JP4845833B2 - Metal gasket - Google Patents

Description

  The present invention relates to a metal gasket for sealing a joint surface when two structures are fastened, and more particularly to a metal gasket capable of sealing a joint surface between a cylinder head and a cylinder block of an internal combustion engine.

Conventionally, metal gaskets have been used in various technical fields, and one of them is a metal gasket for a cylinder head that seals a joint surface between a cylinder head and a cylinder block of an internal combustion engine. Some of the cylinder head metal gaskets have a grommet portion having a shape in which a metal plate is folded, and the grommet portion surrounds a combustion chamber hole.
In recent years, in order to increase the output and efficiency of an internal combustion engine, the combustion gas pressure in the combustion chamber hole for sealing tends to increase. For this reason, in order to ensure sealing performance, it is necessary to increase the clamping surface pressure of the joint surface between the cylinder head and the cylinder block. However, in this case, excessive clamping surface pressure may be applied locally. Otherwise, the cylinder head or cylinder block may be deformed or the metal gasket may be damaged. Therefore, the tightening surface at the joint surface between the cylinder head and the cylinder block has a tightening surface pressure that exhibits a sufficient gas sealing property and does not apply excessive tightening surface pressure locally. It is becoming increasingly important to adjust the pressure distribution.

In order to cope with this, for example, a coating layer having an appropriate thickness is attached to the metal thin plate portion adjacent to the grommet portion so that even if the predetermined tightening surface pressure distribution changes minutely Thus, it has been proposed to set the difference in tightening surface pressure between the grommet portion and the adjacent portion so as to coincide with the surface pressure difference in the required tightening surface pressure distribution (see, for example, Patent Document 1). ).
JP-A-11-315931

  With the gasket described in Patent Document 1, the tightening surface pressure distribution in the radial direction of the combustion chamber hole to be sealed can be adjusted, but cannot be adjusted in the circumferential direction of the combustion chamber hole. However, considering the case where a metal gasket is actually inserted between the cylinder head and the cylinder block and tightened, the tightening surface pressure applied to the grommet portion and the adjacent region is affected by the position of the fastening bolt and the cylinder head and cylinder block. Depending on the rigidity and the like, the distribution varies depending on the circumferential position of the combustion chamber hole. Therefore, with the gasket described in Patent Document 1, it is not possible to obtain an appropriate tightening surface pressure distribution over the entire circumference of the combustion chamber hole, and it is difficult to achieve an appropriate seal.

In order to cope with this, for example, it is conceivable to obtain a predetermined tightening surface pressure distribution by changing the thickness in the circumferential direction of the grommet portion.
However, since the change in thickness is very fine, the initial thickness adjustment requires an extremely precise thickness adjustment, and the tightening surface pressure distribution is likely to change due to environmental changes and fine deformations. Since variations tend to occur, the design is inferior in flexibility and robustness.

  Also, in the cylinder head assembly process, when the fastening bolts are tightened and the cylinder head is locally fastened to the cylinder block, it is difficult to maintain the parallelism of the joint surface between the cylinder head and the cylinder block. In the initial assembly, it is very difficult to obtain an appropriate tightening surface pressure distribution. Even if an appropriate tightening surface pressure distribution is obtained in the initial stage, the optimum tightening surface pressure distribution can be maintained due to changes over time in the dimension (thickness dimension) in the load direction due to the creep characteristics of the gasket. It is difficult. Therefore, it is difficult to obtain an optimal tightening surface pressure distribution during initial assembly, and it is difficult to stably maintain an optimal tightening surface pressure distribution over a long period of time.

  Therefore, the object of the present invention is to solve the above-mentioned problems, and to easily obtain the optimum tightening surface pressure distribution at the time of initial assembly, and to stably obtain the optimum tightening even after long-term use. The object is to provide a metal gasket capable of maintaining a surface pressure distribution.

In order to solve the above-mentioned problems, one embodiment of the metal gasket according to the present invention has a substantially flat main body provided with an opening, and a folded portion formed by folding a thin plate, and the folded portion. A grommet part surrounding the opening by the metal gasket,
The grommet portion is formed with a collar portion where the thin plate continuous from the folded portion overlaps the main body, and the width of the collar portion is not constant in the same grommet portion.

  The metal gasket according to the present invention can be applied to the sealing of the joint surface of any structure, but particularly to the sealing of the joint surface when fastening a cylinder head and a cylinder block of an internal combustion engine exposed to high temperature and high pressure. Is suitable. Among them, a diesel engine with a high compression ratio has a higher combustion gas pressure, so it can be said that it is more effective to use the metal gasket according to the present invention.

