JP2008215467A - Metal gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal gasket 1 capable of enhancing performance with a simple structure by suppressing the costs. <P>SOLUTION: An auxiliary plane 3 is laminated only around a combustion chamber hole 4a of a substrate 2 made of a strong metal plate. Combustion chamber hole side beads 8a, 8b are molded in the substrate 2 and the auxiliary plate 3 to surround the combustion chamber hole 4a. Wall thickening portions 10, 12 are formed around an outer peripheral end of the substrate 2 and a bolt hole 6. The wall thickening portion is adjusted in height so that the total wall thickness of a position provided with the wall thickening portions 10, 12 is less than the total wall thickness composed of the laminated substrate 2 and the auxiliary plate 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal gasket that is used by being interposed between facing surfaces of a cylinder block and a cylinder head that constitute an engine, and the cylinder block and the cylinder head are interposed with a metal gasket. The present invention relates to the metal gasket used in a bolted engine.

As a conventional metal gasket, there are metal gaskets described in Patent Document 1 and Patent Document 2, for example.
The metal gasket described in Patent Document 1 is formed by laminating two substrates made of an elastic metal plate, opening a combustion chamber hole for each substrate, and sealing the combustion chamber gas around the combustion chamber hole. A combustion chamber hole side bead made of a full bead is molded, and a bead is molded and sealed around a hole that needs to be sealed among a cooling water hole, an oil hole, a bolt hole, etc. formed at the outer peripheral position of the combustion chamber side bead. is doing. Further, a shim plate is sandwiched between the two stacked substrates only around the combustion chamber hole, and the connection between the shim plate and the substrate is performed by the combustion chamber gas on one of the two substrates. Is fixed to the flat portion of the molded bead on the combustion chamber hole side by welding.

  That is, by increasing the total thickness around the combustion chamber holes by arranging shim plates, the shim plates are arranged only around the combustion chamber holes between the bolt holes when mounted on the engine and fastened with bolts. By deforming the cylinder head (joint surface) by the thickness, the surface pressure around the combustion chamber hole increases to seal high combustion gas pressure, and the vibration amplitude repeatedly caused by explosion due to operation to the bead is small To prevent fatigue failure of metal beads.

In addition, the metal gasket described in Patent Document 2 has a sub plate provided only around the combustion chamber hole for one substrate made of an elastic metal plate, and combustion gas around the combustion chamber hole is provided on both the substrate and the sub plate. It is a metal gasket which molded the combustion chamber hole side bead which consists of a full bead which seals. The bead trajectory to be molded on the sub-plate of the molded combustion chamber hole side bead is shifted by a quarter of the maximum bead width with respect to the bead trajectory molded on the substrate in the vicinity of the bolt hole, and the bolt holes are the same. The track is gradually changed at the boundary between the two. As a result, by partially changing the deformation stress of the bead that is generated when the metal gasket is mounted on the engine and fastened with a bolt, the limited bolt axial force is effectively used and generated around the combustion chamber hole. The surface pressure of the bead is averaged.
Patent No. 3314371 Japanese Patent No. 3553099

After that, engine technology has continued to evolve rapidly, and for example, engine rigidity tends to decrease due to the reduction in size and weight of the engine, higher performance, increased heat load due to the introduction of energy-saving mechanisms, and the introduction of high-mechanical technologies. As a result, there are various techniques for sealing gases and liquids with different conditions, such as cooling water for cooling high-temperature and high-pressure combustion gas, generated engine heat, and oil for lubricating the engine rotating sliding part, with a single metal gasket. There is a problem.
In the current situation where cost competitiveness is forced by the tendency to procure parts from the global market due to the response to such a decrease in engine rigidity and the spread of the Internet, demands in terms of both performance and cost are becoming increasingly severe.
Further, it is difficult to follow the evolution technology of the engine, and problems occur depending on the use conditions of the engine.

