JP2007120719A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket which can furthermore surely equalize the surface pressure on a thick portion. <P>SOLUTION: Bores 1 for combustion chambers are opened in the base plate of the gasket 10, and first thick portions 5 are formed so as to surround the bores 1 for combustion chambers. The first thick portions 5 are formed on the whole peripheries of the end edge of the bores 1 for combustion chambers by folding back the edge portions of the bores 1 for combustion chambers upward. The portions of the first thick portions 5 continued to the flat portions of the base plate are called lower side base plate portions 11, and the portions continued to the lower side base plate portions 11 and overlap with the lower side base plate portions 11 by being folded back are called folded-back portions 12. Recessed portions 11a are formed on the overlapping surface of the lower side base plate portions 11 so as to elongate in the circumferential direction. When a fastening load is applied to the first thick portions 5 in this state, the thickness of the lower side base plate portions 11 at the portion, where the fastening load is heavy, decreases by its deformation. As a result, the variation of the thickness is naturally caused according to the magnitude of the surface pressure, and the surface pressure can be equalized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gasket, and particularly has a feature in the structure of the thickened portion.

As a gasket interposed between a joint surface of a cylinder block constituting an internal combustion engine and a joint surface of a cylinder head, a gasket as shown in Patent Document 1 is known.
In the gasket shown in Patent Document 1, a plurality of combustion chamber holes are opened in a substrate made of a thin metal plate, and bolt holes are opened on the outer peripheral side of the combustion chamber holes. A bead and a thickened portion are formed around the combustion chamber hole. The bead is made of a member that elastically deforms in the plate thickness direction, and seals the combustion gas pressure. The thickened portion is a portion where the plate thickness is formed thicker than other portions of the substrate, and regulates the amount of compressive deformation of the bead. Further, when the gasket is fastened to the joint surface with the bolt inserted into the bolt hole, the tightening load of the bolt is concentrated on the thickened portion, resulting in a high surface pressure, thereby sealing the combustion gas pressure.

However, the tightening load by the bolt is not evenly applied to the entire thickened portion, and a greater tightening load is applied in the vicinity of the bolt tightening position than in the portion away from the tightening position. For this reason, if the plate thickness of the entire first thickened portion is formed to be the same, the surface pressure becomes non-uniform throughout the first thickened portion, thereby impairing the roundness of the combustion chamber, causing power loss and oil There is a risk of increasing consumption. On the other hand, in the gasket shown in Patent Document 1, the thickness of the thickened portion is changed between adjacent combustion chamber holes, for example, the thickness of the thickened portion is made thicker than other portions of the thickened portion. In this way, the surface pressure is made uniform.
JP-A-4-307178

However, in the method of Patent Document 1 described above, it is necessary to predict where the surface pressure is high and to change the plate thickness in advance, and thus there is a deviation from the actual surface pressure distribution.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a gasket that can more reliably equalize the surface pressure of the thickened portion.

In order to solve the above-described problems, a gasket according to claim 1 of the present invention is a gasket in which a thickened portion having a thicker thickness than other portions is formed on a substrate made of a thin metal plate, and the thickened portion is formed inside the thickened portion. The cavity is formed continuously or intermittently along the extending direction of the thickened portion.
A gasket according to a second aspect of the present invention is the gasket according to the first aspect, wherein a combustion chamber hole is opened in the substrate, and the thickening portion is formed by stacking one or more thickening plates on the substrate portion around the combustion chamber hole. Continuously along the circumferential direction of the combustion chamber hole, at least one of the one or more thickening plates and the overlapping surface of the substrate portion overlapping the thickening plate formed around the combustion chamber hole. Alternatively, the cavity is formed by intermittently forming recesses.

  The gasket according to claim 3 of the present invention is a gasket in which a thickened portion having a thicker plate thickness than other portions is formed on a substrate made of a thin metal plate, and a combustion chamber hole is opened in the substrate, and the thickened portion is formed. Is formed around the combustion chamber hole by overlapping one or more thickening plates on the substrate portion around the combustion chamber hole, and at least one of the one or more thickening plates and the substrate portion overlapping the thickening plate. A concave portion is formed continuously or intermittently along the circumferential direction of the combustion chamber hole by bending the tube in the plate thickness direction.

