JP2005155713A - Metallic gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic gasket capable of ensuring stable sealing performance even when a combustion chamber hole and a liquid hole approach mutually due to enlargement of diameter of the combustion chamber hole in accordance with enlargement of diameter of a bore hole. <P>SOLUTION: This metallic gasket is constituted in such a way that thickness increasing parts 21 formed in end parts of each combustion chamber hole 3, respectively, a seal line SL1 set so as to surround each combustion chamber hole 3, and a bead BD for sealing between join faces along the seal line SL1 are formed on at least a base 2 using a thin-walled metallic plate in which the liquid hole 4 and a plurality of combustion chamber holes 3 are opened as the base 2. The bead BD is composed of a metallic bead 8 and a rubber bead 9. When the liquid hole arranged close to between adjacent combustion chamber holes 3 among the liquid holes 4 is called as the close liquid hole 4A, a part of the seal line SL1 is set as a liquid hole seal line SL1a by surrounding the whole periphery of a peripheral fringe of the close liquid hole 4A. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention, for example, is inserted between the opposed joint surfaces of a cylinder block and a cylinder head constituting an internal combustion engine used in motorcycles, automobiles, industrial machines, outboard motors, etc., and seals between the joint surfaces. In particular, the present invention relates to a metal gasket that can be suitably used for a cylinder head or the like in which the space between adjacent bore holes is extremely narrow.

A metal gasket having a thin metal plate as a substrate is used for, for example, a cylinder head for an internal combustion engine such as an engine. In such a metal gasket, the combustion chamber hole corresponding to the bore hole and the liquid hole corresponding to the cooling liquid hole are opened on the substrate, and a part of the liquid holes are adjacent to the combustion chamber hole. Some are placed close together.
In recent years, the diameter of the bore hole is sometimes increased as much as possible in order to increase the displacement without changing the basic design of the engine. When the diameter of the bore hole is increased, the distance between adjacent bore holes becomes narrower accordingly. In order to cool the space between such narrow bore holes effectively, it is desired to secure as large a coolant hole as possible. It is also desirable to increase the cooling effect by bringing the coolant holes as close as possible between the bore holes. Therefore, the coolant hole is designed to be as close as possible to both sides between the bore holes while making the opening diameter as large as possible.

The inventor of the present application has developed a metal gasket described in Patent Document 1, for example, as a metal gasket that can be used for such applications.
For example, as shown in FIG. 15, the metal gasket is set so as to surround the thickened portion 210 and the thickened portion 210 formed by folding the side end portion 300 a of the combustion chamber hole 300 or by using a thickened plate. A bead is formed along the seal line SL101. The thickened portion 210 and the bead BD seal the combustion gas.

For example, as shown in FIG. 16, the bead BD is formed along the seal line SL <b> 101 by a metal bead 80 formed by molding the substrate 200 and rubber beads 90 fixed to both the front and back surfaces of the metal bead 80. . In the example of the figure, the metal bead 80 is formed of a convex full bead. The rubber bead 90 is formed of an elastic sealing material that is fixed to the bent side and the bent back side of the metal bead 80 and compressively deforms in the plate thickness direction as the metal bead 80 is deformed. Usually, the elastic sealing material fixed to the front and back of the substrate is separately molded on the bent side and the bent back side to form rubber beads.
Japanese Patent Application No. 2002-102437

Here, in the metal gasket used in the engine having a narrow gap between the bore holes as described above, there is almost no space for forming a bead between the adjacent combustion chamber holes 300 as shown in a Z portion of FIG. That is, since the space between the adjacent combustion chamber holes 300 is narrow, it is difficult to secure a space necessary for forming the bead. Therefore, as shown in the figure, the seal lines SL101 between adjacent combustion chamber holes 300 are connected and set to form a bead BD.
However, in such a seal line structure, a rubber bead between adjacent combustion chamber holes is connected to a substantially V shape, for example, as shown as Y part in FIG. There is a tendency that the fixed state of becomes unstable.

  In addition, a bead surrounding the liquid hole may be formed around the liquid hole, and among these liquid holes, the cooling liquid hole arranged as large and close as possible on both sides between the bore holes is provided. Liquid holes formed at corresponding positions, for example, liquid holes 400A (hereinafter referred to as “proximity liquid holes”) disposed close to adjacent combustion chamber holes 300 as shown in FIG. When the space between the chamber holes 300 is narrow, a position where a bead is to be formed around the proximity liquid hole 400 </ b> A is closer to the thickened portion 210. Therefore, it is still difficult to secure a space necessary for molding the bead around the adjacent liquid hole.

Therefore, even if a bead that directly surrounds the surrounding liquid hole is formed, the fixed area (width) of the rubber beads fixed to the front and back of the substrate is a full bead formed with sufficient space secured. Less than Therefore, the adhesion strength of the rubber beads around the adjacent liquid holes is not always sufficient.
This leads to an acute angle between adjacent combustion chamber holes due to, for example, vibration during engine operation or displacement of the joint surfaces caused by differences in thermal expansion due to differences in material between the cylinder head and cylinder block. There is a possibility that the rubber beads in the portion (for example, Y portion in FIG. 15) or the rubber beads around the proximity liquid hole may be peeled off from the substrate.