  For example, in Patent Document 1 and Patent Document 2, the periphery of the combustion chamber hole is thickened with a shim plate to seal the combustion gas at the center, but the outer end portion extends beyond the oil return hole that protrudes outside the bolt hole. Paying attention to the outer peripheral edge of the substrate, there is a difference in thermal expansion due to the time difference in temperature rise between the opposing joint surface between the cylinder head and the cylinder block that occurs in the early stage of engine operation and the engine part away from the joint surface. The corresponding joint surfaces are deformed in a warping direction (deformed in a direction in which a gap at the outer peripheral portion is increased). Although this deformation can be corrected by the axial force of the bolt between the bolt holes sandwiching the combustion chamber hole, the thickness of the shim plate provided around the combustion chamber hole located between the bolt holes Only the cylinder head is deformed at the bolt hole. Of course, for this reason, a high surface pressure is generated in the thickened portion around the combustion chamber hole with the shim plate. However, since there is nothing that corrects the deformation of the joint surface outside the bolt hole, opening occurs between the corresponding joint surfaces outside the oil return hole due to a temperature difference. By repeating this opening, the seal surrounding the oil return hole deteriorates with time, causing oil leakage from the oil return hole.

The above opening phenomenon stops when the operation continues and the temperature of the entire engine is leveled, but the sealing material applied to the gasket surface due to repeated operation stops the sliding caused by repeated opening Oil leakage may increase due to a decrease in the sealing force due to cutting or deterioration of the durability of the seal. This phenomenon is significant in areas with large temperature differences such as cold regions.
Due to this phenomenon, the same problem may occur in both Patent Documents 1 and 2.
An object of the present invention is to provide a metal gasket capable of improving performance with a simple structure while suppressing cost.

In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention can generate a spring with a substrate made of an elastic metal plate capable of generating a spring and a thickness that is the same as or different from the plate thickness of the substrate. A sub-plate made of a flexible metal plate and disposed opposite to a part of the substrate in the thickness direction,
The substrate has a combustion chamber hole side bead formed by processing the substrate in the plate thickness direction so that the combustion chamber hole is opened and surrounds the combustion chamber hole, and is formed on the outer peripheral side of the combustion chamber hole side bead. The cooling water hole is opened and a second bead is provided so as to surround the outer periphery of the cooling water hole, and the bolt hole is opened outside the second bead,
A combustion chamber hole-side bead formed by processing the sub-plate in the thickness direction so as to surround the combustion chamber hole and also has a combustion chamber hole corresponding to the combustion chamber hole of the substrate also in the sub plate. Molded, and the outer peripheral end position of the sub-plate is set to be on the outer peripheral side with respect to the combustion chamber hole side bead forming position on the substrate and on the inner peripheral side with respect to the second bead forming position,
A thickened portion is provided for the substrate portion located outside the second bead, and the total plate thickness at the position where the thickened portion is provided is greater than the total plate thickness composed of the laminated substrate and sub-plate. The height of the thickened portion is adjusted so as to be small.

  In the present invention, the laminated portion of the metal plate is only around the combustion chamber hole, so that an inexpensive metal gasket is obtained. In addition, by making the total plate thickness around the combustion chamber hole, which is the laminated portion, the largest, the surface pressure at the time of bolt tightening is maximized around the combustion chamber hole to seal the combustion gas. Also, by providing a thickened portion on the substrate portion outside the second bead on the outer periphery of the cooling water hole, which is a non-laminated portion with the sub-plate with respect to the substrate, the joint surface between the cylinder head and the cylinder block at the time of bolt tightening By adjusting the deformation, the seal surface pressure around the combustion chamber hole can be adjusted.

That is, a difference in thickness is generated in the portion outside the cooling water hole because there is no sub-plate. This thickness difference is too large depending on the rigidity of the engine in the distance between the bolt hole and the cooling water hole part. For the purpose of adjusting this difference, for example, the bolt hole or A thickened portion is provided on either the outer end of the oil return hole, or both the outer end of the bolt hole and the oil return hole. That is, an appropriate thickened portion is provided so that the joint surface is deformed to an optimal deformation amount that generates an optimal surface pressure around the combustion chamber hole.
In addition, when it is provided on both the bolt hole and the outer end of the oil return hole, the thickness of the thickened portion provided on the outer end of the oil return hole is equal to or greater than the thickness of the thickened plate provided around the bolt hole. It is preferable to do.

Next, the invention described in claim 2 is characterized in that at least a part of the thickened portion is provided around the bolt hole in the configuration described in claim 1.
Here, the periphery of the bolt hole is a portion at least partially facing the bolt seat surface in a plan view.
By providing the thickened portion around the bolt hole that is directly involved in the deformation of the joint surface by tightening the bolt, the deformation of the joint surface at the time of bolt tightening can be adjusted efficiently.