Here, the substantially flat main body includes a case where the main body has an uneven portion or a bent portion, and may be formed of one member or a plurality of members. In the case of a plurality of members, for example, a laminated structure made of different materials is conceivable, and a structure having a coating layer on the outside of the core material is also conceivable.
As the material of the main body excluding the coating layer, it is possible to use any metal material including stainless steel, carbon steel, aluminum, copper, and heat-resistant alloy, and use the most suitable material according to the operating pressure and operating temperature. be able to.
The coating layer can be coated with any organic or inorganic material such as rubber or fluororesin, or can be coated with metal powder such as molybdenum dioxide, aluminum or stainless steel. Further, the coating layer can be directly coated on the metal of the core material, or can be coated on a thin plate of the outer layer disposed outside the core material. When the coating layer is provided, the sealing property can be maintained even if some deformation occurs due to its elasticity. In addition, the opening provided in the main body can have an arbitrary cross-sectional shape including a circle and a rectangle.

The grommet portion can be formed integrally with the main body, or can be constituted by a member different from the main body, as will be described later. In the case of forming integrally with the main body, for example, a folded portion can be formed using an outer layer thin plate disposed outside the core material, and a grommet portion can be provided. Further, the inside of the folded portion can be hollow, or a core material can be provided inside as described later. Moreover, the collar part of a grommet part can also be provided in the both surfaces side of a main body, and can also be provided only in the single side | surface side.
In addition, as the material for the grommet, any metal material such as stainless steel, carbon steel, aluminum, copper, and heat-resistant alloy can be used as well as the main body, and it is optimal according to the operating pressure and operating temperature. Can be used. Further, similarly to the main body, a coating layer using any material can be provided.

The width of the collar portion that overlaps the main body indicates an “overlap margin” in which a thin plate continuous from the folded portion of the grommet portion overlaps the main body. When a tightening load is applied to the gasket, it is considered that the load is mainly received by a part of the folded portion of the grommet portion and the collar portion in the peripheral region of the opening. Therefore, when receiving the same tightening load, if the width of the collar part is wide, that is, if the overlap margin is large, the clamping surface pressure in this region will be small, and if the width of the collar part is narrow, that is, the overlap margin is small In this case, the tightening surface pressure in this region increases.
The width of the collar part can be changed locally, or the width of the collar part can be changed continuously. In addition, when the collar portion is provided on both sides of the main body, the width dimension of the collar portion can be changed in the same manner on both sides, or the width dimension of the collar portion can be changed in a different manner on each surface. You can also In this case, a mode in which the width dimension of the collar portion of one surface is changed and the width dimension of the collar portion of the other surface is not changed is also included.

In this embodiment, the width of the brim portion of the grommet portion is adjusted even if excessive tightening weight or low tightening weight that cannot maintain the sealing performance is applied depending on the position in the peripheral region of one opening. By doing so, it is possible to obtain an appropriate tightening surface pressure in the peripheral region of the opening.
In addition, since the temporal change in the tightening surface pressure distribution due to creep characteristics or the like is small, the gasket can be used for a long time in a stable state. Furthermore, since the sealing by surface contact can be performed by the collar portion of the grommet portion, the effective sealing area can be increased, and a gasket structure suitable for various sealing situations can be obtained. For example, even when the joint surfaces of the structures to be fastened are not parallel, it is easy to form an effective seal surface.

  In another embodiment of the metal gasket according to the present invention, the metal gasket is inserted between two structures, and the two structures are fastened by a fastening member to seal the joint surfaces of the two structures. In this case, the width of the collar portion is determined so as to form a predetermined tightening surface pressure distribution in a peripheral region of the opening based on the position of the fastening member and the rigidity of the structure. .

  When a gasket is inserted between two structures, the two structures are fastened with a fastening member, and the joint surface is sealed, the tightening load in the peripheral region of the opening depends on the position of the fastening member and the structure. Depending on the position, the value varies depending on the position.For example, the influence of the structure is analyzed structurally to obtain the optimum tightening surface pressure distribution in the surrounding area of the opening. Can be determined. In this case, computer analysis using a finite element method or the like is also an effective means.

  Another embodiment of the metal gasket according to the present invention is characterized in that a core member is provided inside the folded portion of the grommet portion.

  Here, as the core member, for example, a core member having a circular cross-sectional shape can be used, a core member having a rectangular cross-sectional shape can be used, or a core member having any other cross-sectional shape. Can be used. In addition, as the material of the core member, any metal material including tenless steel, carbon steel, aluminum, copper, and a heat-resistant alloy can be used.

  In this embodiment, since the core member is provided inside the folded portion, the tightening load can be more reliably received at the folded portion of the grommet. Further, when the core member has great elasticity, even if a relatively large deformation occurs, the sealing performance can be maintained.

  Another embodiment of the metal gasket according to the present invention is characterized in that the grommet portion is composed of a member different from the main body.