Also, depending on the structure of the engine, the tightening conditions between the bore holes are stricter than other parts, and the influence of heat is also great. Therefore, especially when the gap between the bore holes is extremely narrow, there is a possibility that gas may blow out from the portion between the combustion chamber holes of the metal gasket, for example, when operating at a high load after stopping the engine. There is still room for improvement.
The present invention has been made paying attention to such a problem. For example, even when the combustion chamber hole and the liquid hole are brought close to each other by enlarging the combustion chamber hole diameter accompanying the enlargement of the bore hole, the present invention is long. It is an object of the present invention to provide a metal gasket that can stably ensure sealing performance over a period of time.

  In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention is a metal gasket interposed between joint surfaces facing each other between a cylinder block and a cylinder head constituting an internal combustion engine, wherein the joint surface is A thin metal plate having at least a liquid hole corresponding to a cooling liquid hole opened in a plurality of holes and a plurality of combustion chamber holes corresponding to a plurality of bore holes opened in the joint surface is used as a substrate. A thickened portion formed on the entire circumference of each end of each chamber hole, and a bead that deforms in the plate thickness direction of the substrate along a seal line set to surround the combustion chamber hole and seals between the joint surfaces And at least the substrate, and the bead is fixed to the bent side and the bent back side of the metal bead by bending the substrate toward one side in the plate thickness direction. Plate with deformation A rubber bead formed of an elastic sealing material that compressively deforms in a direction and has a height of a molding dimension on the bent side surface higher than that of the thickened portion, and is adjacent to the liquid hole. When the liquid holes arranged close to each other between the matching combustion chamber holes are referred to as adjacent liquid holes, a part of the seal line constitutes a liquid hole seal line surrounding the entire periphery of the adjacent liquid hole, and the liquid A feature is that a bead composed of a combination of the metal bead and the rubber bead is formed along a hole seal line.

According to the first aspect of the present invention, the bead surrounding the outer periphery of the thickened portion of the combustion chamber hole is merged with and integrated with the bead surrounding the entire peripheral edge of the adjacent liquid hole. Therefore, the adhesion strength can be complemented by the bead around the combustion chamber hole and the bead around the adjacent liquid hole. This increases the fixing strength of the entire bead and can compensate for the lack of strength around the adjacent liquid hole with a narrow bead width.
Here, it is difficult to sufficiently secure even the half bead width in the metal beads constituting the liquid hole seal line set around the adjacent liquid holes. Therefore, in such a case, it is preferable to employ a metal bead having a highly effective form with as little space as possible.

That is, the invention described in claim 2 is the metal gasket according to claim 1, wherein the metal bead formed in the liquid hole seal line is configured such that the substrate at the inner peripheral portion of the adjacent liquid hole is placed on the plate. It is characterized by being formed by bending rising obliquely toward the one side in the thickness direction.
According to the second aspect of the present invention, a metal bead shape having only a rising shape, that is, a “quarter bead” is formed along the liquid hole seal line, and rubber beads are respectively formed on both sides of the quarter bead. Thereby, even when the space for forming the bead is small, it is possible to obtain an effective metal bead for improving the sealing performance by effectively utilizing the space.

  The invention described in claim 3 is the metal gasket according to claim 1 or 2, wherein the elasticity fixed to the bent side and the bent back side constituting the rubber bead formed in the liquid hole seal line. The sealing material is connected and integrated with an elastic sealing material that adheres to the inner peripheral surface of the adjacent liquid hole, and the inner diameter dimension of the elastic sealing material that is applied to the inner peripheral surface of the hole is defined on the joint surface. It is characterized by being approximately the same size as the inner diameter of the open coolant hole.

  According to the third aspect of the present invention, the inner diameter of the adjacent liquid hole on the substrate is made slightly larger than the inner diameter dimension of the cooling liquid hole opened on the joint surface to be inserted. Then, the inner diameter after molding the elastic sealing material is formed to be approximately the same as the inner diameter of the coolant hole opening in the joint surface, that is, the regular inner diameter. As a result, the elastic sealing material can be connected to the front and back of the substrate by a width that increases the inner diameter of the substrate to form an edge mold. Therefore, the adhesion strength of the rubber beads around the adjacent liquid holes can be further increased. Therefore, it is possible to more suitably compensate for the insufficient strength around the adjacent liquid hole having a narrow bead width.

  The invention described in claim 4 is the metal gasket according to any one of claims 1 to 3, wherein the metal bead formed in the liquid hole seal line is arranged in a circumferential direction of the metal bead. It is characterized in that at least one notch is formed as a liquid hole notch in the direction along the direction, and the elastic sealing material on the bent side and the bent back side is connected and integrally formed through the liquid hole notch. Yes.

