JP4852281B2 - gasket - Google Patents

Description

  The present invention has a function of sealing combustion gas, water pressure, oil pressure and the like by being interposed between a joint surface of a cylinder block constituting an internal combustion engine and a joint surface of a cylinder head and bolted. The present invention relates to a gasket useful as a cylinder head gasket, and particularly has a feature in the structure of a substrate between seal lines.

  Conventionally, a gasket as shown in Patent Document 1 is known as this type of gasket. That is, combustion chamber holes are formed in a substrate made of a thin metal plate, and liquid holes such as cooling water holes and oil holes and bolt holes are formed on the outer peripheral side of the combustion chamber holes. A seal line is set around the holes such as the combustion chamber hole and the liquid hole that need to be sealed, and a bead that is elastically deformed in the plate thickness direction is formed along the seal line. Further, a thickened portion having a plate thickness thicker than other portions is formed around the combustion chamber hole and on the inner peripheral side of the seal line sealing the combustion chamber hole so as to surround the combustion chamber hole. The height of the bead is set higher than that of the thickened part, and when the gasket is fastened to the joint surface between the cylinder head and the cylinder block with a bolt, the bead is compressed to the height of the thickened part by the bolt tightening load. The seal pressure is generated by elastic deformation. The thickened portion receives a bolt tightening load so as not to be excessively tightened as described above, generates an appropriate surface pressure in the seal line, and exhibits a sealing action due to the high surface pressure generated in the thickened portion.

As described above, when the gasket is fastened with bolts, the surface pressure of the seal line is lower than the surface pressure of the thickened portion provided around the combustion chamber hole. Further, a gap is generated in the plate thickness direction by the difference between the plate thickness of the thickened portion and the plate thickness of the flat substrate portion between the adjacent seal lines and the flat portion of the substrate far from the thickened portion.
When the engine is started in this state, a temperature gradient is generated from the vicinity of the combustion chamber hole toward the outer periphery at the beginning of the start. Therefore, the substrate is thermally deformed until the temperature becomes uniform, and the surroundings of the combustion chamber hole In some cases, the outer peripheral side having a lower surface pressure than the thickened portion was inclined in the plate thickness direction. When the board thickness is thick, the effect is small, but when the board thickness is thin, when the gasket is finely moved in the thrust direction during engine operation, the part near the combustion chamber hole and the part away from the combustion chamber hole Therefore, the amount of movement in the thrust direction is different, which may cause wrinkles and deformation in the flat portion of the substrate around the liquid hole where there is a gap in the plate thickness direction.

In order to solve this problem, Patent Document 1 discloses a method for preventing the occurrence of wrinkles by providing a reinforcing bead that bridges from the inner peripheral side to the outer peripheral side of the cooling water hole.
Japanese Patent Application No. 8-119263

However, in the method shown in Patent Document 1, since the reinforcing bead receives the flow of the cooling water passing through the cooling water hole, it is necessary to increase the rigidity of the base portion of the reinforcing bead where stress is particularly concentrated.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a gasket that can effectively prevent generation of wrinkles and deformation accompanying fine movement in the thrust direction.

Gasket according to claim 1 of the present invention is interposed between the joint surface facing the cylinder block and cylinder head constituting the engine, corresponding to the bore holes opening at least on the joining surface combustion chamber holes and combustion A plurality of liquid holes located on the outer peripheral side of the chamber hole are formed in a thin metal plate substrate, and the inner peripheral side of the substrate surrounds the combustion chamber hole between the combustion chamber hole and the plurality of liquid holes. A seal line is set, and an outer peripheral side seal line is set so as to surround at least a part of the combustion chamber hole and the plurality of liquid holes on the outer peripheral side of the inner peripheral side seal line, and the inner peripheral side seal line and the In the gasket in which the inner peripheral bead and the outer peripheral bead are formed along the outer peripheral seal line, the inner peripheral bead and the outer peripheral bead are connected to the substrate portion between the adjacent liquid holes. The reinforcing bead is formed, wherein the height of the reinforcing bead, characterized in that not more than equal to the height of the thickness direction of the inner peripheral side bead and the outer bead.

According to a second aspect of the present invention, the gasket according to the first aspect is characterized in that the reinforcing bead is a metal bead formed by bending the substrate portion in a plate thickness direction and molding it into a convex shape.
The gasket according to claim 3 of the present invention is the gasket according to claim 1, wherein the reinforcing bead is formed into a convex shape by bending the substrate portion in the plate thickness direction, and the convex portion of the metal bead. A rubber bead made of an elastic sealing material that is fixed to the side surface and the concave portion on the back side of the convex portion and elastically deforms in the plate thickness direction together with the metal bead is characterized in that it is composed.