  In this embodiment, since the grommet portion is composed of a member different from the main body, the degree of freedom of material and shape is increased, and an optimum tightening surface pressure distribution is obtained under a wide range of conditions by combining the grommet portion and the main body. be able to. In addition, when the grommet part is composed of a member different from the main body, as a rule, it is possible to provide brim parts on both sides of the main body, so the width of the brim parts on both sides can be adjusted to make it more diverse and detailed. Adjustment of the tightening surface pressure can be realized.

  In another embodiment of the metal gasket according to the present invention, in the same grommet part, the thickness of the grommet part is not constant, and the opening part is formed by a combination of a width dimension of the collar part and a thickness dimension of the grommet part. A predetermined tightening surface pressure distribution is formed in the peripheral region of the.

In this embodiment, by changing not only the width dimension of the collar part but also the thickness dimension of the grommet part, a combination of the width dimension of the collar part and the thickness dimension of the grommet part, that is, the fastening surface at the folded part of the grommet part Since the pressure and the tightening surface pressure of the collar portion can be finely adjusted, the optimum tightening surface pressure distribution in the peripheral region of the opening can be obtained more effectively.
In another embodiment of the metal gasket according to the present invention, when the joint surface between the cylinder head and the cylinder block of an internal combustion engine having a plurality of cylinders is sealed, the collar of the metal gasket to be mounted for each cylinder. The shape of the part is different.

  In this embodiment, when used to seal the joint surface between the cylinder head and the cylinder block, the tightening load and the tightening surface pressure may be different for each cylinder. By using a metal gasket having a different shape of the collar portion, an optimum tightening pressure distribution can be obtained in the entire cylinder head and cylinder block.

As described above, in the gasket according to the present invention, by adjusting the width of the collar portion of the grommet portion, it is possible to easily obtain an appropriate tightening surface pressure in the peripheral region of the opening portion during initial assembly. In addition, since the temporal change in the tightening surface pressure distribution due to creep characteristics or the like is small, the gasket can be used for a long time in a stable state.
Furthermore, since the sealing by surface contact can be performed by the collar portion of the grommet portion, the effective sealing area can be increased, and a gasket structure suitable for various sealing situations can be obtained.

Embodiments of a metal gasket according to the present invention will be described below in detail with reference to the drawings. Here, in FIGS. 1-4, the top view which shows a part of metal gasket 2 in which the some opening part 6 was provided in FIGS. 1-4 (a), respectively is shown, and FIGS. 1-4 (b) ) And (c) are partial cross-sectional views seen from the direction of the arrows shown in FIGS. 1 and 2 show the shape of the grommet 8 attached to the opening 6 disposed at the end among the plurality of openings 6 provided in the metal gasket 2, and FIGS. Of the plurality of openings 6 provided in the metal gasket 2, the shape of the grommet 8 attached to the opening 6 arranged at an intermediate position (a position that is not the end) is shown. In the following description, the upper side is described as the upper side, the lower side is the lower side, the right side is the right side, and the left side is the left side.
In addition, the metal gasket 2 according to the present invention can be used for sealing the joint surfaces of all structures, and in particular, can exhibit high sealing performance even in a seal under an environment exposed to high temperature and high pressure. For example, the present invention can be applied to a seal of a joint surface between a cylinder head and a cylinder block of an internal combustion engine. In particular, in the case of a diesel engine having a high compression ratio, it is exposed to a higher pressure. It is particularly effective to use a metal gasket according to the above.

(Description of embodiment shown in FIG. 1)
First, an embodiment of a metal gasket according to the present invention will be described with reference to FIG.
<Description of overall metal gasket structure>
First, the overall structure of the metal gasket 2 provided with a plurality of openings 6 will be described with reference to FIG. The metal gasket 2 includes a substantially flat main body 4 and a grommet portion 8. The main body 4 is provided with a plurality of openings 6, and the grommet portions 8 are attached to the respective openings 6. This configuration is the same in the embodiments shown in FIGS. 1 to 4. As will be described later, the shape of the grommet portion 8, particularly the shape of the collar portion 8 b of the grommet portion 8 is different in each drawing. In principle, the other shapes are the same. In addition, as a cross-sectional shape of the opening part 6 provided in the main body 4, it can have arbitrary shapes including circular and a rectangle.

  In the present embodiment, the main body 4 and the grommet portion 8 are made of different members, and the grommet portion 8 is fitted into the main body 4 in the opening 6 to form one metal gasket 2. However, it is not restricted to this, The main body 4 and the grommet part 8 can also be integrally formed like embodiment shown in FIG. 6 mentioned later.