According to the invention described in claim 4, since the elastic sealing material on the front and back of the substrate can be connected to each other by the liquid hole notch, the insufficient strength of the rubber bead around the adjacent liquid hole having a narrow bead width can be compensated more suitably. be able to.
The invention described in claim 5 is the metal gasket according to any one of claims 1 to 4, wherein the thickened portion formed around the combustion chamber hole has an outer peripheral surface of the thickened portion. A portion along the peripheral edge of the adjacent liquid hole is cut out to form a thickened portion cutout portion, and a portion removed by the thickened portion cutout portion is formed along the liquid hole seal line. It is characterized by molding a part of the bead.

According to the fifth aspect of the present invention, by providing the thickened portion notch, it is possible to bring the range where the metal bead and the rubber bead can be formed around the adjacent liquid hole closer to the bore hole. it can. Therefore, it is possible to deal with a wider range as a metal gasket that can be provided to an internal combustion engine in which the coolant holes on the joint surface are located as close as possible between the bore holes.
Moreover, the invention described in claim 6 is the metal gasket according to any one of claims 1 to 5, wherein the adjacent combustion chamber holes and the side of the bead between the adjacent combustion chamber holes. In this range, a shim plate is interposed between the thickened portion provided at the end portion of the adjacent combustion chamber hole and the substrate.

  According to the sixth aspect of the present invention, the shim plate having a thickness smaller than that of the substrate is interposed, particularly within a strict range of sealing conditions. Thereby, the surface pressure between the bore holes can be set larger than the other portions. For this reason, for example, the engine can be operated to achieve a preferable sealing condition equal to or equal to or higher than that of other seal portions even after familiarity with the use. In addition, this shim plate can be expected to supplement the strength between extremely narrow bore holes.

  According to the present invention, there is provided a metal gasket capable of ensuring stable sealing performance even when the combustion chamber hole and the liquid hole are close to each other, for example, due to the expansion of the combustion chamber hole diameter accompanying the increase in the bore hole diameter. Can do.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate.
FIG. 1 is a main part plan view showing a metal gasket according to the present embodiment. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is a cross-sectional view taken along line BB in FIG. 1, and FIG. 4 is a cross-sectional view taken along line CC in FIG.
First, the structure of the metal gasket of this embodiment is demonstrated.
The metal gasket of the present embodiment is an example of a gasket that is interposed (inserted) between the joint surfaces of the cylinder head and the cylinder block of the internal combustion engine. Examples of the metal gasket substrate include a thin stainless steel plate, a mild steel plate, and an aluminum plate. In this embodiment, a mild steel plate is used to provide an inexpensive gasket. As will be described later, according to the metal gasket of the present embodiment, sufficient sealing performance can be ensured even when a substrate made of a thin metal plate with low rigidity such as a mild steel plate is used.

As shown in FIG. 1, combustion chamber holes 3, liquid holes 4, bolt holes 5, and oil holes 10 are opened in the substrate 2 of the metal gasket 1.
A plurality of combustion chamber holes 3 are formed in a substantially central portion of the substrate 2 so as to be greatly opened in a row in the longitudinal direction, and correspond to bore holes that open to the joint surface of the internal combustion engine and cause a plurality of combustion gases to explode. Each is formed at a position.
A plurality of liquid holes 4 are opened along the outer periphery of the combustion chamber hole 3 at positions corresponding to the cooling liquid holes opened in the joint surface. Of the liquid holes 4 that are open, a liquid hole 4 </ b> A between adjacent bore holes (hereinafter, this liquid hole is referred to as “proximity liquid hole”) is disposed close to the combustion chamber hole 2. Yes. In the figure, as the adjacent liquid hole 4A, two liquid holes that are opened in a circle are arranged between adjacent combustion chamber holes.

  Each bolt hole 5 is formed corresponding to a position through which a bolt for fastening and fixing the metal gasket 1 inserted between the cylinder head, the cylinder block, and the joint surface thereof is inserted. The oil hole 10 is opened corresponding to a predetermined position necessary for passing the lubricating oil. In addition, in the same figure, illustration of the right side of a longitudinal direction is abbreviate | omitted, However, The structure is the same also about each said hole opened to the part which abbreviate | omitted illustration.

  In the metal gasket 1, the opening end portions 3a of the plurality of combustion chamber holes 3 are folded back upward (in the example of FIG. Is formed. That is, a plate thickness difference is provided with respect to other seal portions to form a thickened portion. As a result, the first thickened portion 21 is designed so that the surface pressure is higher than that of other seal portions in a state where the first thickened portion 21 is attached between the joining surfaces, and the combustion gas having the highest seal pressure is sufficiently generated. Can be sealed.

Further, since the metal gasket 1 is for a multi-cylinder, that is, the bolt axial force of tightening is large and the distance from the combustion chamber hole 3 to the outer peripheral end is large, a part of the outer peripheral side end of the substrate 2 The second thickened portion 22 is provided by folding back part of the substrate. As a result, even when the bolt is tightened by a large axial force, it is possible to cope with it.
In the metal gasket 1, a plurality of seal lines SL1 to SL3 are respectively set on the substrate 2 as seal lines.