Next, the invention described in claim 3 is characterized in that at least a part of the thickened portion is provided at an outer peripheral end portion of the substrate with respect to the configuration described in claim 1 or claim 2. It is.
According to the present invention, the deformation in the warping direction on the outer peripheral side of the joint surface is applied by pre-loading by the thickened portion provided at the outer peripheral end of the substrate by bolt tightening.
This action is as follows. That is, in the present invention, the opening phenomenon on the outer peripheral side between the joint surfaces caused by warping deformation of the joint surfaces caused by the difference in thermal expansion, which occurs in the initial operation of the engine, is described in advance in the present invention. By preloading the joint surface with a preload that deforms in the warping direction, the deformation in the opening direction due to the difference in thermal expansion at the outer peripheral portion of the joint surface is reduced to zero or reduced, thereby suppressing deterioration of the seal on the outer peripheral side of the substrate.

Next, the invention described in claim 4 includes the second bead and the outside of the second bead formation position with respect to the configuration described in any one of claims 1 to 3. Each of the beads to be formed is constituted by any one of the following (a) and (b).
(A) A bead is comprised with the heat-resistant elastic soft sealing material fixed to both surfaces of the board | substrate.
(B) The bead is composed of a synthetic bead composed of a metal bead obtained by processing the substrate itself in the plate thickness direction and a heat-resistant elastic soft sealing material fixed to both surfaces of the metal bead.
When the bolts are tightened, the load increases around the combustion chamber hole and a large seal pressure is generated at the combustion chamber hole side bead. In addition, in the bead formed on the substrate in the non-laminated portion with the sub plate, the load is smaller than that around the combustion chamber, but by using the bead of the present invention, the contact portion with the joint surface becomes a soft sealing material. Thus, even if the surface can be sealed and the load is relatively low, sufficient sealing is possible.

Next, in the invention according to claim 5, with respect to the structure according to any one of claims 1 to 4, at least one of the substrate and the sub-plate, the combustion chamber hole more than the combustion chamber hole side bead. Combustion chamber hole side bead formed by processing the flat part at least on the flat part on the combustion chamber hole side among the flat parts on the side and the flat part on the cooling water hole side with respect to the combustion chamber hole side bead It is characterized by adding a seal line by molding one or more lower beads.
By providing the auxiliary plate only around the combustion chamber holes, the joint surfaces between the bolt holes sandwiching the combustion chamber holes at the time of bolt tightening are deformed so that the distance between the joint surfaces around the combustion chamber holes becomes large. At this time, as described in claim 1, by providing the thickened portion on the outer peripheral side of the substrate, particularly around the bolt hole, the deformation of the joint surface is alleviated, but the combustion chamber is still more than the combustion chamber hole side bead. There is a tendency for the gap between the joint surfaces to increase on the hole side.

On the other hand, in the present invention, one or more auxiliary beads are formed at least on the flat portion on the combustion chamber side with respect to the combustion chamber hole side bead, so that the joint surface is closer to the combustion chamber hole side than the combustion chamber hole side bead. It is possible to seal the gap corresponding to the gap, and the sealing of the combustion gas becomes more reliable.
Here, the thickness of the sub plate relative to the thickness of the substrate may be adjusted based on the hardness of the engine. In other words, by providing a plate thickness difference between the board thickness and the board thickness, it is possible to further adjust the deformation of the joint surface, and to expand the rigidity adaptability range of an engine equipped with a metal gasket. It is possible to adjust the deformation at the three portions of the periphery of the combustion chamber hole and the outer end of the bolt hole and the oil return hole. Further, it is possible to use a technique for effectively using a limited tightening load by changing the auxiliary bead width and widening the vicinity of the bolts along the circumferential direction and narrowing the space between the bolts.

  According to the present invention, it is possible to adjust the deformation of the joint surface of the cylinder block and the cylinder head of the engine to an appropriate deformation while ensuring a seal around the combustion chamber hole, resulting in a simple structure while suppressing cost Thus, it is possible to improve the performance, and it is possible to provide an inexpensive metal gasket while maintaining the performance.

Next, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view showing a state in which the metal gasket 1 according to the present embodiment is partially cut away. 2 is a cross-sectional view taken along the line CC of FIG.
(Constitution)
First, the configuration will be described. As shown in FIGS. 1 and 2, a substrate 2 and a sub-plate 3 made of an elastic metal plate capable of generating a spring force such as a steel material are arranged to face each other. For example, the thickness is the same as or equivalent to that of the substrate 2 and the sub-plate 3. However, the plate thickness may be different.
As shown in FIG. 1, the substrate 2 has a plurality of combustion chamber holes 4 a provided corresponding to the combustion chambers of the engine, which are aligned in a predetermined direction. Further, a combustion chamber hole side bead 8a is molded on the substrate 2 so as to surround the combustion chamber hole 4a in an endless manner. The combustion chamber hole side bead 8a is a full bead formed by deforming the substrate 2 itself in the plate thickness direction. However, it may be a stepped half bead.