<Description of body 4>
The substantially flat main body 4 does not have to be completely flat, and includes a case where there are some uneven portions and bent portions. For example, a spring-like sealing mechanism can be formed by providing an uneven portion so as to surround the opening 6.
Moreover, the case where the main body 4 is comprised with one member is also considered, and the case where it is comprised with a some member is also considered. In the case of a plurality of members, for example, a stacked structure in which a plurality of different layers are stacked is conceivable, and a structure having a coating layer on the outside of the core material is also conceivable.
As the material constituting the main body 4 excluding the coating material, any metal material such as stainless steel, carbon steel, aluminum, copper, and a heat-resistant alloy can be used, and it is optimal depending on the operating pressure and operating temperature. Materials can be used.

  The coating layer can be coated with any organic or inorganic material such as rubber or fluororesin, or can be coated with metal powder such as molybdenum dioxide, aluminum or stainless steel. Further, the coating layer can be directly coated on the metal of the core material, or can be coated on a thin plate of the outer layer disposed outside the core material. When the coating layer is provided, the sealing property can be maintained even if some deformation occurs due to its elasticity.

  The dimensions of the main body 4 can take any value depending on the application. For example, when used for sealing the joint surface between the cylinder head and the cylinder block, the plane dimension is that of the cylinder head and the cylinder block. The size of the opening 6 is determined according to the size of the combustion chamber hole of the internal combustion engine. Moreover, as a thickness dimension of the main body 4, although 0.3 mm-1.5 mm can be illustrated, it is not restricted to this.

  Further, bolt holes 10 are provided at four locations around each opening 6, and the metal gasket 2 is inserted between structures to be joined (not shown), and fastening bolts (not shown). Are inserted into the bolt holes of the structure and the bolt holes 10 of the metal gasket 2 to fasten the two structures. Therefore, the metal gasket 2 receives a tightening load by the tightening force of the fastening bolt.

<Description of grommet 8>
Next, the structure of the grommet portion 8 attached to the opening 6 of the main body 4 will be described in detail with reference to partial cross-sectional views shown in FIGS. 1 (b) and 1 (c). Here, FIG. 1B is a partial cross-sectional view seen from the arrow A in FIG. 1A, and FIG. 1C is a partial cross-sectional view seen from the arrow B in FIG. .
Both cross-sectional views have the same basic structure, and the grommet portion 8 has a folded portion 8 a formed by folding a thin plate, and a collar portion 8 b where a thin plate continuous from the folded portion 8 a overlaps the main body 4. In FIG. 1B and FIG. 1C, the region where the thin plate continuous from the folded portion 8a overlaps the surface of the main body 4 is shown as a collar portion 8b, and the left region is shown as the folded portion 8a.
The manner in which the grommet portion 8 is attached to the main body 4 will be described. By inserting the substantially flat main body 4 into the inner space of the folded portion 8a generated by folding the thin plate, both members are fixed. ing. Further, the opening 6 is surrounded by the folded portion 8 a of the grommet portion 8.
In FIG. 1B and FIG. 1C, the width of the collar portion 8b is different, but the basic structure is the same. The difference in the width dimension of the collar portion 8b will be described later.

As the material of the grommet portion 8, as with the main body 4, it is possible to use a thin plate made of any metal material including stainless steel, carbon steel, aluminum, copper, and a heat resistant alloy. The optimum material can be used accordingly. Moreover, the coating layer using arbitrary materials can also be provided similarly to a main body.
Moreover, as a thickness dimension of the thin plate which comprises the grommet part 8, 0.1 mm-0.4 mm can be illustrated, but it is not restricted to this.

<Explanation regarding the width of the grommet 8>
As shown in FIG. 1A, in the present embodiment, the width of the collar portion 8b of the grommet portion 8 has a narrow region as indicated by an arrow A and a wide region as indicated by an arrow B. Here, the width of the collar portion 8 b indicates an “overlap margin” in which a thin plate continuous from the folded portion 8 a of the grommet portion 8 overlaps the main body 4. Further, as shown in FIGS. 1B and 1C, the grommet portion 8 protrudes outward from the surface of the main body 4 by the thickness of the thin plate constituting the grommet portion 8, so that it is fastened. When a tightening load is applied to the metal gasket 2 using bolts, the area around the opening 6 is mainly tightened by the grommet portion 8, more specifically, by a part of the folded portion 8a and the collar portion 8b. Will receive a load.
Therefore, when the same tightening load is applied, when the width of the collar portion 8b is large, that is, when the overlap margin is large, the tightening pressure in this region is small, and the width of the collar portion 8b is narrow, ie, the overlap margin is small. When it is small, the tightening surface pressure in this region increases.