The first seal line SL1 circulates the entire plurality of combustion chamber holes 3 along the outer periphery of the first thickened portion 21 of the plurality of combustion chamber holes 3 opened side by side in the longitudinal direction, and one of the first seal lines SL1. The part is set so as to surround the entire circumference of the peripheral water hole 4A, and is set integrally with an endless ring.
The second seal line SL2 includes the oil hole 10 and the bolt hole 5A adjacent to the oil hole 10 out of the holes such as the liquid hole 4, the bolt hole 5, and the oil hole 10 that open to the outer periphery of the first seal line SL1. Except for this, it is set along the entire outer edge of the substrate 2 so as to surround the liquid hole 4. The seals of the liquid holes 4 other than the adjacent liquid holes 4A are provided with seal lines so as to surround the plurality of liquid holes 4 by the first seal line SL1 and the second seal line SL2 due to space and the like. Yes.

The third seal line SL3 is set so as to surround the oil hole 10, the bolt hole 5 </ b> A adjacent to the oil hole 10, and each bolt hole 5. Of the seal lines, the seal line portions that overlap because they are arranged in the vicinity and in parallel are shared, that is, integrated into one seal line.
Next, the configuration of the bead BD formed along all the seal lines SL1 to SL3 will be described.
The bead BD has a configuration in which metal beads 6 and 8 and rubber beads 7 and 9 are combined as shown in FIGS.

  Specifically, the metal beads 6 and 8 are full beads formed by bending the substrate 2 so as to protrude only on one surface side (upper side) of the substrate 2. The bead height is set to be higher than that of the first thickened portion 21, and a necessary sealing pressure can be generated by elastic deformation in the plate thickness direction. The rubber beads 7 and 9 are elastic sealing materials 7a, 7b, 9a and 9b fixed to the surface of the substrate 2 which is the bent side (convex portion side) of the metal beads 6 and 8, and the convex portions of the metal beads 6 and 8. It is comprised from the elastic sealing materials 7c and 9c with which it filled in the recessed part located in the bending back side. As the elastic sealing materials 7a, 7b, 7c, 9a, 9b, 9c, a material having corrosion resistance and elasticity, such as a rubber material such as fluorine rubber, NBR, silicon rubber, or a resin material can be preferably used. . The elastic sealing members 7a to 7c and 9a to 9c constituting the rubber beads 7 and 9 are fixed and filled on the surface of the substrate 2 on the convex side and the concave side of the metal beads 6 and 8, for example, by molding. Are molded. As a forming method, for example, a molding material passage hole (not shown) may be formed in each of the metal beads 6 and 8 so that the convex portion side and the concave portion side can be simultaneously formed.

  As shown in FIGS. 2 to 3, the shape of the rubber beads formed by molding or the like is such that the elastic sealing materials 7a, 7b, 9a, 9b fixed to the convex portions of the metal beads 6, 8 are at least metallic. The beads 6 and 8 are fixed to the surface of the substrate 2 so as to cover both sides in the width direction. The heights of the elastic sealing materials 7a, 7b, 9a, 9b fixed to the convex portions of the metal beads 6, 8 are the same as or substantially the same as the convex portions of the metal beads 6, 8, respectively. The upper surface is formed substantially parallel to the flat surface of the substrate 2. The height of the elastic sealing materials 7a, 7b, 9a, 9b may be set slightly higher than the height of the convex portions of the metal beads 6, 8. However, it is necessary that the amount of compressive deformation regulated by the height of the first thickened portion 21 be suppressed to 35% or less (the amount of compressive deformation not buckling, which is known in advance by the material). On the other hand, the filling amount of the elastic sealing materials 7c and 9c filled in the recesses of the metal beads 6 and 8 is substantially the same as the volume in the recesses and is substantially flush with the flat surface of the substrate 2. .

Next, the configuration of the peripheral edge of the adjacent liquid hole 4A surrounded by a part of the first seal line SL1 described above will be described in more detail.
As shown in FIG. 1, the seal line close to the proximity liquid hole 4A in the first seal line SL1 is set as a liquid hole seal line SL1a surrounding the peripheral edge of the proximity liquid hole 4A. That is, the bead BD of the first seal line SL1 disposed on the outer periphery of the first thickened portion 21 that is the thickened portion around the combustion chamber hole is merged with the liquid hole seal line SL1a of the adjacent liquid hole 4A to be integrated. By doing so, it is set as a seal line that includes the outer periphery of the first thickened portion 21 around the combustion chamber hole 3 and the vicinity of the adjacent liquid hole 4A.