A gasket according to a fourth aspect of the present invention is the gasket according to the second aspect, wherein the second concave portion is formed on the back surface of the member in which the concave portion is formed, and the concave portion and the second concave portion are displaced from each other when viewed from the thickness direction. It is characterized by.
By forming the second concave portion on the back surface of the overlapped surface where the concave portion is formed as viewed from the thickness direction, the member forming the concave portion is easily crushed according to the magnitude of the load. Become.

A gasket according to a fifth aspect of the present invention is the gasket according to the second or fourth aspect, wherein the concave portion is formed in a substrate portion overlapping the thickened portion, and the portion other than the concave portion is flat on the substrate. It is characterized by projecting in the plate thickness direction from the portion.
In this way, by allowing the protrusion to protrude, the load tends to concentrate on a portion other than the concave portion, and when the load is applied, the protruding portion has less meat than the case where the concave portion is formed in the flat portion without protruding. Since it becomes easy to escape to the concave portion, the portion of the substrate that overlaps with the thickened portion is easily crushed according to the magnitude of the load.

  A gasket according to a sixth aspect of the present invention is the gasket according to any one of the second to fifth aspects, wherein the thickening plate is constituted by the thin metal plate continuous to the substrate, and the thin metal plate is disposed around the combustion chamber hole. The thickened portion is formed by folding and overlapping the substrate.

  According to the present invention, the surface pressure of the thickened portion can be made uniform.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a gasket 10 of the present embodiment. First, the configuration will be described.
The gasket 10 of this embodiment is an example of a gasket interposed between the joint surfaces of the cylinder head and the cylinder block of the internal combustion engine. The gasket 10 uses a thin metal plate as a substrate. Examples of the thin metal plate include a thin stainless steel plate, a mild steel plate, and an aluminum plate. In this embodiment, a mild steel plate is used to provide an inexpensive gasket.

As shown in FIG. 1, a combustion chamber hole 1, a coolant hole 4, a bolt hole 2, and an oil hole 3 are opened in the substrate.
A plurality of combustion chamber holes 1 are formed in a substantially central portion of the substrate in the longitudinal direction, and are opened at the joint surface of the internal combustion engine at positions corresponding to combustion chambers (bore) that explode a plurality of combustion gases. Is formed.

  A plurality of cooling liquid holes 4 are opened along the outer periphery of the combustion chamber hole 1 at positions corresponding to the cooling liquid holes opened in the joint surface. Moreover, the bolt hole 2 is formed corresponding to the position where the bolt which fastens and fixes the gasket 10 to the cylinder block and the cylinder head is inserted. Similarly, the oil hole 3 is close to the bolt hole 2 and opens closer to the outer peripheral side of the substrate than the bolt hole 2 corresponding to a predetermined position necessary for passing the lubricating oil.

Around the holes, first to third seal lines SL1 to SL3 are set to prevent combustion gas, cooling liquid, lubricating oil, and the like passing through the holes from leaking between the joint surfaces.
The first seal line SL1 is set in an endless annular shape so as to surround the outer periphery of a first thickened portion 5 (described later) formed around the combustion chamber hole 1. In addition, between the adjacent combustion chamber holes 1 and 1, the respective first seal lines SL1 and SL1 merge and are integrated into one seal line.

The second seal line SL2 is set so as to surround the plurality of coolant holes 4 as one continuous region along the outer peripheral side of the coolant holes 4.
The third seal line SL3 is set so as to surround the oil hole 3 and the bolt hole 2 formed close to the oil hole 3. The third seal line SL3 is arranged on the outer peripheral side of the second seal line SL2, and merges with the second seal line SL2 at a portion where the coolant hole 4 and the bolt hole 2 are close to each other. Integrated into the seal line.

Beads are formed along the first to third seal lines SL1 to SL3, respectively.
As shown in FIG. 2, the bead is composed of a combination of a metal bead a and elastic sealing materials b and c.
The metal bead a is formed by bending the substrate so as to be convex toward one side in the plate thickness direction. The shape of the metal bead a is not limited in the present invention, and various shapes can be adopted. However, what is shown on the cut surface in FIG. 2 is an arch-shaped full bead. The bead height of the metal bead a is set to be higher than the thickened portion (described later), and the necessary seal is obtained by elastically deforming up to the gap height in the plate thickness direction formed by the thickened portion. Pressure can be generated.