<Description of the grommet 8 shown in FIG. 1>
As shown to Fig.1 (a), in this embodiment, the shape of the grommet part 8 with which the opening part 6 of the edge was mounted | worn among the some opening parts 6 provided in the main body 4 is shown. In this case, the fastening bolts (only the bolt hole 10 is shown in FIG. 1A) arranged on the left and right of the opening 6 shown in the center of FIG. 1A will be described. The fastening bolt has the opening 6 only on one side thereof, and the upper and lower fastening bolts on the right side of the opening 6 have the opening 6 on both sides thereof. That is, the fastening bolt arranged on the left side applies a tightening load to one opening 6, and the fastening bolt arranged on the right side applies a tightening load to two openings 6. Therefore, in principle, the tightening load by the fastening bolt arranged on the left side is twice the tightening load by the fastening bolt arranged on the right side.
If the width of the flange portion 8b is the same in one grommet portion 8, the tightening surface pressure received by the left region of the grommet portion 8 (the flange portion 8b and a part of the bent portion 8a). Is a very large value compared to the tightening surface pressure received by the region on the right side of the grommet portion 8 (a portion of the flange portion 8b and the bent portion 8a). Note that the tightening surface pressure applied to each position of the grommet portion 8 is affected not only by the position of the fastening bolt but also by the shape and rigidity of the structure. In particular, when a relatively large tightening load is applied as a whole in order to exhibit sufficient sealing performance, an excessive tightening surface pressure may be applied particularly in a region near the fastening bolt.

In order to cope with this, in this embodiment, a region where the width of the collar portion 8b of the grommet portion 8 is wide is provided in a region close to the arrangement position of the left fastening bolt. Thus, an excessive tightening surface pressure is prevented from being generated, and an optimum tightening surface pressure distribution in the peripheral region of the opening 6 can be formed. In this case, for example, the profile of the collar portion 8b capable of forming an optimum tightening surface pressure distribution can be determined by computer structural analysis using a finite element method or the like.
In addition, as shown in FIG. 1C, which is a partial cross-sectional view seen from the arrow B in FIG. 1A, in this embodiment, the flange portions 8 b of the grommet 8 are provided on both sides of the main body 4. On the both sides of the main body 4, the collar portion 8b has the same width dimension. That is, the width of the collar portion 8b is increased in the same manner. However, the present invention is not limited to this, and as shown in FIG. 2 (c), it is possible to make the width dimension of the collar portion 8b different between the upper and lower surfaces of the main body 4, and as shown in FIG. The collar portion 8b can be provided only on one side of the main body 4.
Note that FIG. 1B, which is a partial cross-sectional view seen from the arrow A in FIG. 1A, shows a cross-sectional shape of a region where the width of the collar portion 8b of the grommet portion 8 is not widened.

As described above, in FIG. 1, one embodiment of the grommet portion 8 attached to the opening 6 disposed at the end among the plurality of openings 6 provided in the metal gasket 2 is shown. Even if a large additional tightening weight is applied by the fastening bolts arranged at the end of 2, the width of the collar portion 8b of the grommet portion 8 is correspondingly increased, so that the appropriate tightening in the peripheral region of the opening 6 can be achieved. A surface pressure can be obtained.
Further, since the temporal change in the tightening surface pressure distribution due to creep characteristics or the like is small, the metal gasket can be used for a long time in a stable state. Further, since the collar portion 8b of the grommet portion 8 can be sealed by surface contact, the effective seal area can be increased, and a metal gasket structure suitable for various sealing situations can be obtained. For example, even when the joint surfaces of the structures to be fastened are not parallel, it is easy to form an effective seal surface.

Further, in addition to adjusting the width dimension of the brim portion 8b of the grommet portion 8 as described above, by adjusting the thickness of the grommet portion 8, the combination of both can more effectively reduce the tightening surface pressure distribution. Adjustments can also be made. In this case, it is relatively easy to change the thickness dimension of the grommet portion 8 formed by folding the thin plate, and the tightening surface pressure can be adjusted effectively.
Moreover, in this embodiment, as shown in FIG.1 (b) and FIG.1 (c), although the inside of the folding | returning part 8a is hollow, as shown to FIG. 5 (a) and FIG.5 (b). In addition, the core member 12 may be provided inside the folded portion 8a. In this case, the thickness dimension of the grommet portion 8 can be changed by deforming the core member 12.

  Moreover, in FIG.1 (b) and FIG.1 (c), although the main body 4 is comprised from one member, as shown in FIG.1 (d), it is not restricted to this, A some member is comprised. A stacked body 4 can also be used. 4D is a cross-sectional view as seen from the arrow B in FIG. 1A, as in FIG. 1C, and the outer layer member 4b and the outer layer member 4c are laminated on both sides of the core member 4a. Where. However, the main body 4 is not limited to a three-layer structure, and can be composed of an arbitrary number of layers.

  Further, when used to seal the joint surface between the cylinder head and the cylinder block of the internal combustion engine, the tightening load and the tightening surface pressure may be different for each cylinder. It is also conceivable to use a metal gasket 2 having a different shape of the collar portion 8b. For example, in the case of a four-cylinder internal combustion engine, the shape of the flange portion 8b of the grommet portion 8 of the metal gasket 4 attached to the cylinder # 1 to cylinder # 4 may be different.