  A plurality of cooling water holes 5 are formed on the substrate portion on the outer peripheral side of the combustion chamber hole side bead 8a at positions facing the engine cooling water region (space through which the cooling water passes) in the plate thickness direction. A plurality of holes are formed along the hole-side beads 8a. Further, an outer peripheral bead 9 as a second bead is formed on the outer peripheral side of the plurality of cooling water holes 5 so as to surround the plurality of cooling water holes 5 formed along the combustion chamber hole side beads 8a. ing. FIG. 2 illustrates a case where the outer peripheral bead 9 is provided as a stepped half bead formed by deforming the substrate 2 in the plate thickness direction.

Further, a bolt hole 6 and an oil hole 7 are formed in the board portion outside the outer peripheral side bead 9, and a third bead 11 is separately formed and sealed in a portion requiring a seal such as around the oil hole 7. ing. The third bead 11 may be formed of a stepped half bead formed by deforming the substrate 2 in the plate thickness direction, for example.
In addition, the sub-plate 3 arranged to face the substrate 2 in the plate thickness direction as described above is laminated with the substrate 2 on the combustion chamber hole 4 a side of the substrate 2. That is, the combustion chamber hole 4b having the same shape is opened at the same position as the combustion chamber hole 4a of the substrate 2 also on the sub plate 3, so that the inner peripheral side (combustion chamber hole 4b side) of the sub plate 3 is Is disposed at the same position as or equivalent to the inner peripheral side (combustion chamber hole 4a side). But the diameter of the combustion chamber hole 4a of the board | substrate 2 and the diameter of the combustion chamber hole 4b of the subplate 3 may be changed a little.

Further, the outer peripheral side end of the sub-plate 3 is set so as to be positioned between the combustion chamber hole side bead 8 a and the outer peripheral side bead 9 formed in the substrate 2. For example, the outer peripheral side of the sub-plate 3 is set at a position that overlaps the cooling water region formed in the cylinder block 50 (see FIG. 11).
The sub-plate 3 is also molded with a combustion chamber hole side bead 8b that surrounds the combustion chamber hole 4b in an endless manner. The combustion chamber hole side bead 8b is formed of a full bead formed by deforming the sub plate 3 in the plate thickness direction. But you may shape | mold the combustion chamber hole side bead 8b in a step-shaped half bead. Note that a cooling water hole is formed in a portion of the substrate 2 facing the cooling water hole 5.

The sub-plate 3 is fixed to the substrate 2 at a position facing the cooling water region of the cylinder block 50. Reference numeral 13 denotes the hooking portion. By connecting the substrate 2 and the sub plate 3 in the cooling water region, the bead of the substrate 2 and the bead of the sub plate 3 can freely follow the deformation during operation after being fastened to the engine. .
Here, among the beads provided on the substrate 2, the height of the bead in the portion not facing the sub-plate 3 other than the periphery of the combustion chamber hole 4 a must be considered by the thickness of the sub-plate 3.

FIG. 3 shows a cross-sectional view of a portion between the combustion chamber holes 4a. Since the interval is narrow in the combustion chamber hole 4a, the two combustion chamber hole side beads 8a and 8b are joined together to form a single bead. However, as shown in FIG. 4, the combustion chamber hole side beads 8 a and 8 b may not be merged as half beads.
Further, in the present embodiment, the thick metal plate 12 a is thickened by fixing the thin metal plate 12 a to the portion between the bolt holes 6 along the circumferential direction at the outer peripheral end portion of the substrate 2 to become the thickened portion 12. ing.