  As shown in FIG. 4, the rubber beads 17 formed on the liquid hole seal line SL1a set around the peripheral edge of the proximity liquid hole 4A are elastic seal members 17a fixed to the bent side and the bent back side of the metal beads 13. 17b is applied to the inner peripheral surface of the adjacent liquid hole 4A. That is, the elastic sealing material 17c for adhering the elastic sealing materials 17a and 17b fixed to the bent side and the bent back side constituting the rubber bead 17 formed in the liquid hole sealing line SL1a to the inner peripheral surface of the adjacent liquid hole 4A. It is connected and united with. In other words, the elastic sealing material is connected to each other via the elastic sealing material 17c attached to the inner peripheral surface of the adjacent liquid hole 4A and arranged up to the opening end of the adjacent liquid hole 4A.

  At this time, if the elastic sealing material 17c formed on the inner diameter surface of the proximity liquid hole 4A is formed with the inner diameter of the substrate 2 of the proximity liquid hole 4A as it is, the inner diameter of the proximity liquid hole 4A corresponding to the film thickness T of the elastic sealing material 17c. The dimension Dw is reduced. Therefore, the hole diameter is set large in advance so that the inner diameter of the liquid hole 4 obtained by subtracting the thickness T of the elastic sealing material 17c is equal to the diameter of the cooling liquid hole of the cylinder head or the like, and the flow path of the cooling water is It is configured to prevent local narrowing at the gasket position.

  In other words, the hole diameter of the substrate 2 of the proximity liquid hole 4A is formed to be slightly larger than the normal dimension, and the metal beads around the enlarged proximity liquid hole 4A are formed as the quarter beads 13. Specifically, this metal bead is formed by bending the substrate 2 in the inner peripheral portion of the adjacent liquid hole 4A obliquely toward one side in the plate thickness direction, as shown in FIG. Therefore, the metal bead shape consisting only of the rising shape, that is, the quarter bead 13 is formed along the liquid hole seal line SL1a.

Furthermore, the inner diameter dimension Dw of the adjacent liquid hole 4A including the thickness T in the radial direction of the elastic sealing material 17c attached to the inner peripheral surface of the hole is opened on the joint surface where the metal gasket 1 is interposed. The inner diameter of the cooling liquid hole is substantially the same.
As shown in FIG. 5, the rubber beads 17 of the proximity liquid holes 4 </ b> A are formed by notching the substrate 2 on the inner peripheral surface side of the proximity liquid holes 4 </ b> A in the direction along the circumferential direction of the quarter beads 13. Part 15 is formed. Also, as shown in FIG. 4, the liquid hole cutout portion 15 is formed by connecting the elastic sealing materials 17a and 17b on the bent side and the bent back side to each other. Thereby, since the area of the part where the rubber beads 17 on the front and back of the substrate are connected to each other is further expanded, the fixing strength is further strengthened.

  Further, as shown in an enlarged view in FIG. 6, the thickened portion notch portion 16 is formed in the first thickened portion 21 formed around the combustion chamber hole 3. The thickened portion cutout portion 16 is formed by cutting out a portion on the outer peripheral surface side of the first thickened portion 21 and along the peripheral edge of the proximity liquid hole 4A. And the bead formed in the part removed by this thickening part notch part 16 along liquid hole seal line SL1a set as a part of 1st seal line SL1 in the peripheral periphery of the proximity | contact liquid hole 4A Part of is molded.

  Further, as shown in FIG. 7, a shim plate 14 is attached between the adjacent combustion chamber holes 3. Specifically, the shim plate 14 is formed of a thin metal plate that is thinner than the substrate 2. As shown in the figure, the outer shape of the shim plate 14 is such that the adjacent combustion chamber holes of the first seal line SL1 set so as to surround the combustion chamber holes 3 between the adjacent combustion chamber holes 3. It is substantially the same shape or slightly smaller than the shape created by the contour in the range between the three. The shim plate 14 is interposed between the first thickened portion 21 and the substrate 2 provided at the end portion of the combustion chamber hole 3 as shown in a cross-sectional view in FIG.

Next, functions and effects of the metal gasket will be described.
When the metal gasket 1 having the above-described configuration is interposed between the opposing joint surfaces of the cylinder block and the cylinder head and tightened with fastening bolts, the elastic seal members 7a, 7b, 9a, 9b and the elastic beads 7 and 9 are formed. The sealing materials 7c, 9c cooperate with the metal beads 6, 8 and compressively deform in the plate thickness direction. At the end of tightening, the first thickened portion 21 of the thickest substrate 2 and the other thickened portions 21 Due to the plate thickness difference with the portion, the surface pressure is concentrated most in the first thickened portion 21 and the maximum load is applied.

  Thus, a triple seal is mainly performed by the maximum surface pressure of the first thickened portion 21 and the elastic repulsive force of each bead BD (metal beads 6, 8 and rubber beads 7, 9), and the first thickened portion 21 Due to the stopper effect of the metal beads 6 and 8, the elastic sealing members 7a to 7c and 9a to 9c fixed and filled on the convex side and the concave side of the metal beads 6 are prevented from being bent completely. Due to this stopper effect, the elastic seal members 7a to 7c and 9a to 9c fixed and filled on the convex side and the concave side of the metal beads 6 and 8 are prevented from being bent completely. Further, the surroundings of each liquid hole 4 and the adjacent liquid hole 4A are also surrounded by the bead BD having the above-described configuration, thereby preventing the cooling water from moving to the outside of the bead BD.

