036]
For example, the elastic layer 14 has a hardness of B to 4B and a thickness of 10 μ to 100 μ, and the coating layer 15 has a hardness of H to 3H and a thickness of 5 μ to 30μ.
[0037]
In the case of epoxy resin, it can be applied thick without using a solvent and without leaving bubbles, and has a hardness that does not substantially deform at room temperature, and furthermore has heat resistance and LLC resistance. Easy to use because of excellent oil resistance.
[0038]
In addition, as a material of the component plate 10 of the gasket A, a hard metal such as spring steel or a plastic metal such as copper or aluminum can be appropriately used.
[0039]
In FIG. 2, the elastic layer 14 is formed on a flat portion of the component plate 10. However, as shown in FIG. 3, a bead portion 16A is provided at a position where the elastic layer 14A is provided, and the elastic portion 14 It is also possible to provide the layer 14A and further coat the coating layer 15A.
[Second embodiment]
Next, a gasket B mounted between the cylinder block and the chain case as shown in FIG. 4 will be described.
[0040]
In the gasket B shown in FIG. 4, a band-shaped elastic layer 24 surrounding an opening Hs is formed on a component plate 20 in which an opening Hs is formed of a composite material or metal in which organic or inorganic fibers are fixed with a binder such as rubber. There is provided a sealing zone 21 formed by an elastic layer 24 and a coating layer 25 covering the component plate 20.
[0041]
To give an example of the elastic layer 24 and the coating layer 25, the hardness of the elastic layer 24 is B to 4B, the thickness thereof is 10 μm to 100 μm, and the hardness of the coating layer 25 is Has a thickness of H to 3H and a thickness of 5 to 30 µ.
[0042]
Further, position holding members 20a are provided on both sides of the elastic layer 20. The position holding member 20a shown in FIG. 5 is formed by folding the component plate 20 of the gasket B, but using a band plate different from the component plate 20A like the position holding member 27A shown in FIG. It can also be formed. In FIG. 6, the band plate is folded and doubled. However, the band plate may be formed by one sheet or a plurality of sheets.
[0043]
Further, in FIG. 7, a position holding member 27B having a bead portion 27Bb is provided on both sides of the seal zone 21B.
Further, as shown in FIG. 8, the elastic layer 24C can be formed on the groove 28C formed in the component plate 20C.
[0044]
FIG. 9 shows a modified example of the gasket component plate 30, the elastic layer 34, and the coating layer 35. (A) shows a bead plate 39, (b) shows a coating layer 40A, and (c) shows a sub plate 41B having a folded portion. Further, (d) has a gourmet 42C, an elastic layer 34C and a coating layer 35C on both surfaces, and (e) has an elastic layer 34D provided along an end of the component plate 30D.
[0045]
〔effect〕
According to the gaskets A and B having the above configuration, the flexible elastic layers 14, 24 and 34 forming the seal zones 11, 21 and 31 are deformed even at a portion where the tightening pressure is relatively small. , B can be filled, and a substantially uniform sealing surface pressure can be generated around the opening holes H, Hs.
[0046]
Further, since the elastic layers 14, 24, 34 are covered with the coating layers 15, 25, 35 and confined, it is possible to prevent the elastic layers 14, 24, 34 from creeping or flowing, and to provide a high sealing for a long period of time. Performance can be maintained.
[0047]
That is, the elastic layers 14, 24, and 34 absorb the steps and roughness so that they can be sealed well, and the elastic layers 14, 24, and 34, which are the cushioning material, are coated with the relatively hard coating layers 15, 24. Since protection is performed by 25 and 35, the flow and creep of the elastic layers 14, 24 and 34 can be prevented.
[0048]
Then, as shown in FIGS. 5 to 7, by disposing the position holding members 27 on both sides of the elastic layer 24, the deformation of the elastic layer 24 in the plane direction of the gasket B can be prevented by the position holding members 27. Thus, the flow of the elastic layer 24 can be more effectively prevented. In addition, since the elastic layer 24 can be formed to be thick, the elastic layer 24 is more easily elastically deformed.
[0049]
Further, as shown in FIG. 8, by forming the elastic layer 24C on the groove 28C provided in the component plate 30C, the thickness of the elastic layer 24C can be further increased, and the amount of deformation can be increased. The sealing performance can be improved.
[0050]
When the elastic layers 14, 24, 34 are formed on the constituent plates 10, 20, 30 by printing, the elastic layers 14, 24, 34 having a complicated shape can be easily formed, and the layer thickness is changed by multiple printing. Therefore, it is easy to form the elastic layers 14, 24, 34 having an appropriate thickness according to the respective portions of the gaskets A, B.
[0051]
【The invention's effect】
As described above, according to the gasket of the present invention, the flexible elastic layer wrapped in the film layer can be deformed and has elasticity even at a portion where the tightening pressure is relatively small. When the member holding the gasket is tightened, the elastic layer deforms and can fill the gap between the member and the gasket, and a substantially uniform sealing surface pressure is generated around the opening hole to be sealed, which is favorable. A good sealing state can be ensured.
In addition, since the elastic layer is covered with the coating layer and is confined in the inside thereof, it is possible to prevent creep and flow from occurring.
[0052]
In addition, since the elastic layer exerts a sealing effect and the coating layer protects this elastic layer, the material of the elastic layer can be selected without considering problems such as creep and flow, and the range of usable materials can be expanded. be able to. At the same time, since the dimensional accuracy of the elastic layer can be made coarse, the production becomes easy and the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view of a cylinder head gasket showing a first embodiment according to the present invention.
FIG. 2 is a partial perspective view including a cross section of a portion X of the gasket of FIG.
FIG. 3 is a partial perspective view including a cross section of a portion X of the gasket of FIG. 1, showing a configuration in which an elastic layer is provided in a concave portion.
FIG. 4 is a plan view of a gasket showing a second embodiment according to the present invention.
5 is a partial perspective view including a cross section taken along line YY of the gasket of FIG. 4, showing a configuration in which a position holding member is provided by folding back a component plate.
6 is a partial perspective view including a cross section taken along the line YY of the gasket of FIG. 4, showing a configuration in which a position holding member for a strip is provided.
7 is a partial perspective view including a cross section taken along the line YY of the gasket of FIG. 4, showing a configuration in which a position holding member for a strip having a bead is provided.
8 is a partial perspective view including a cross section taken along the line YY of the gasket of FIG. 4, showing a configuration in which an elastic layer is provided on a groove formed in a component plate.
FIG. 9 is a cross-sectional view of a seal zone of a gasket, and (a) to (d) show examples in which a constituent plate and the like are deformed.
[Explanation of symbols]
A, B Gaskets 10, 10A, 20, 20A, 20B, 20C Component plates H, Hw, Ho, Hp, Hs Opening holes 14, 14A, 24, 24A, 24B, 24C Elastic layers 15, 15A, 25, 25A, 25B , 25C Coating layer 27, 27A, 27B Position holding member 28C Groove