  In addition, as shown in FIG. 5, the thickness of the shim plate 10 a is also increased around the bolt hole 6 by the folded eyelet method to form the thickened portion 10. The thickened portion 10 around the bolt hole 6 may be thickened by fixing a thin metal plate 10b to the periphery of the bolt hole 6 instead of the eyelet as shown in FIG. 6 which is a BB cross section of FIG. In the eyelet, the bolt hole 6 is enlarged and the eyelet is hung. However, with this eyelet, the thickness of the shim plate 10a cannot be made very thin. In addition, there are cases where the periphery of the bolt hole 6 is limited and the area is not wide enough. In this case, the configuration as shown in FIG. 6 is adopted, and the area of the metal 10b for increasing the thickness is increased by filling the bolt hole 6 to the limit. That is, it is necessary to consider how much thickening area is required. For example, since the engine material is an aluminum alloy, the rigidity is low, and if the load directly under the bolt hole 6 is large and the area is small, the engine may be depressed. Furthermore, in this embodiment, when there is anxiety about the area, the area of the thickened portion is gained by providing the thickened portions on both the thickened portion 10 at the periphery of the bolt 52 and the thickened portion 12 at the outer peripheral end. It becomes an inexpensive product that can lower the surface pressure.

Further, when a hole to be sealed, for example, an oil hole 7 is formed outside the position where the bolt hole 6 is formed, and a bead 11 surrounding the oil hole 7 is formed, as shown in FIG. The thickened portion 12 is formed by fixing the thin plate 12b at the outer peripheral end.
Here, the amount of the thickening is adjusted so that the total thickness of the thickening portions 10 and 12 is smaller than the total thickness at the position where the sub-plate 3 is laminated.
The total plate thickness of the thickened portion 12 at the outer peripheral end portion of the substrate 2 and the total plate thickness of the thickened portion 10 around the bolt hole 6 are the total plate thickness of the thickened portion 12 on the outer peripheral end portion side of the substrate 2. The total thickness of the thickened portion 12 at the outer peripheral edge of the substrate 2 and the total thickness of the thickened portion 10 around the bolt hole 6 are set to the same thickness.

(Function and effect)
The sub-plate 3 laminated on the substrate 2 is only around the combustion chamber hole 4a, and the inexpensive metal gasket 1 is obtained.
Further, when the metal gasket 1 composed of the substrate 2 and the sub-plate 3 is inserted between the joint surface S of the cylinder block 50 and the cylinder head 51 and the engine is tightened with the bolt 52, the sub-plate 3 is arranged. Around the combustion chamber hole 4a, the total plate thickness of the portion is the largest. Therefore, the surface pressure is made highest around the combustion chamber hole 4a to seal the combustion gas with a high sealing pressure.
Further, by providing the thickened portions 10 and 12 in the substrate portion on the outer peripheral side of the outer peripheral bead 9 on the outer periphery of the cooling water hole 5 that is a non-laminated portion with the sub-plate 3 with respect to the substrate 2, a cylinder at the time of tightening the bolt 52 is provided. Since the deformation of the joint surface S between the head 51 and the cylinder block 50 can be adjusted, the seal surface pressure around the combustion chamber hole 4a can be adjusted.

  That is, a difference in thickness is generated in the portion outside the cooling water hole 5 due to the absence of the sub plate 3. This difference in plate thickness is too large at the distance between the bolt hole 6 and the cooling water hole 5 depending on the tightening load and the rigidity of the engine. As a result, for example, a depression occurs in the joint surface S made of an aluminum alloy and the combustion chamber hole 4a. In some cases, the surrounding load may be reduced by that amount. On the other hand, by providing the thickened portions 10 and 12 on the substrate portion outside the outer peripheral bead 9 which is a non-laminated portion with the sub-plate 3, The deformation of the joint surface S due to the difference in the plate thickness of the sub-plate 3 is alleviated, that is, the joint surface S is set to an optimum deformation amount so as to generate an optimum surface pressure around the combustion chamber hole 4a by the thickened portions 10 and 12. Can be deformed. It is particularly suitable for a soft aluminum alloy engine.

Even in this case, the load around the combustion chamber hole 4a is increased by making the total thickness of the sub-plate 3 stacking position thicker than the total thickness of the thickened portions 10 and 12.
At this time, by providing the thickened portion 10 around the bolt hole 6 that is directly involved in the deformation due to the tightening of the bolt 52, the deformation of the joint surface S when the bolt 52 is tightened can be adjusted efficiently.