According to a fourth aspect of the present invention, the gasket according to the first aspect is characterized in that the reinforcing bead is a rubber bead made of an elastic sealing material fixed to the substrate portion and elastically deformed in the plate thickness direction.
The gasket according to claim 5 of the present invention is the gasket according to claim 3 or 4, wherein a thin film is formed at least on both surfaces of the flat portion of the substrate sandwiched between the inner peripheral seal line and the outer peripheral seal line. It is characterized by.

  According to the gasket of the present invention, wrinkles and deformation can be effectively prevented, and the durability is excellent.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a gasket G according to the present embodiment. First, the configuration will be described.
The substrate 2 is made of a thin metal plate such as a stainless steel plate or a mild steel plate.
As shown in FIG. 1, a plurality of combustion chamber holes 3 arranged in the longitudinal direction are opened at a substantially central portion of the substrate 2. A hard first thickened portion formed by folding the end portion upward or downward or fixing another metal plate to the upper surface or the lower surface of the substrate 2 around the entire periphery of the edge of the combustion chamber hole 3. 7 is formed. The 1st thickening part 7 shown in FIG. 1 has illustrated the case where an edge part is folded back and formed.

An inner peripheral side seal line SL1 is arranged so as to surround the outer periphery of each combustion chamber hole 3 and the first thickened portion 7 in an endless annular shape.
Further, a cooling water hole 6, a bolt hole 4, and an oil hole 5 are opened on the outer peripheral side of the inner peripheral side seal line SL <b> 1 in the substrate 2. The plurality of cooling water holes 6 are provided at substantially equal intervals along the circumferential direction of the combustion chamber hole 3. An outer peripheral seal line SL2 is disposed along the outer peripheral side of the cooling water hole 6 so as to surround the plurality of cooling water holes 6, and a third seal line SL3 is disposed along the outer edge of the substrate. As a result, the cooling water hole 6, the bolt hole 4, and the oil hole 5 are sealed to the outer peripheral side and the third seal lines SL2 and SL3. Note that the outer peripheral side and a part of the third seal lines SL2 and SL3 are shared. In addition, arrangement | positioning of the seal line shown by this embodiment is an example.

And in this embodiment, the reinforcement bead 12 which connects these inner peripheral side and outer peripheral side seal lines SL1 and SL2 is formed in the board | substrate 2 part between the cooling water holes 6 and 6 adjacent in the circumferential direction, and several reinforcement | strengthening is carried out. The beads 12 are arranged radially from the center of the combustion chamber hole 3. This will be described in detail later.
A second thickened portion 8 is formed at a part of the outer end portion of the substrate 2, and a third thickened portion 9 is disposed so as to surround the outer periphery of each bolt hole 4.

Next, an inner peripheral side bead formed along the inner peripheral side seal line SL1, an outer peripheral side bead formed along the outer peripheral side seal line SL2, and a reinforcing bead for connecting the inner peripheral side and the outer peripheral side bead. 12 will be described.
FIG. 2 shows an example of a reinforcing bead. FIG. 4A is a cross-sectional view taken along line B-B not including the reinforcing bead 12, and FIG. 5B is a cross-sectional view taken along line A-A including the reinforcing bead 12.

  The inner peripheral side beads were formed by molding on a full bead-shaped metal bead 10 that is bent in the thickness direction so that the substrate 2 is convex toward the lower side, and the upper and lower surfaces of the metal bead 10. Elastic sealing materials 21a and 21b. The bead height of the metal bead 10 is set slightly higher than the first thickened portion 7. The elastic sealing material 21 a on the upper surface side of the metal bead 10 is filled in the concave portion on the back side of the convex portion of the metal bead 10 so as to be substantially flush with the upper surface of the substrate 2. The elastic sealing material 21 b on the lower surface side of the metal bead 10 is formed on the convex surface side of the metal bead 10 at a height that is equal to or slightly higher than the height of the metal bead 10. The height of the elastic sealing material 21b on the convex side is preferably in the range of 0.9 to 1.1 times the height of the metal bead. However, if the maximum amount of compressive deformation of the rubber bead regulated by the first thickened portion 7 is smaller than the amount that causes compression failure (for example, 40% or more) and the desired spring force can be exhibited, it is limited to the above range. Not. As the elastic sealing material, for example, a rubber material or a resin material having elasticity such as fluorine rubber, NBR, or silicone rubber is used. Moreover, in this embodiment, since the thin film of the surface of the board | substrate 2 is also formed with the same material so that it may mention later, it is preferable to use what has fluidity | liquidity and has heat resistance, oil resistance, and water resistance.