(Description of other embodiments of the grommet 8)
Next, the grommet part 8 and other embodiments of the metal gasket 2 according to the present invention will be described with reference to FIGS.
<Description of Embodiment shown in FIG. 2>
First, with reference to FIG. 2, another embodiment of the grommet portion 8 attached to the opening 6 disposed at the end among the plurality of openings 6 provided in the metal gasket 2 will be described. Although the shape of the collar part 8b of the grommet part 8 differs between this embodiment and embodiment shown in FIG. 1, it is the same in other points. Therefore, in the following description, the description will focus on the different points.

As shown in FIG. 2A, in the present embodiment, the width of the collar portion 8b in the left region of the grommet 6 is wide as in the embodiment shown in FIG. On the other hand, in the present embodiment, the width of the collar portion 8b is wide in the entire left region. On the other hand, as shown in FIG. 2C, which is a partial cross-sectional view seen from the arrow B in FIG. 2A, the collar portion 8b on the upper surface side is widened, but the collar portion 8b ′ on the lower surface side is wide. is not.
For example, when the cylinder head and the cylinder block of the internal combustion engine are joined, the structure as in the present embodiment reduces the tightening surface pressure on the cylinder head side (upper side) having a relatively low strength, and thus a cylinder having a relatively high strength. It is conceivable to secure the sealing performance by increasing the clamping surface pressure on the block side (lower side).

Further, in the embodiment shown in FIG. 1, the width of the collar portion 8b on the right side of the drawing is not widened, but in this embodiment, as shown in FIG. 2 (a), in the vicinity of the position where the fastening bolt is arranged. In this position, the collar portion 8b has a widened area. As shown in FIG. 2D, which is a partial cross-sectional view seen from the arrow C in FIG. 2A, in this region, the upper surface side and the lower surface side are similarly widened. FIG. 2B is a partial cross-sectional view as seen from the arrow A in FIG. 2A, and shows a cross-sectional shape of a region where the width of the collar portion 8b is not widened.
As described above, also in this embodiment, an optimum tightening surface pressure can be obtained in the peripheral region of the opening 6 as in the above-described embodiment.

  Moreover, in FIG.2 (b)-FIG.2 (d), although the main body 4 is comprised from one member, as shown in FIG.2 (e), it is not restricted to this, A some member is comprised. A stacked body 4 can also be used. 2 (e) is a cross-sectional view as seen from the arrow C in FIG. 2 (a), as in FIG. 2 (d). The outer layer member 4b and the outer layer member 4c are laminated on both sides of the core member 4a. Where. However, the main body 4 is not limited to a three-layer structure, and can be composed of an arbitrary number of layers.

<Description 2 of embodiment shown in FIG. 3>
Next, with reference to FIG. 3, one embodiment of the grommet portion 8 attached to the opening 6 disposed at an intermediate position (a position that is not the end) among the plurality of openings 6 provided in the metal gasket 2. Will be explained. In addition, although the shape of the collar part 8b of the grommet part 8 differs between this embodiment and embodiment shown in FIG. 1, it is the same in other points. Therefore, in the following description, the description will focus on the different points.

In this embodiment, the area | region where the width | variety of the collar part 8b of the grommet part 8 spread partially is provided in four places near the position where the fastening bolt is arrange | positioned. As a result, it is possible to obtain an appropriate tightening pressure distribution by preventing an excessive tightening surface pressure from being generated in a region that is strongly influenced by the tightening force of the tightening bolt.
Here, FIG. 3B, which is a partial cross-sectional view seen from the arrow A in FIG. Further, FIG. 3C, which is a partial cross-sectional view seen from the arrow B in FIG.

  Moreover, in FIG.3 (b) and FIG.3 (c), although the main body 4 is comprised from one member, as shown in FIG.3 (d), it is not restricted to this, A some member is comprised. A stacked body 4 can also be used. 3D is a cross-sectional view as seen from the arrow B in FIG. 3A, as in FIG. 3C, and the outer layer member 4b and the outer layer member 4c are laminated on both sides of the core member 4a. Where. However, the main body 4 is not limited to a three-layer structure, and can be composed of an arbitrary number of layers.

<Description of Embodiment shown in FIG. 4>
Next, with reference to FIG. 4, another embodiment of the grommet portion 8 attached to the opening 6 arranged at an intermediate position (a position that is not an end) among the plurality of openings 6 provided in the metal gasket 2. Will be explained. In addition, although the shape of the collar part 8b of the grommet part 8 differs between this embodiment and embodiment shown in FIG. 3, it is the same in other points. Therefore, in the following description, the description will focus on the different points.