  In addition, when the thickened portion 12 (outer portion than the oil hole 7) is provided at the outer peripheral end portion of the substrate 2, the joint surfaces S are separated from each other by tightening the bolt 52 with respect to the joint surface S located outside the bolt hole 6. It is possible to apply a preload that gives deformation to warp. That is, when the total plate thickness around the combustion chamber hole 4a is maximized, the joint surface S has a large space between the joint surfaces S on the combustion chamber hole 4a side by tightening the bolt 52, and the joint surface S at the bolt hole 6 position. There is a tendency to incline so that the interval between them becomes small. On the other hand, in this embodiment, by providing the thickened portion 12 on the substrate 2 on the outer peripheral side with respect to the bolt hole 6 position at a distance from the combustion chamber hole 4a, as shown in FIG. Thus, a preload that slightly warps the outer peripheral portion is applied. In FIG. 7, a broken line L is a deformation line of the cylinder head 51. FIG. 8 shows a case where the thickened portion 10 around the bolt hole 6 is omitted, and FIG. 9 shows a schematic diagram of the deformation of the joint surface S in that case.

  As a result, the opening phenomenon on the outer peripheral side between the joint surfaces S caused by the warp deformation of the joint surface S caused by the difference in thermal expansion, which occurs in the initial operation of the engine, described in the above-described problem, Since an initial load is applied to the joining surface S with a force for deforming in the warping direction, deformation in the opening direction due to a difference in thermal expansion at the outer peripheral portion of the joining surface S is zero or reduced. As a result, deterioration of the seal on the outer peripheral side of the substrate 2 is suppressed.

Further, each of the thickened portions 10 and 12 also has an effect of preventing over-compression of the beads provided on the sub-plate 3 and the substrate 2 at the non-laminated position. This action is particularly effective when a soft sealing material as described later is used.
The same applies to the case where the oil hole 7 to be sealed is provided outside the bolt hole 6, and the difference in thermal expansion that occurs in the initial operation of the engine can be achieved by providing a thickened portion on the outer peripheral side of the oil hole 7. It is possible to suppress the opening phenomenon on the outer peripheral side between the joint surfaces S due to warping deformation of the joint surface S due to the above, and to suppress the deterioration of the bead sealing the periphery of the oil hole 7 with time.

(application)
Here, in the above embodiment, the thickened portions 10 and 12 are provided on both the periphery of the bolt hole 6 and the outer peripheral edge of the substrate 2, but the thickened portion may be provided on only one of them. Moreover, you may provide a thickened part in the other position which receives little bolt load. FIG. 8 described above is an example in which the thickened portion 10 around the bolt hole is omitted. FIG. 10 omits the thickened portion 12 located outside the bolt hole 6. FIG. 11 shows a schematic diagram of the deformation of the joint surface S in this case. Even in this case, it is preferable to provide the thickened portion 12 (the portion thickened by the plate 12a) positioned between the bolt holes 6 along the circumferential direction.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings. Note that components similar to those in the above-described embodiment will be described with the same reference numerals.
(Constitution)
The basic configuration of the present embodiment is the same as that of the first embodiment, but the outer peripheral side beads 9 and the third beads 11 are fixed to the flexible sealing materials 16a and 16b having elastic heat resistance as shown in FIG. Formed.
Other configurations are the same as those in the above embodiment.

(Function and effect)
The soft sealing materials 16a and 16b include rubber and resin-based sealing materials, and the height, width and hardness can be freely designed, and the amount of follow-up deformation is large. It is optimal for seals with a large plate thickness with the external seal. Note that a thickened portion is necessary to prevent over-compression of the sealing material.
When the bolt 52 is tightened, the load increases around the combustion chamber hole 4a, and a large seal pressure is generated at the combustion chamber hole side bead 8a. Further, in the beads 9 and 11 formed on the substrate 2 in the non-laminated portion with the sub plate 3, the load is smaller than that around the combustion chamber hole 4a. Since the contact portions are made of the soft sealing materials 16a and 16b, sufficient sealing is possible even if the surface can be sealed and the load is relatively low.

  That is, a bead made of the soft sealing materials 16a and 16b having heat resistance and elasticity has a small gasket coefficient and can apply a large generated load. In addition, the conformability is good, the processing roughness of the joint surface S can be absorbed, and the bead seal width can be widely suppressed even for the cast hole generated during casting, which is a defect of the aluminum engine. In addition, the amount of follow-up deformation is large, and there is also an effect that the sealing material is not easily scraped off by the engine movement.