  The elastic sealing materials b and c are formed by molding in the concave portions on the convex surface side and the convex rear surface side of the metal bead a, and elastically deform with the metal bead a in the plate thickness direction to generate a necessary sealing pressure. As the material of the elastic sealing materials b and c, for example, a rubber material or a resin material having elasticity such as fluorine rubber, NBR, silicone rubber or the like can be used, which has fluidity and heat resistance, oil resistance, and water resistance. What it has can be used suitably.

  Explaining a specific shape, the elastic sealing material b is formed on the convex surface side substantially parallel to the flat surface of the substrate, and the height thereof is substantially equal to the height of the full bead. In addition, the concave side is filled with an elastic sealing material c so as to be substantially the same as the flat surface of the substrate. In addition, the height of the metal bead a is preferably in the range of 1.1 to 1.3 times the height of the first thickened portion 5. However, if the maximum amount of compressive deformation of the rubber bead regulated by the first thickened portion 5 is smaller than the amount causing compression failure (for example, 40% or more) and the desired spring force can be exerted, it is limited to the above range. Not. The elastic sealing materials b and c are formed along the metal bead a with a width wider than that of the metal bead a.

Returning to FIG. 1, first to third thickened portions 5, 6, and 7 having a plate thickness larger than that of other portions are formed on the substrate.
The first thickened portion 5 is formed around the entire edge of the combustion chamber hole 1 by folding the end of the combustion chamber hole 1 upward. That is, the annular folded portion 12 folded upward is equivalent to the thickening plate of the present invention, and the first thickened portion 5 is formed together with the annular lower substrate portion 11 on which the folded portion 12 is overlapped. is doing. The first thickened portion 5 regulates the amount of compressive deformation of the bead of the first seal line SL1 formed along the first thickened portion 5, and seals the combustion gas pressure by the surface pressure generated between the first thickened portion 5 and the joint surface.

  The structure of the first thickened portion 5 is a characteristic part of the present invention and will be specifically described. In the present embodiment, the folded portion 12 is flat on both the upper and lower surfaces. However, the lower substrate portion 11 has a groove-like recess 11a extending in the circumferential direction on the upper and lower surfaces by applying a mold. A plurality are formed at intervals, and the cross section along the width direction has an uneven shape (wave shape). In addition, the concave portion 11a is formed alternately with the upper surface and the lower surface from the inner peripheral side to the outer peripheral side of the lower substrate portion 11, that is, shifted from the plate thickness direction. Instead of the concave portion 11 a, the convex portion 11 b is in contact with the joining surface or the overlapping surface of the folded portions 12. The convex portion 11b on the upper surface side that overlaps the folded portion 12 of the lower substrate portion 11 protrudes from the flat portion of the substrate other than the first thickened portion 5 by the depth of the concave portion 11a formed on the back surface. Is formed.

The second thickened portion 6 is formed around the entire edge of the bolt hole 2 by folding the end of the bolt hole 2 upward. Thereby, the amount of compressive deformation of the bead formed between the other thickened portions 5 and 7 or the other thickened portion 6 is restricted. Although not shown, the second thickened portion 6 is formed by folding back the upper and lower surfaces of the substrate.
The third thickened portion 7 is formed at the outer peripheral end of the substrate farthest from the outer peripheral bore center of the third seal line SL3 around the oil hole 3 by folding the outer peripheral end upward. Thereby, the amount of compressive deformation of the bead of the third seal line SL3 formed between the second thickened portion 6 and the third thickened portion 7 is regulated. The third thickened portion 7 is also formed by folding back the upper and lower surfaces of the substrate in the same manner as the second thickened portion 6.

  The three types of thickened portions are formed so as to satisfy the relationship of the thickness of the first thickened portion ≧ the thickness of the third thickened portion> the thickness of the second thickened portion. In order to obtain a plate thickness having such a relationship, for example, the second and third thickened portions 6 and 7 are thinned by plastic working such as forging or pressing after the substrate is folded. Further, the thickened portions 5, 6, 7 and the bead are formed so that the bead is higher than the height in the thickness direction gap formed by the thickened portion as described above.