  Similar to the inner peripheral bead, the outer peripheral bead is a full bead-shaped metal bead 11 formed by bending the substrate 2 in the thickness direction so as to be convex downward, and on both upper and lower surfaces of the metal bead 11. It is composed of a combination of rubber beads made of elastic sealing materials 23a and 23b formed by molding. Since the formation state and formation height of the metal bead 11 and the elastic sealing materials 23a and 23b are the same as those of the inner peripheral bead, the details are omitted.

  As shown in FIG. 2 (a), the flat portion of the substrate 2 sandwiched between the inner peripheral bead and the outer peripheral bead that are convex downward in the plate thickness direction has thin films 25a and 25b on both the upper and lower surfaces. Covered with. In the present embodiment, the thin films 25a and 25b are made of the same material as the elastic sealing materials 23a and 23b of the rubber beads constituting the inner and outer peripheral beads. In the figure, reference numeral 13 denotes a small hole for forming the elastic sealing materials 23a and 23b, the thin films 25a and 25b and the elastic sealing material of reinforcing beads described later on both the upper and lower surfaces of the substrate 2.

  A reinforcing bead 12 including a metal bead 12a and an elastic sealing material 12b is formed between the cooling water holes 6 and 6 adjacent in the circumferential direction in the flat portion of the substrate 2 (FIG. 2B). reference). The metal bead 12a has a full bead shape formed by bending the substrate 2 in the plate thickness direction so as to be convex downward like the metal beads 10 and 11 constituting the inner and outer peripheral side beads. It is formed. This metal bead 12 a extends along the radial direction of the combustion chamber hole 3 so as to connect the convex portions of the metal beads 10 and 11. The height of the metal beads 12 a is equal to or slightly lower than the heights of the inner and outer peripheral beads and is slightly higher than the first thickened portion 7. The elastic sealing material 12b is formed by molding and is filled in the concave portion of the metal bead 12a formed on the upper surface side of the substrate 2 so as to be substantially flush with the upper surface of the substrate 2, and the convexity on the lower surface side of the substrate 2 is provided. A thin film is also formed on the surface of the part.

Next, the operation and effect of the gasket G on which the reinforcing beads 12 are formed will be described.
The gasket G is fastened to a joint surface of a cylinder head and a cylinder block (not shown) with a bolt inserted into the bolt hole 4. Due to the tightening load of the bolt, the bead and the reinforcing bead 12 formed along the seal line are compressed in the plate thickness direction and elastically deformed until the bead height becomes substantially equal to the height of the thickened portion. In this state, there is a gap of a difference δ between the flat portion of the substrate 2 sandwiched between the inner peripheral side and outer peripheral side seal lines SL1 and SL2 and the bonding surface with the plate thickness of the first thickened portion 7. Has occurred (see FIG. 2A). However, in the present embodiment, a plurality of reinforcing beads 12 are extended from the combustion chamber hole 3 side to the outer peripheral side of the substrate 2 in the flat portion, and a gap is formed between the reinforcing beads 12 and the joint surface. Rather, it receives compressive force from the joint surface. For this reason, even when a temperature gradient occurs from the vicinity of the combustion chamber hole 3 toward the outer peripheral side when the engine is started, the reinforcing bead 12 extending along the direction of the temperature gradient is pushed by the joining surface in the plate thickness direction. Since it cannot move, thermal deformation is suppressed. Therefore, even if the cylinder block and the cylinder head vibrate in the thrust direction as the engine is operated, the occurrence of wrinkles and deformation of the gasket G can be prevented. With such a reinforcing bead 12, since the bead is formed on the substrate 2 itself, it can be molded in the same manner as the bead along the seal line, and measures necessary for securing rigidity for receiving a water flow can be taken. There is no need to apply, and processing is easy.

  Further, the reinforcing bead 12 is installed so as to connect the inner peripheral side and outer peripheral side seal lines SL1 and SL2 between the adjacent cooling water holes 6 and 6, so that the cooling water passing through each cooling water hole 6 is provided. However, since it is possible to prevent the cooling effect from being lowered due to a short circuit through the gap in the thickness direction of the substrate 2, the designed cooling effect can be obtained.