  Further, the elastic sealing materials 7a, 7b, 9a, 9b on the convex side of the metal beads 6, 8 and the elastic sealing materials 7c, 9c on the concave side both have a large sealing area, that is, a surface seal and contact with the joint surface. Since the portion to be made is rubber or rubber-like, it is possible to satisfactorily seal the wrinkles on the joint surface and the nest hole generated during casting with a low surface pressure, and the elastic sealing materials 7a to 7c and 9a to 9c are Since it is a sealing material made of an elastic material (especially rubber), the gasket coefficient is low, and as a result, a limited axial load can be used effectively in places with poor conditions, and the overall load can be reduced.

  That is, the repulsive force of the metal beads 6 and 8 and the elasticity of the elastic sealing materials 7a to 7c and 9a to 9c fixed and filled on the convex side (bending side) and the concave side (bending back side) of the metal beads 6, 8 Since the necessary sealing pressure is obtained in synergy with the repulsive force, the hardness of the substrate 2 itself can be lowered, and the metal beads 6 and 8 of the substrate 2 are hardly damaged by fatigue. Furthermore, the vibration of the engine and the seal surface roughness can be absorbed, and the cooling water pressure and the oil pressure can be satisfactorily sealed with a small surface pressure.

Moreover, according to this metal gasket 1, since the board | substrate which consists of thin metal plates, such as stainless steel and mild steel, is employ | adopted as a metal gasket, it is easy to ensure the thickness accuracy of a metal gasket and to manage this. . In addition, since a metal plate with low hardness is employed, fatigue failure at a bent portion (bent R portion) can be prevented even when a repeated load is applied, for example.
By the way, recent engines have been reduced in size, weight, and performance, and further, due to demands for energy saving, etc., in order to burn lean fuel, the combustion efficiency is improved by direct fuel injection, etc. High pressure is progressing. In particular, in the reduction in size and weight, the gap between the bore holes of the cylinder tends to be rapidly narrowed with the spread of the metal gasket. In recent development, for example, the gap between the bore holes is challenged to 4 mm or less.

  However, the narrower the gap between the bore holes, the more difficult the cooling between the bore holes becomes. Therefore, how to make the coolant holes close to the bore holes is an important issue. Also, especially between adjacent bore holes, there is a risk of high temperature and high pressure combustion gas, vibration due to explosion, thermal expansion difference due to differences in engine materials, etc., which may cause displacement of the gasket seal surface. In order to raise the room temperature and seal higher pressure gas, the structure needs to be sufficiently considered.

  Therefore, in the metal gasket 1 according to the present invention, the bead surrounding the outer periphery of the first thickened portion 21 of the combustion chamber hole 3 is merged with the bead of the adjacent liquid hole 4A and integrated. Therefore, the adhesion strength can be complemented by the bead around the combustion chamber hole 3 and the bead around the adjacent liquid hole 4A. As a result, the fixing strength of the entire bead is increased, and insufficient strength around the adjacent liquid hole 4A having a narrow bead width can be compensated.

Here, it is difficult to secure a sufficient bead width in the metal beads constituting the liquid hole seal line SL1a set around the adjacent liquid hole 4A. Therefore, a metal bead having a shape that is as effective as possible, that is, a quarter bead 13 is adopted in as little space as possible.
In particular, the metal bead (quarter bead 13) of the proximity liquid hole 4A is formed by bending the substrate 2 on the inner peripheral portion of the proximity liquid hole 4A obliquely toward one side in the plate thickness direction. That is, the metal bead shape including only the rising shape, that is, the quarter bead 13 is formed along the liquid hole seal line. Thereby, when there is little space which forms a bead, it can be set as an effective metal bead in improving sealing performance by utilizing space effectively.

  Further, the inner diameter of the adjacent liquid hole 4 </ b> A on the substrate 2 is slightly larger than the inner diameter dimension of the cooling liquid hole opened in the joint surface to be inserted. Then, the inner diameter dimension Dw after molding the elastic sealing material is formed to be approximately the same as the inner diameter dimension of the coolant hole opening in the joint surface, that is, the regular inner diameter dimension. Thereby, the rubber beads 17 (elastic seal material) can be connected to the front and back of the substrate by the width (film thickness T) of which the inner diameter of the substrate 2 is increased to form an edge mold. Therefore, the adhesion strength of the rubber beads 17 around the proximity liquid hole 4A can be further increased. Therefore, insufficient strength around the adjacent liquid hole 4A having a narrow bead width can be more appropriately compensated.