Next, the operation and effect of the present invention will be described.
The gasket 10 having the above-described configuration is mounted by being tightened with a tightening bolt penetrating the bolt hole 2 between the joint surface of the cylinder block constituting the engine and the joint surface of the cylinder head.
At this time, most of the bolt tightening load is received by the thickened portions 5, 6, and 7. Among them, the first thickened portion 5 having the largest plate thickness concentrates the tightening load and has the highest surface pressure among the seal portions. Due to this tightening load, the lower substrate portion 11 of the first thickened portion 5 is sandwiched between the lower joint surface and the upper folded portion 12, thereby applying a compressive force in the plate thickness direction to flatten the uneven shape. receive. At this time, the convex portion 11b in contact with the joint surface or the folded portion 12 has a smaller contact area than when flattened, and thus the surface pressure is concentrated. Since the convex part 11b which contact | connects a joining surface and a superimposition surface is formed in the back surface side, it has a structure which is easy to be crushed flatly by being pressed in a different position from both surface sides. Further, the protrusion 11b formed on the upper surface side protrudes more in the plate thickness direction than the flat part of the substrate, so that the load is easily applied to the protrusion 11b, and when the load is applied to the flat end portion of the substrate. Compared with the case where the concave portions are continuously formed, the flesh of the convex portion 11b has a structure in which it can easily escape to the concave portion 11a, and thus is easily crushed. On the other hand, the folded portion 12 is sandwiched between the upper bonding surface and the lower lower substrate portion 11, and the portion facing the concave portion 11 a of the lower substrate portion 11 is a gap in the plate thickness direction (cavity) between the concave portion 11 a. ) To be submerged.

As described above, the folded portion 12 and the lower substrate portion 11 are deformed by the tightening load, thereby reducing the thickness direction gap formed between the joint surface and the folded portion 12 and the concave portion 11b of the lower substrate portion 11. The thickness of the first thickened portion 5 is also reduced from the initial thickness T ₀ (when the tightening load is 0) by the reduced amount T ₁ . The degree of this deformation depends on the level of the surface pressure at the portion where the deformation occurs, the deformation is large at the portion where the surface pressure is large, and the deformation is so large that the lower substrate portion 11 is completely flat at the maximum. On the other hand, the deformation is small at the portion where the surface pressure is small, and the uneven shape of the lower substrate portion 11 is slightly bent. As a result, the plate thickness becomes a thickness corresponding to the size of the surface pressure in each part, the plate thickness is thinner as the surface pressure is larger, and the plate thickness direction gap thickness formed in the recess 11a is thinner at the maximum.

  As described above, in the first thickened portion 5, the vicinity of the bolt hole 2, which is generally a tightening position, is more surface than the portion away from the bolt hole 2 (for example, between the adjacent combustion chamber holes 1, 1). Since the pressure increases, the plate thickness is also thin in the vicinity of the bolt hole 2 and thicker in the portion away from the bolt hole 2, and the plate thickness is naturally uplifted (changed) according to the surface pressure when tightened. appear. As described above, when the plate thickness of the first thickened portion 5 is reduced, the tightening load is concentrated on the thicker portion, so the load received at the thin portion is reduced, and the first thickened portion is reduced. The surface pressure of 5 is equal regardless of the vicinity of the bolt hole 2 and the portion further away from it. By equalizing the surface pressure in this way, the roundness of the combustion chamber can be improved, and power loss and oil consumption increase due to the loss of the roundness of the combustion chamber can be prevented. In addition, it is possible to prevent the occurrence of depression of the joint surface due to excessive increase in the partial surface pressure. That is, as compared with the conventional method in which a portion where the surface pressure is increased is predicted and the portion is thinned in advance, in the present embodiment, the surface pressure of the entire first thickened portion 5 is increased as described above. Accordingly, processing is performed so as to reduce the plate thickness, and the inflection is naturally caused by the actual load, so that the surface pressure can be equalized more reliably.