  Further, when the gasket G is molded, after the metal beads constituting the inner peripheral bead, the outer peripheral bead, the reinforcing bead 12 and the like are molded on the substrate 2, the substrate 2 is arranged in the mold and can be formed between the molds. Both or one of the gaps on the upper surface side and the lower surface side of the substrate 2 is filled with an elastic sealing material and a thin film forming material. Thus, the forming material is efficiently supplied to the upper and lower surfaces by moving back and forth through the small holes 13 provided in the substrate 2. Further, it also has a function of keeping the elastic sealing material filled above and below the substrate 2 so as not to peel from the substrate 2. In the present embodiment, the concave portions of the metal beads 10, 11 constituting the inner peripheral side and outer peripheral side beads are connected by the concave portion of the reinforcing bead 12, so that the forming material passes between the beads via the concave portion of the reinforcing bead 12. It goes back and forth and is supplied efficiently to each bead. Conventionally, small holes were provided on the R surface of the metal bead along the seal line for efficient filling. However, if there are too many small holes, the manufacturing cost will increase and the durability of the gasket will increase. May deteriorate. In that respect, if the reinforcing beads 12 are provided, the efficiency at the time of filling can be improved, so that the number of small holes on the R surface can be reduced.

  In addition, as described above, a thin film is formed on the flat portion of the substrate 2 sandwiched between the inner and outer seal lines SL1 and SL2, thereby preventing oxidative corrosion of the substrate 2 due to contact with the cooling water, and durability. It is possible to improve the performance. In recent years, the use of aluminum cylinder blocks has been increasing for weight reduction. By forming a thin film on the surface of the substrate 2, the substrate 2 using a material other than aluminum such as a steel plate, the aluminum cylinder block, It is possible to prevent potential difference corrosion due to contact. Similarly, by forming the elastic sealing material 12b on the convex surface of the reinforcing bead 12, it is possible to prevent oxidation corrosion and potential difference corrosion.

The application of the present invention is not limited to the above embodiment.
For example, the reinforcing beads 12 can be formed as shown in FIGS. 3 and 4 according to the shapes of the inner and outer peripheral beads. In addition, since the material etc. which form an elastic sealing material are the same as that of the said embodiment, detailed description is abbreviate | omitted.
The gasket G in FIG. 3 is a full bead in which the metal bead 10 forming the inner peripheral side bead along the inner peripheral side seal line SL1 in the gasket shown in FIG. The metal bead 11 of the outer peripheral side bead along the seal line SL2 is a half bead formed by bending the substrate 2 in a step shape in the plate thickness direction. The half bead-shaped metal bead 11 rises obliquely toward the lower side in the plate thickness direction on the outer peripheral side from the portion where the cooling water hole 6 is formed, and the bead height is substantially the same as the full-bead-shaped metal bead 10. Further, the elastic sealing material 23b of the metal bead 11 is formed on the lower surface side of the substrate 2 at a height equal to or slightly higher than the height of the metal bead 11, and is substantially flush with the upper surface of the substrate 2 on the upper surface side. It is formed as follows.

  In the gasket G of FIG. 3, the flat portion of the substrate 2 sandwiched between the inner peripheral side and the outer peripheral side beads is covered with the thin films 25a and 25b in the same manner as in FIG. A reinforcing bead 12 including a metal bead 12a and an elastic sealing material 12b is formed between the cooling water holes 6 and 6 adjacent to each other in the circumferential direction in the flat portion (cross section taken along line AA in FIG. 1). ing. The metal bead 12a of the reinforcing bead 12 is formed in a full bead shape formed by bending the substrate 2 in the plate thickness direction so as to be convex downward like the inner peripheral side and outer peripheral side beads. And this is extended so that it may connect from the R surface of the convex part of the metal bead 10 which comprises an inner peripheral side bead to the inclined surface of the convex part of the half bead-shaped metal bead 11 which comprises an outer peripheral side bead. The height of the metal beads 12a is equal to or slightly lower than the heights of the inner and outer peripheral beads. Further, the elastic sealing material 12 b is filled in the concave portion of the metal bead 12 a formed on the upper surface side of the substrate 2 so as to be substantially flush with the upper surface of the substrate 2.