Claims (2)

Surrounds the opening hole H formed in the gasket configuration plate 20, to form a band-like elastic layer 24 on the formation plate 20, the elastic layer 24 together with peripheral structure plate 20, harder than the elastic layer 24 in coated gasket with a coating layer 25 of synthetic resin material, the elastic layer 24 is NBR rubber, fluorine rubber, a rubber-based material such as silicone rubber, also the covering layer 25, epoxy resin, silicone resin, fluorine resin The constituent plate 20 is formed by folding both ends to one side to form a gap between both ends, and the both ends are used as a position holding member 20a. the elastic layer 24 disposed so as to protrude from the surface of the position maintaining member 20a, further characterized in that a laminate of cover layer 25 covers the surface of the position holding member 20a and the elastic layer 24 Gasquet Door. Band-shaped elastic layers 24A and 24B are formed around the opening holes H provided in the gasket constituting plates 20A and 20B, and the elastic layers 24A and 24B are hardened together with the surroundings, and the synthetic resin material is harder than the elastic layers 24A and 24B. In the gasket covered with the coating layers 25A and 25B, the elastic layers 24A and 24B are made of a rubber-based material such as NBR rubber, fluoro rubber, or silicone rubber, and the coating layers 25A and 25B are made of epoxy resin or silicone resin. , A soft synthetic resin material such as a fluororesin is used, and position holding members 27A and 27B made of separate strips are arranged on the constituent plates 20A and 20B of the gasket, and the position holding members 27A and 27B are formed. The elastic layers 24A, 24B are arranged so as to protrude from the surfaces of the position holding members 27A, 27B in the gap formed by the opposite ends of Elastic layer 24A, 24B and the position retaining member 27A, the gasket being characterized in that the coating layer 25A covering the surface of 27B, and 25B are stacked.

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