As described above, the first thickened portion 5 receives the maximum tightening load and sufficiently seals the explosion combustion pressure in the combustion chamber having the highest seal pressure by the uniform high surface pressure generated at this time.
Similarly, the other thickened portions 6 and 7 receive a tightening load smaller than that of the first thickened portion 5. At this time, the bead formed along each of the seal lines SL1, SL2, and SL3 compresses and deforms the elastic sealing material and the metal bead to the height of the gap in the plate thickness direction formed by the thickened portion, and the elastic repulsive force A predetermined seal pressure is generated in the seal.

  Further, the height of each thickened portion is set in the relationship of the plate thickness of the first thickened portion ≧ the plate thickness of the third thickened portion> the plate thickness of the second thickened portion as described above. The thickness of the thickened portion 7 is larger than the second thickened thickness 6. For this reason, the load received by the third thickened portion 7 is relatively large, and the outer peripheral side portion of the joining surface is pushed slightly by the third thickening portion 7 in a direction in which the joint surface opens. By opening the mouth in this way in advance, even if there is a difference in thermal expansion between the combustion chamber and the outer periphery of the engine immediately after starting the engine, it is possible to prevent further opening between the joint surfaces. Seal deterioration can be suppressed.

Although the embodiment has been described above, the application of the present invention is not limited to this.
For example, the first thickened portion 5 is not limited to the one in which the concave portions 11a are continuously formed in the circumferential direction as shown in FIG. 2, but the concave portions 11a are intermittently formed in the circumferential direction as shown in FIG. May be. The first thickened portion 5 in FIG. 3 is formed by molding using an annular mold, and an annular concave portion 11a is circumferentially formed on the upper and lower surfaces of the lower substrate portion 11 in a plan view. A plurality are formed along. The recess 11a is formed such that the center of the ring is displaced from the upper and lower surfaces when viewed from the thickness direction. For this reason, in some cases, a columnar convex portion 11b is formed on the back surface of the concave portion 11a so as to be in contact with the bonding surface or the overlapping surface on the rear surface side. Thus, another convex portion 11b in contact with the joint surface or the like is formed around the concave portion 11a so that the lower substrate portion 11 is easily crushed. When a tightening load is applied in this state, the lower substrate portion 11 itself is deformed and the meat escapes into the recess 11a, and the folded portion 12 is deformed so as to sink into the recess 11a. By these deformations, the plate thickness of the first thickened portion 5 is reduced where the tightening load is large, so that the surface pressure can be equalized and the roundness of the combustion chamber can be ensured. In addition, when it forms like FIG. 2, it will become easy to collapse according to the magnitude | size of surface pressure.

  Further, the present invention is not limited to the case where the concave portions are formed on the upper and lower surfaces of the lower substrate portion 11, and the concave portions are formed only on the upper surface of the lower substrate portion 11, that is, the overlapping surface with the folded portion 12 as shown in FIG. May be formed. The first thickened portion 5 in FIG. 4 is formed by molding using a convex shape having a rhomboid quadrangular pyramid shape on the bottom surface, and the bottom surface on the upper surface of the lower substrate portion 11 and the folded portion 12 side. A plurality of so-called inverted square pyramid-shaped concave portions 11a are formed in the width direction and the circumferential direction. When a tightening load is applied in this state, the convex portion 11b of the lower substrate portion in contact with the folded-back portion 12 is deformed so as to fall down in the gap in the thickness direction by being pushed by the folded-back portion 12, and the folded-back portion 12 also has a plate thickness. Deforms to sink into the direction gap. By these deformations, the plate thickness of the first thickened portion 5 is reduced where the tightening load is large, so that the surface pressure can be equalized and the roundness of the combustion chamber can be ensured. In addition, when forming a recessed part in this way, the plate | board thickness between the recessed part 11a and the folding | turning part 12 ensures the position which the convex part 11b of the lower board | substrate part 11 escapes, and it becomes easy to collapse the convex part 11b. It is preferable to form the directional gap larger than in the case of FIGS. In this regard, as shown in FIG. 4, it is preferable to use an inverted quadrangular pyramid shape because a larger gap in the thickness direction is formed closer to the overlapping portion.