  4 is the same as the gasket shown in FIG. 1 except that the metal beads 10 and 11 on the inner and outer side beads along the inner and outer side seal lines SL1 and SL2 It is a half bead that is bent stepwise in the thickness direction. Specifically, the metal beads 10 and 11 are formed so as to rise obliquely downward in the plate thickness direction from both sides of the cooling water hole 6 formation portion to the cooling hole 6 formation portion. These two metal beads 10 and 11 have substantially the same bead height and are slightly higher than the first thickened portion 7. In addition, elastic sealing materials 21 a and 21 b are formed on both upper and lower surfaces of the metal beads 10 and 11 so as to be substantially flush with the upper surface of the substrate 2.

  In the gasket G of FIG. 4 described above, the flat portion of the substrate 2 sandwiched between the inner peripheral side and the outer peripheral side bead is covered with thin films 25a and 25b made of the same material as the elastic sealing materials 21a and 21b. And between the cooling water holes 6 and 6 adjacent in the circumferential direction in the flat part of the said board | substrate 2 (AA line cross section of FIG. 1), the reinforcement which consists of the metal bead 12a and the elastic sealing materials 12b and 12c. A bead 12 is formed. The metal bead 12a of the reinforcing bead 12 is formed in a full bead shape formed by bending the substrate 2 in the plate thickness direction so as to protrude upward in the plate thickness direction opposite to the inner peripheral side and outer peripheral side beads. . And this is extended so that it may connect from the bead surface (R surface) of the recessed part of the metal bead 10 which comprises an inner peripheral side bead to the inclined surface of the recessed part of the half bead-shaped metal bead 11 which comprises an outer peripheral side bead. Is done. The height of the metal beads 12a is equal to or slightly lower than the heights of the inner and outer peripheral beads. The elastic sealing material 12b is filled in the concave portion of the metal bead 12a formed on the lower surface side of the substrate 2, is connected to the elastic sealing materials 21b and 23b on both sides, and is substantially flush with the upper surface of the substrate 2. In FIG. 4, the elastic sealing material 12c is connected to the elastic sealing materials 21a and 23a on both sides on the convex side surface of the metal bead 12a on the upper surface side of the substrate 2, and the height is the same as the elastic sealing materials 21a and 23a. .

The above-described half bead is mainly used when the space is limited, but the effect of forming the reinforcing bead 12 is the same even when the inner peripheral side and outer peripheral side beads are formed of half beads.
The present invention can also be applied to the case where a gasket is formed by stacking a plurality of substrates as shown in FIGS.

  In the gasket G of FIG. 5, two substrates 2 and 2 made of thin metal plates are stacked one above the other, and a sub-plate 300 made of a metal plate slightly thicker than the substrate 2 is interposed between the substrates 2 and 2. Being done. A plurality of combustion chamber holes 3, cooling water holes 6, bolt holes 4 and oil holes 5 are opened in these substrates 2, 2 and sub-plate 300 as shown in FIG. 1. Further, the substrates 2 and 2 are the same as those shown in FIG. 2 with respect to the inner peripheral side and outer peripheral side beads and the reinforcing bead 12 except that thickened portions are not formed at the peripheral edges of the combustion chamber hole 3 and the cooling water hole 6. It is the substantially same board | substrate and is laminated | stacked so that the recessed part of the metal beads 10 and 11 may face the mutually opposite direction. The sub-plate 300 forms a first thickened portion 307 formed by folding the end portion around the entire edge of the combustion chamber hole 3 in place of the substrate 2, and a second thickened portion 308 is formed at the outer end portion. And the 3rd thickening part (not shown) is formed so that the outer periphery of each bolt hole 4 may be enclosed. The heights of the inner peripheral bead, the outer peripheral bead, and the reinforcing bead 12 are the same as those of the first and second thickened portions 307 and 308 and the substrate 2 when the substrates 2 and 2 are stacked vertically with the sub-plate 300 interposed therebetween. 2 is a height at which a gap in the plate thickness direction is slightly formed (a height exceeding a half of the plate thickness of the sub plate 300). For this reason, at the time of bolt fastening, the inner peripheral bead, the outer peripheral bead, and the reinforcing bead 12 are compressed and deformed to generate a necessary seal surface pressure. A surface pressure is concentrated on the first and second thickened portions 307 and 308, and a high surface pressure is generated, whereby sealing is performed. In addition, when it is difficult to bend depending on the material of the sub plate 300, the thickened portion may be formed by welding a shim plate 309 as shown in FIG.