(application)
Instead of forming the beads only from the soft sealing materials 16a and 16b having the elastic heat resistance, a bead configuration as shown in FIG. 13 may be used. That is, the substrate 2 is deformed in the thickness direction to form a metal bead 9a, elastic heat resistant soft sealing materials 16a and 16b are molded on both sides of the metal bead 9a, and the metal bead 9a and the rubber bead are formed. It is good also as the bead 9 by a synthetic spring. It becomes possible to earn more sealing pressure. That is, the spring of the metal bead 9a and the elasticity of the sealing materials 16a and 16b are combined to generate a sealing surface pressure. Unlike a bead of only a sealing material, it is suitable for a high internal pressure seal with little deformation even at high internal pressure. In addition, since the deformation of the sealing material is restricted by the metal beads, the sealing material can be prevented from being deformed more than necessary even under high pressure, and the sealing can be secured for a long period of time.
The surface pressure is adjusted by increasing the thickening part that limits over-compression of the sealing material around the bolt hole 6 and / or the outer peripheral edge of the substrate 2 and adjusting it with the width, height and hardness of the sealing material. do it.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings. In addition, about the components similar to said each embodiment, the same code | symbol is attached | subjected and demonstrated.
(Constitution)
The basic configuration of this embodiment is the same as that of the first and second embodiments, but as shown in FIGS. 14 and 15, the auxiliary bead is lower than the combustion chamber hole side beads 8 a and 8 b with respect to the sub-plate 3. 14 and 15 are different.

That is, with respect to the sub-plate 3, of the two flat portions of the flat portion closer to the combustion chamber hole 4a than the combustion chamber hole bead 8a and the flat portion closer to the cooling water hole 5 than the combustion chamber hole bead 8a, The seal line is expanded by molding at least one bead formed by processing the flat portion at least on the flat portion on the combustion chamber hole 4a side.
FIG. 14 shows an example in which the auxiliary bead is configured with a step-shaped half bead 14 on the flat part on the combustion chamber hole 4a side, and an example in which the auxiliary bead is configured with the full beat 15 on the flat part on the cooling water hole 5 side. . In FIG. 15, the example which formed the auxiliary bead 14 which consists of a full beat in the flat part by the side of the combustion chamber hole 4a is shown.
Other configurations are the same as those in the above embodiment.

(Function and effect)
By molding a small bead on the flat portion on the combustion chamber hole 4a side and forming a portion having a high surface pressure locally near the combustion chamber hole 4a, the high temperature and high pressure gas coming from the combustion chamber hole 4a side is double sealed. I can do it.
More specifically, the gasket fastened with the bolt 52 is the sub-plate 3 that is in contact with the cylinder block 50 at the lower portion of the cooling water hole 5 between the bolt holes 6 sandwiching the center of the combustion chamber hole 4a. The outermost part of the engine and the bead seal line part around the combustion chamber hole 4a generate a high surface pressure to deform the engine into a curve. The joint surface S of the cylinder head 51 that is curved and deformed has the largest deformation at the center of the combustion chamber hole 4a, and in the gasket portion, the flat portion on the combustion chamber hole 4a side is slightly smaller than the bead molded around the combustion chamber hole 4a. There is a gap. The deformation of the joint surface S is also promoted by the bead load. This slight gap may cause a harmful effect in the long term because an action of absorbing and discharging combustion gas and cooling water occurs due to the explosion vibration of the engine.

On the other hand, in the present invention, this slight gap is supplemented by the auxiliary beads 14 and 15 having a weak spring stress formed in the flat portion in this embodiment to prevent the combustion gas from entering the main beads.
The auxiliary beads 14 and 15 may be flat portions from the combustion chamber hole side beads 8a molded around the combustion chamber holes 4a to the flat portions on the combustion chamber hole 4a side or the water holes outside the combustion chamber hole side beads 8a, or further. Whether it is provided inside or outside the bead is determined by the rigidity of the engine. Of course, the shape and size of the auxiliary beads 14 and 15 are also determined and determined by the rigidity of the engine. However, in order to provide a change in the width of the auxiliary beads and to efficiently distribute the limited tightening load, it is along the circumferential direction. A method is also adopted in which the vicinity of the bolt is wide and the space between the bolts is narrow.

(application)
In the above embodiment, the auxiliary beads 14 and 15 are formed on the sub-plate 3, but the auxiliary beads 14 and 15 are formed on the substrate 2 side instead of the sub-plate 3 or together with the sub-plate 3. Also good. FIG. 10, which is a diagram of a portion between the combustion chamber holes 4 a, illustrates a case where the auxiliary beads 16 are formed on the substrate 2.
Moreover, all embodiment is not limited to a structure by the said embodiment. For example, the sealing material may be applied and pasted on both surfaces of the substrate 2 and the sub-plate 3 in whole or in part.
Further, a plate thickness difference may be provided between the substrate 2 and the sub plate 3 in accordance with the rigidity of the engine.
Here, when the plate thickness of the gasket is defined, the plate thickness of the sub plate 3 or the plate thickness of the substrate 2 is adjusted to match the required plate thickness. At this time, even if the plate thickness is limited, the present invention prevents the leakage of combustion gas, water, and oil by adjusting the thickened portion provided around the bolt hole and at the outer peripheral end as in the first embodiment. The optimal balance that can be configured.