  Furthermore, the present invention is not limited to the case where the gap in the plate thickness direction formed between the concave portion and the joint surface or the overlapping surface opposite to this is a gap, but as shown in FIG. An elastic body may be filled. In the first thickened portion 5 of FIG. 5, a plurality of groove-like concave portions 11 a that are continuous in the circumferential direction are formed on both upper and lower surfaces of the lower substrate portion 11. Further, the concave portion 11a formed on the outer peripheral side of the lower surface is connected to the concave portion of the metal bead a. Therefore, the elastic sealing material c filled in the concave portion of the metal bead a is a concave portion on the lower surface of the lower substrate portion 11. 11a is also filled. Thereby, since the lower surface of the lower substrate portion 11 becomes smooth, it is possible to prevent the surface pressure from being concentrated on a part of the unevenness when contacting the bonding surface, and the sealing action of the first thickened portion 5 is improved. .

Further, in the above example, the concave portion 11a is formed in a part of the first thickened portion 5 in the width direction, but the concave portion 11a may be formed to have the same width as the first thickened portion 5 ( Not shown). In this case, the recesses are intermittently formed in the circumferential direction so that the cross section along the circumferential direction is uneven (wavy).
Also, the case where the unevenness is formed on the lower substrate portion 11 has been described, but instead of forming the same unevenness on the folded portion 12 (that is, the thickening plate) on the lower substrate portion 11 or You may form together with forming in the lower substrate part 11.

  Further, only the case where the first thickened portion 5 is formed by folding is described. For example, the first thickened portion 5 is formed by mounting the grommet so as to sandwich the substrate end portion around the periphery of the combustion chamber hole 1. May be. In this case, the grommet corresponds to the thickening plate of the present invention, and a recess is formed on at least one of the overlapping surfaces of the grommet and the substrate. Further, for example, when the gasket 10 is formed by laminating the substrates 10 ′ and 10 ′ and the sub-plate 13 as shown in FIG. 7, the upper and lower sides of the folded portion 13 a of the sub-plate 13 constituting the first thickening portion 5. A concave portion 11a is formed on both surfaces (see FIG. 11A), or a concave portion 11a is formed on one of the overlapping surfaces of the folded portion 13a (see FIG. 10B).

Moreover, as shown in FIGS. 2-5, it is not restricted to the gasket 10 which formed the metal bead and the elastic sealing material along the seal line, but the gasket which formed only the metal bead along the seal line as shown in FIG. The present invention can be applied to 10.
Moreover, although the recessed part 11a is formed over the circumferential direction periphery in said example, you may form continuously or intermittently in a part of circumferential direction. In addition, in the case of FIG. 3 and FIG. 4, the concave portions 11a are formed at the same circumferential interval on the entire circumference of the first thickened portion. However, the present invention is not limited to this, and a portion that is expected to have a particularly high surface pressure. Concave portions 11a may be arranged at a dense interval around the periphery.

In the above embodiment, the thickness of the thickened portion is set to the relationship of the thickness of the first thickened portion ≧ the thickness of the third thickened portion> the thickness of the second thickened portion. Of course, for example, the thickness of the first thickened portion> the thickness of the second thickened portion ≧ the thickness of the third thickened portion may be satisfied.
Furthermore, in the above embodiment, the present invention is applied only to the first thickened portion 5, but the present invention may be applied to the second thickened portion 6 formed on the periphery of the bolt hole 2. For example, when the thickened portion is formed so that the thickness of the first thickened portion> the thickness of the second thickened portion ≧ the thickness of the third thickened portion as described above, the bonding surface is the first By slightly tilting in the plate thickness direction from the thickened portion 5 to the second thickened portion 6, the load received on the substrate outer peripheral side (side away from the combustion chamber) of the second thickened portion 7 is the combustion chamber hole. It becomes larger than 1 side. Therefore, by applying the present invention, the plate thickness on the side far from the combustion chamber hole 1 becomes thin, the surface pressure is equalized, and it is possible to prevent the outer peripheral joint surface from being depressed relatively. .