In the embodiment shown in FIG. 3, a region where the width of the collar portion 8 b of the grommet portion 8 is partially provided. That is, the width dimension of the collar part 8b of the grommet part 8 changes discontinuously. However, in this embodiment, the width dimension of the collar part 8b of the grommet part 8 is continuous as shown in FIG. The collar portion 8b of the grommet portion 8 has a continuous and smooth outer shape. By such a continuous change in the width dimension of the brim portion 8b of the grommet portion 8, it is possible to form a finer and more appropriate tightening pressure distribution. In this case, for example, the profile of the collar portion 8b capable of forming an optimum tightening surface pressure distribution can be determined by computer structural analysis using a finite element method or the like.
Here, FIG. 4B, which is a partial cross-sectional view seen from the arrow A in FIG. 4A, shows the cross-sectional shape of the point where the width dimension of the collar portion 8b of the grommet portion 8 is the narrowest. Further, FIG. 4C, which is a partial cross-sectional view seen from the arrow B in FIG. 4A, shows a cross-sectional shape at a point where the width dimension of the collar portion 8b of the grommet portion 8 is most widened.

  4 (b) and 4 (c), the main body 4 is composed of one member. However, the present invention is not limited to this, and as shown in FIG. A stacked body 4 can also be used. FIG. 4D is a cross-sectional view as seen from the arrow B in FIG. 4A as in FIG. 4C, and the outer layer member 4b and the outer layer member 4c are laminated on both sides of the core member 4a. Where. However, the main body 4 is not limited to a three-layer structure, and can be composed of an arbitrary number of layers.

(Description of other embodiments of metal gasket according to the present invention)
<Description of Embodiment shown in FIG. 5>
FIG. 5 is a partial cross-sectional view showing the structure around the grommet portion 8, and shows an embodiment in which the core member 12 is provided in the internal space of the folded portion 8 a of the grommet portion 8. FIG. 5A shows a grommet 8 provided with a core member 12 having a circular cross-sectional shape. FIG. 5B shows a grommet provided with a core member 12 having a rectangular cross-sectional shape. Part 8 is shown. These can select the core member 12 of the optimal cross-sectional shape according to a use and use conditions. In the grommet portion 8 of the present embodiment, a larger tightening load can be received depending on the strength of the core member 12.
Further, as described above, for example, by deforming the core member 12, the thickness of the grommet 8 is changed to change the width dimension of the collar portion 8 b of the grommet portion 8 and the thickness dimension of the grommet portion 8. Can be combined to form an optimum tightening surface pressure distribution.

<Description of Embodiment shown in FIG. 6>
FIG. 6 is a cross-sectional view illustrating the structure of the metal gasket 2 including the main body 4 and the grommet portion 8. In this embodiment, the grommet portion 8 is formed integrally with the main body 4.
First, the embodiment shown in FIG. 6A will be described. The main body 4 has a three-layer structure in which an outer layer member 4b and an outer layer member 4c are laminated on both surfaces of a core member 4a. Further, the lower outer layer member 4b extends beyond the core member 4a, the outer layer member 4b is folded back to form a folded portion 8a, and the outer layer member 4b overlaps with the outer layer member 4c of the main body 4 to form a collar portion. 8b is formed. Therefore, in the present embodiment, the collar portion 8b is provided on the upper side, but not on the lower side. However, the width dimension of the upper collar portion 8b can be changed in an arbitrary manner as in the embodiment shown in FIGS.

  On the other hand, in the embodiment shown in FIG. 6B, the main body 4 has a two-layer structure in which the outer layer member 4b is laminated on the lower surface of the core member 4a. The lower outer layer member 4b extends beyond the core member 4a, the outer layer member 4b is folded back to form a folded portion 8a, and the outer layer member 4b is overlapped with the core member 4a of the main body 4 so 8b is formed. Also in the present embodiment, the collar portion 8b is provided on the upper side, but not on the lower side, as described above. However, the width dimension of the upper collar portion 8b can be changed in an arbitrary manner as in the embodiment shown in FIGS.

<Other embodiments>
Embodiments of the metal gasket according to the present invention are not limited to the above-described embodiments, and various other embodiments are included in the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The metal which concerns on this invention is a figure which shows one embodiment of a gasket, (a) shows a top view, (b) and (c) The partial sectional view is shown, (d) A main body is 3 layer structure The fragmentary sectional view in the case of is shown. The metal which concerns on this invention is a figure which shows other embodiment of a gasket, (a) shows a top view, (b)-(d) shows the fragmentary sectional view, (e) has three layers of main bodies A partial sectional view in the case of a structure is shown. The metal which concerns on this invention is a figure which shows other embodiment of a gasket, (a) shows a top view, (b) and (c) The partial sectional view is shown, (d) A main body is a three-layer structure The fragmentary sectional view in the case of is shown. The metal which concerns on this invention is a figure which shows other embodiment of a gasket, (a) shows a top view, (b) and (c) The partial sectional view is shown, (d) A main body is a three-layer structure The fragmentary sectional view in the case of is shown. It is sectional drawing which shows the grommet part other embodiment which concerns on this invention. It is sectional drawing which shows other embodiment of the metal gasket which concerns on this invention.