It is the partially broken top view which shows the metal gasket which concerns on 1st Embodiment based on this invention. It is CC sectional drawing of FIG. It is AA sectional drawing of FIG. It is another example of AA sectional drawing of FIG. It is DD sectional drawing of FIG. It is another example of DD sectional drawing of FIG. It is a schematic diagram which shows a deformation | transformation of the joint surface. It is another example of DD sectional drawing of FIG. It is a schematic diagram which shows a deformation | transformation of the joint surface. It is another example of DD sectional drawing of FIG. It is a schematic diagram which shows a deformation | transformation of the joint surface. It is sectional drawing explaining the metal gasket which concerns on 2nd Embodiment based on this invention. It is sectional drawing explaining another metal gasket which concerns on 2nd Embodiment based on this invention. It is sectional drawing explaining the metal gasket which concerns on 3rd Embodiment based on this invention. It is sectional drawing explaining another metal gasket which concerns on 3rd Embodiment based on this invention. It is sectional drawing explaining another metal gasket which concerns on 3rd Embodiment based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal gasket 2 Board | substrate 3 Subplate 4a Combustion chamber hole 4b Combustion chamber hole 5 Cooling water hole 7 Oil hole 8a Combustion chamber hole side bead 8b Combustion chamber hole side bead 9 Outer peripheral side bead 9a Metal bead 10 Thickening part 10a Shim plate 10b Metal 11 Third bead 12 Thickened portion 12a Thin metal plate 12b Thin plates 14, 15 Auxiliary beads 16a, 16b Sealing material 50 Cylinder block 51 Cylinder head 52 Bolt S Joint surface

Claims (5)

A substrate made of an elastic metal plate capable of generating a spring, and a sub-plate having a thickness equal to or different from the thickness of the substrate and made of an elastic metal plate capable of generating a spring and disposed in opposition to a part of the substrate in the thickness direction. A board,
The substrate has a combustion chamber hole side bead formed by processing the substrate in the plate thickness direction so that the combustion chamber hole is opened and surrounds the combustion chamber hole, and is formed on the outer peripheral side of the combustion chamber hole side bead. The cooling water hole is opened and a second bead is provided so as to surround the outer periphery of the cooling water hole, and the bolt hole is opened outside the second bead,
A combustion chamber hole-side bead formed by processing the sub-plate in the thickness direction so as to surround the combustion chamber hole and also has a combustion chamber hole corresponding to the combustion chamber hole of the substrate also in the sub plate. Molded, and the outer peripheral end position of the sub-plate is set to be on the outer peripheral side with respect to the combustion chamber hole side bead forming position on the substrate and on the inner peripheral side with respect to the second bead forming position,
A thickened portion is provided for the substrate portion located outside the second bead, and the total plate thickness at the position where the thickened portion is provided is greater than the total plate thickness composed of the laminated substrate and sub-plate. A metal gasket characterized in that the height of the thickened portion is adjusted to be small.   The metal gasket according to claim 1, wherein at least a part of the thickened portion is provided around the bolt hole. The metal gasket according to claim 1 or 2, wherein at least a part of the thickened portion is provided at an outer peripheral end portion of the substrate. The bead formed outside the second bead forming position, including the second bead, is configured by any of the following (a) or (b). Item 4. The metal gasket according to any one of Items 3 to 3.
(A) A bead is comprised with the heat-resistant elastic soft sealing material fixed to both surfaces of the board | substrate.
(B) The bead is composed of a synthetic bead composed of a metal bead obtained by processing the substrate itself in the plate thickness direction and a heat-resistant elastic soft sealing material fixed to both surfaces of the metal bead.   For at least one of the substrate and the sub-plate, at least combustion of the flat part on the combustion chamber hole side from the combustion chamber hole side bead and the flat part on the cooling water hole side from the combustion chamber hole side bead. 5. A seal line is added to the flat portion on the chamber hole side by molding at least one bead lower than the combustion chamber hole side bead formed by processing the flat portion. The metal gasket according to any one of the above.

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