Moreover, in the said embodiment, although it formed by making a recessed part thinner than another part, it is not limited to this, For example, either the board | substrate part which overlaps with a thickening board or a thickening board, or both A concave portion may be formed in the bent member by bending in the plate thickness direction. Examples of gaskets having such recesses are shown in FIGS. 6 and 7C and 7D.
In the gasket 10 of FIG. 6, a bent portion 14 formed by bending the lower substrate portion 11 and the folded portion 12 so as to be convex upward in the plate thickness direction is continuously formed along the circumferential direction. A concave portion 14 a is formed on the surface of the lower substrate portion 11 in contact with the surface, and a convex portion 14 b is formed on the upper surface of the folded portion 12. The bent portion 14 is deformed by a load in the plate thickness direction and has a height corresponding to the surface pressure. As a result, the first thickened portion 5 is naturally inflated according to the surface pressure.

  7 (c) and 7 (d), the bent portion 15 formed by bending the substrates 10 'and 10' so as to be convex toward the sub-plate 13 is continuously formed in the circumferential direction. A convex portion 15a is formed on the surface of the substrates 10 'and 10' facing the sub-plate 13, and a concave portion 15b is formed on the surface facing the bonding surface. FIG. 2C shows a case where two bent portions 15 are formed, and the case where the first thickened portion 5 is wide can be dealt with. Similarly, these bent portions 15 are also deformed by a load in the plate thickness direction and have a height corresponding to the surface pressure, so that the first thickened portion 5 is naturally inflated according to the surface pressure.

It is a top view which shows the gasket of this embodiment. It is a figure which shows the paper surface left side half of the AA cross section of FIG. It is sectional drawing which shows the other gasket which concerns on this invention (a part of AA line cross section of FIG. 1). It is sectional drawing which shows the other gasket which concerns on this invention (a part of AA line cross section of FIG. 1). It is sectional drawing which shows the other gasket which concerns on this invention (a part of AA line cross section of FIG. 1). It is sectional drawing which shows the other gasket which concerns on this invention (a part of AA line cross section of FIG. 1). (A)-(d) demonstrates the case where this invention is applied to a lamination type gasket.

Explanation of symbols

1 Combustion chamber hole, 2 bolt hole, 3 oil hole, 4 coolant hole, 10 gasket, 10 'substrate, 11 lower substrate portion, 11a recessed portion, 11b protruding portion, 12 folded portion, 13a sub-plate, 14, 15 bent Part, 14a, 15a concave part, 14b, 15b convex part, a metal bead, b, c elastic sealing material

Claims (6)

In a gasket formed with a thickened part thicker than other parts on a substrate made of a thin metal plate,
A gasket having a cavity formed continuously or intermittently along the extending direction of the thickened portion in the thickened portion. A combustion chamber hole is opened in the substrate;
The thickening portion is formed around the combustion chamber hole by overlapping one or more thickening plates on the substrate portion around the combustion chamber hole,
A recess is formed continuously or intermittently along the circumferential direction of the combustion chamber hole in at least one of the one or more thickening plates and the overlapping surface of the overlapping substrate portions of the thickening plate. The gasket according to claim 1, wherein the cavity is formed. In a gasket formed with a thickened part thicker than other parts on a substrate made of a thin metal plate,
A combustion chamber hole is opened in the substrate;
The thickening portion is formed around the combustion chamber hole by overlapping one or more thickening plates on the substrate portion around the combustion chamber hole,
By bending at least one of the one or more thickening plates and the substrate portion overlapping the thickening plate in the plate thickness direction, the concave portions are continuously or intermittently formed along the circumferential direction of the combustion chamber hole. The gasket according to claim 1, wherein the gasket is formed. Forming a second recess on the back surface of the member having the recess;
The gasket according to claim 2, wherein the concave portion and the second concave portion are displaced from each other when viewed from the thickness direction.   The concave portion is formed in a substrate portion that overlaps the thickened portion, and the substrate portion is formed such that a portion other than the concave portion protrudes in a plate thickness direction from a flat portion of the substrate. The gasket according to claim 2 or 4. The thickening plate is composed of the thin metal plate continuous with the substrate,
The gasket according to any one of claims 2 to 5, wherein the thickened portion is formed by folding the thin metal plate around the combustion chamber hole and overlapping the substrate.

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