Further, the rubber beads 17 (elastic seal material) on the front and back of the substrate are connected to each other by the liquid hole notch 15. Therefore, the insufficient strength of the rubber bead 17 around the adjacent liquid hole having a narrow bead width can be more preferably compensated.
Furthermore, by providing the thickened portion notch portion 16, the range in which the metal bead 13 and the rubber bead 17 can be formed around the proximity liquid hole 4A is brought closer to the combustion chamber holes 3, that is, between the bore holes. be able to. Therefore, it is possible to deal with a wider range as a metal gasket that can be provided to an internal combustion engine in which the coolant holes on the joint surface are located as close as possible between the bore holes.

  Furthermore, a shim plate 14 having a thickness smaller than that of the substrate 2 is interposed in a particularly severe range of sealing conditions. Thereby, the surface pressure between the combustion chamber holes 3, that is, between the bore holes can be set larger than that of the other portions. Therefore, even after the engine is operated and familiarized with the use, it is possible to obtain a preferable sealing condition equivalent to or equal to or higher than that of the other sealing portions. That is, the tightening surface pressure around the bore hole can be averaged, and the sealing efficiency of the combustion gas can be improved.

As described above, according to this metal gasket, even if the combustion chamber hole and the liquid hole (proximity liquid hole) are close to each other due to the increase in the combustion chamber hole diameter accompanying the increase in the bore hole diameter, The sealing performance of the elastic sealing material around the provided proximity liquid hole can be ensured stably for a long period of time.
The metal gasket of the present invention described above is not limited to the above embodiment, and can be appropriately changed without departing from the gist of the present invention.

For example, in the said embodiment, although the board | substrate 2 is formed from a mild steel plate, it is not limited to this, A stainless steel plate and other thin metal plates can be used conveniently.
Further, for example, in the above embodiment, the first thickened portion 21 is formed by folding the end portion of the substrate 2 on the combustion chamber hole 3 side, but instead, as shown in FIG. A shim plate 50 having substantially the same thickness as the substrate 2 may be attached to the end of the combustion chamber hole 3 of the substrate 2 by welding or the like to form the first thickened portion 21. Alternatively, as shown in FIG. 10 as a modified example, the end of the combustion chamber hole 3 of the substrate 2 is sandwiched between grommets 51, or as shown in FIG. 11 as a modified example, the end of the combustion chamber hole 3 of the substrate 2 The first thickened portion 21 may be sandwiched by the grommet 51 via the elastic plate 53, and further, as shown as a modified example in FIG. 12, a metal bead is formed at the end of the combustion chamber hole 3 of the substrate 2. The first thickened portion 21 may be formed by attaching a shim plate 54 formed with a welded plate or the like.

  Further, for example, in the above embodiment, the metal beads of each bead along the first seal line SL1, the second seal line SL2, and the SL3 on the outer peripheral side of the combustion chamber hole 3 other than the metal beads around the proximity liquid hole 4A are full beads. However, the present invention is not limited to this. For example, instead of the metal beads 6 and 8 made of full beads, metal beads 54 and 56 made of stepped half beads are used as substrates as shown in FIG. 2 may be formed by bending, and an elastic sealing material may be fixed and filled in the convex and concave portions of the metal beads 54 and 56. However, it is desirable to form the seal line with a full bead if the space for forming the bead is sufficiently secured.

  Further, for example, in the above-described embodiment, the convex metal beads 6 and 8 are provided around the first thickened portion 21 at the end of the combustion chamber hole 3, around the oil hole 10, the liquid hole 4, and the bolt hole 5 as necessary. For each of the convex metal beads 6, 8, the bead height and bead width are appropriately changed in accordance with the rigidity of the joint surface at the position where they abut each other. The sealing efficiency may be improved by equalizing the sealing pressure along the line. The bead height and bead width can be changed by making the width of the metal beads 6 and 8 wider or higher at locations where the surface pressure is weak and the surface pressure is weaker.

Furthermore, in the above embodiment, the upper surfaces of the elastic sealing materials 7a, 7b, 9a and 9b fixed to the convex side of the metal beads 6 and 8 are substantially parallel to the flat surface of the substrate 2. There is no need to do so, and various shapes can be adopted as long as they can cooperate with the metal beads 6 and 8 and be compressed and deformed in the thickness direction.
Moreover, in the said embodiment, although the elastic sealing materials 7c and 9c filled in the recessed part of the metal beads 6 and 8 are made substantially flush with the flat surface of the board | substrate 2, it cooperates with the metal beads 6 and 8. The elastic sealing materials 7c and 9c may be somewhat uneven with respect to the flat surface of the substrate 2 as long as they can be compressed and deformed in the thickness direction. For example, as shown in FIG. 14 as a modified example, the elastic seal members 7c and 9c filled in the concave portions of the metal beads 6 and 8 are provided with a recess 58 to facilitate the deformation of the elastic seal members 7c and 9c. Also good.