Explanation of symbols

2 Metal gasket 4 Main body 4a Core member 4b Outer layer member 4c Outer layer member 6 Opening portion 8 Grommet portion 8a Folded portion 8b, 8b 'Collar portion 10 Bolt hole 12 Core member

Claims (4)

A substantially flat main body having an opening and a coating layer on the outside;
A grommet part that is a separate member from the main body , has a folded part formed by folding a thin plate, and surrounds the opening by the folded part;
A metal gasket with
The grommet portion is formed with a collar portion that is a portion where the thin plate continuous from the folded portion overlaps the main body,
In the same grommet part, the width of the collar part is not constant,
In the case where the metal gasket is inserted between a cylinder head and a cylinder block of a diesel engine, the cylinder head and the cylinder block are fastened by a fastening member, and the joint surface of the cylinder head and the cylinder block is sealed.
Based on the position of the fastening member and the rigidity of the cylinder head and the cylinder block , the width of the collar portion is determined so as to form a predetermined tightening surface pressure distribution in the peripheral region of the opening,
In at least one of the upper and lower surfaces of the metal gasket, the width of the flange portion in the vicinity of the fastening member that is disposed on an end portion of the metal gasket, than the width of the flange portion of the other region Te wide Kuna' And
Of the upper surface and the lower surface of the metal gasket, the width of the collar portion on one surface is wider than the width of the collar portion on the other surface, and the strength of the cylinder head and the cylinder block is increased. A metal gasket for a diesel engine , characterized in that the metal gasket is inserted so that the surface on the side where the flange portion is wider contacts the weaker side . A substantially flat main body provided with an opening;
A grommet part that is a separate member from the main body , has a folded part formed by folding a thin plate, and surrounds the opening by the folded part;
A metal gasket with
The grommet portion is formed with a collar portion that is a portion where the thin plate continuous from the folded portion overlaps the main body,
In the same grommet part, the width of the collar part is not constant,
In the case where the metal gasket is inserted between a cylinder head and a cylinder block of a diesel engine, the cylinder head and the cylinder block are fastened by a fastening member, and the joint surface of the cylinder head and the cylinder block is sealed.
Based on the position of the fastening member and the rigidity of the cylinder head and the cylinder block , the width of the collar portion is determined so as to form a predetermined tightening surface pressure distribution in the peripheral region of the opening,
In at least one of the upper surface and the lower surface of the metal gasket, the width of the collar portion in the vicinity of the fastening member arranged at the end of the metal gasket is wider than the width of the collar portion in the other region. ,
Of the upper surface and the lower surface of the metal gasket, the width of the collar portion on one surface is wider than the width of the collar portion on the other surface, and the strength of the cylinder head and the cylinder block is increased. Insert the metal gasket so that the surface on the wide side of the collar portion is in contact with the weaker side,
Furthermore, a core member is provided inside the folded portion of the grommet portion. A substantially flat main body provided with an opening;
A grommet part that is a separate member from the main body , has a folded part formed by folding a thin plate, and surrounds the opening by the folded part;
A metal gasket with
The grommet portion is formed with a collar portion that is a portion where the thin plate continuous from the folded portion overlaps the main body,
In the same grommet part, the width of the collar part is not constant,
In the case where the metal gasket is inserted between a cylinder head and a cylinder block of a diesel engine, the cylinder head and the cylinder block are fastened by a fastening member, and the joint surface of the cylinder head and the cylinder block is sealed.
Based on the position of the fastening member and the rigidity of the cylinder head and the cylinder block , the width of the collar portion is determined so as to form a predetermined tightening surface pressure distribution in the peripheral region of the opening,
In at least one of the upper surface and the lower surface of the metal gasket, the width of the collar portion in the vicinity of the fastening member arranged at the end of the metal gasket is wider than the width of the collar portion in the other region. ,
Of the upper surface and the lower surface of the metal gasket, the width of the collar portion on one surface is wider than the width of the collar portion on the other surface, and the strength of the cylinder head and the cylinder block is increased. Insert the metal gasket so that the surface on the wide side of the collar portion is in contact with the weaker side,
Furthermore, in the same grommet part, the thickness of the grommet part is not constant,
The metal gasket according to claim 1, wherein the predetermined tightening surface pressure distribution in the peripheral region of the opening is formed by a combination of a width dimension of the collar portion and a thickness dimension of the grommet portion. In the case of sealing the joint surface between the cylinder head and the cylinder block of the diesel engine having a plurality of cylinders, characterized in that the shape of the flange portion of the metal gasket to be attached to each cylinder varies The metal gasket according to any one of claims 1 to 3 .

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