In the above-described embodiment, an example in which the planar shape of the proximity liquid hole 4A is circular has been described. However, the present invention is not limited to this. For example, an elliptical shape or a shape in which the corners of a triangle are rounded by an arc ( For example, even the conventional liquid hole 400A) shown in FIG. 15 has the effects of the present invention.
Further, in the above embodiment, the inner diameter of the proximity liquid hole 4A portion on the substrate 2 is increased, and the liquid hole notch 15 is provided, thereby connecting the elastic sealing materials 17a and 17b on the front and back of the substrate to each other to connect the rubber beads 17 to each other. However, the present invention is not limited to this, and even if one of the means is used to connect the elastic sealing materials on the front and back of the substrate to each other, the adhesion strength of the elastic sealing material is insufficient. Can be supplemented. However, in order to secure a more stable fixing strength, as in the present embodiment, the elastic sealing materials 17a and 17b are attached to the inner peripheral surface of the adjacent liquid hole 4A and connected to each other to connect the adjacent liquid holes 4A. It is desirable that the adhesive strength of the rubber beads 17 (elastic seal material) be further increased by arranging the elastic seal members 17a and 17b on the front and back sides of the substrate with the liquid hole notch 15 while arranging them up to the opening end.

It is a fragmentary top view explaining one Embodiment of the metal gasket which concerns on this invention. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is CC sectional drawing in FIG. It is a partial top view explaining the shape of the board | substrate around a proximity | contact liquid hole. It is the elements on larger scale explaining the structure around an adjacent liquid hole. It is the elements on larger scale explaining the state which interposed the shim board between the adjacent combustion chamber holes. It is DD sectional drawing in FIG. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is explanatory drawing of the modification of the metal gasket which concerns on this invention. It is a partial top view explaining an example of the conventional metal gasket. It is EE sectional drawing in FIG.

Explanation of symbols

SL1 1st seal line SL1a Liquid hole seal line SL2 2nd seal line SL3 3rd seal line BD Bead 1 Metal gasket 2 Substrate 3 Combustion chamber hole 4 Liquid hole 4A Proximity liquid hole 5 Bolt hole 10 Oil hole 6, 8 Metal bead 7 , 9 Rubber bead 13 Metal bead (of adjacent liquid hole) 14 Shim plate 15 Liquid hole notch 16 Thickened part notch 17 Rubber bead 21 (thickened liquid hole) First thickened part 22 Second thickened part

Claims (6)

In the metal gasket interposed between the joint surfaces facing the cylinder block and the cylinder head constituting the internal combustion engine,
A thin metal plate having at least a liquid hole corresponding to a cooling liquid hole opened in the joint surface and a plurality of combustion chamber holes corresponding to a plurality of bore holes opened in the joint surface is used as a substrate. ,
A thickened portion formed at the entire circumference of each end of each combustion chamber hole and a seal line set so as to surround the combustion chamber hole are deformed in the plate thickness direction of the substrate to seal between the joint surfaces. A bead to be formed on at least the substrate,
A metal bead obtained by bending the bead toward one side in the plate thickness direction, and a bead that is fixed to the bent side and the bent back side of the metal bead and elastically deformed in the plate thickness direction along with the deformation of the metal bead. A rubber bead formed from a sealing material and having a molding dimension height on the bent side surface higher than the height of the thickened portion;
Among the liquid holes, when a liquid hole arranged close to adjacent combustion chamber holes is called a proximity liquid hole, a part of the seal line is a liquid hole seal that surrounds the entire circumference of the adjacent liquid hole A metal gasket comprising a line and a bead composed of the metal bead and the rubber bead formed along the liquid hole seal line.   2. The metal bead formed in the liquid hole seal line is formed by bending the substrate at an inner peripheral portion of the adjacent liquid hole obliquely toward the one side in the plate thickness direction. Metal gasket as described in.   The elastic sealing material fixed to the bent side and the bent back side constituting the rubber bead formed in the liquid hole seal line is connected by an elastic seal material that adheres to the inner peripheral surface of the adjacent liquid hole. The inner diameter dimension of the elastic sealing material deposited on the inner peripheral surface of the hole is substantially the same as the inner diameter dimension of the cooling liquid hole opened in the joint surface. 2. The metal gasket according to 2.   The metal bead formed in the liquid hole seal line is formed with at least one notch in the direction along the circumferential direction of the metal bead as a liquid hole notch, and the bent side through the liquid hole notch The metal gasket according to any one of claims 1 to 3, wherein the elastic sealing material on the bent back side is connected and integrally formed. In the thickened part formed around the combustion chamber hole, a thickened part cutout part is formed by notching a part on the outer peripheral surface side of the thickened part and along the peripheral edge of the adjacent liquid hole,
The part of the bead formed along the liquid hole seal line is formed in a portion removed by the thickened portion notch portion, according to any one of claims 1 to 4. Metal gasket.   A shim plate is provided between the substrate and the thickened portion provided at the end of the adjacent combustion chamber hole in the range between the adjacent combustion chamber holes and the side of the bead between the adjacent combustion chamber holes. The metal gasket according to any one of claims 1 to 5, wherein the metal gasket is interposed.

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