  The gasket G in FIG. 6 is a laminate in which two substrates 2 and 2 are laminated with the sub-plate 300 interposed therebetween. The substrates 2 and 2 are substantially the same as those in FIG. 3 with respect to the inner and outer peripheral beads and the reinforcing bead 12, and are stacked vertically so that the concave portion of the metal bead faces the sub plate 300. The first and second thickened portions 7 and 8 are formed on the substrate 2 side, and the sub-plate 300 has a through hole provided at a corresponding position of the combustion chamber hole 3 and the cooling water hole 6. It has become. The inner and outer beads of the substrate 2 may both be half beads or both may be full beads.

  Further, the reinforcing bead 12 is not limited to one constituted by combining a metal bead and an elastic sealing material. For example, the reinforcing bead may be composed only of an elastic sealing material (see FIG. 8). In FIG. 8, an elastic sealing material that protrudes downward in the same thickness direction as the inner peripheral side and outer peripheral side beads is formed on the flat portion of the substrate 2 between the cooling water holes adjacent in the peripheral direction. It extends so that a side and an outer peripheral side bead may be connected. Similarly, although not shown, the reinforcing bead may be formed of only a metal bead. In addition, although not shown in the figure, instead of a metal bead or an elastic seal material, a shim plate is welded so as to connect the beads to the surface on which the inner peripheral side and outer peripheral side beads are convex. However, since the rigidity in the plate thickness direction can be increased, deformation from the combustion chamber hole side to the outer peripheral side can be prevented.

  Further, the inner peripheral side and outer peripheral side beads are not limited to those composed of a combination of a metal bead and an elastic seal material, but only from a metal bead (see FIG. 9) and only an elastic seal material (see FIG. 10). It may be configured. In FIG. 9, the inner peripheral bead, the outer peripheral bead, and the reinforcing bead are all formed of only the metal beads 10, 11, and 12 a. In FIG. 10, the inner peripheral bead, the outer peripheral bead, and the reinforcing bead are all formed of only the elastic sealing materials 100, 101, and 122. As shown in FIG. 2, when the inner peripheral side and the outer peripheral side beads are configured by combining a metal bead and an elastic sealing material, the sealing surface pressure can be adjusted by the hardness and molding width of the elastic sealing material. The hardness of the substrate can be lowered, and as a result, fatigue failure of the substrate can be prevented and the life can be extended. Furthermore, since this method is a face seal, it can seal well with a low surface pressure, and the gasket coefficient is low, so that the limited tightening load can be used effectively and the overall tightening load can be reduced. The effect of being able to do it is acquired.

  Further, the reinforcing bead 12 is not limited to the one that connects the inner peripheral side and the outer peripheral bead as long as it extends from the combustion chamber hole side toward the outer peripheral side between the liquid holes adjacent in the circumferential direction. It may be connected to only one of the beads, or may not be connected to either bead. As one connected to only one bead, for example, the outer peripheral bead is not formed in a substantially circular shape in a plan view of the gasket, but is constricted so as to extend toward the inner peripheral side between the cooling water holes 6 and 6. And an outer peripheral bead in which a reinforcing bead (neck portion) is integrally formed may be formed. However, as in the above embodiment, it is preferable to connect the inner and outer bead and to form the reinforcing bead so as to surround the cooling water hole with the bead because the entire inner bead and the outer bead can be strengthened.

  In FIG. 2 and the like, the height of the reinforcing bead 12 is slightly higher than that of the thickened portion, but it is not necessarily required to be higher than that of the thickened portion in order to obtain the effect of preventing wrinkles and deformation of the present invention. However, if it is made higher than the thickened portion, each cooling water hole 6 is sealed as described above, so that a cooling effect as designed can be obtained. However, if the reinforcing bead is too high, the surface pressure of the seal line will be higher, which will hinder the sealing action, and if the bead deformation becomes large, there is a risk of fatigue failure. The height is equal to or less than the height of the outer bead. Similarly, the present invention does not particularly limit the molding width of the reinforcing bead and the hardness of the elastic sealing material used for the reinforcing bead, but it is preferable that the tightening load and the surface pressure are not excessively increased. For example, in FIG. 2, a thin-film elastic sealing material 12b is formed on the surface of the convex portion of the reinforcing bead 12, but the elastic sealing material 12b may be formed so that the height is the same over the entire bead width. Good.

Although not shown, a small hole such as the small hole 13 of the substrate 2 may be provided on the R surface of the reinforcing bead 12. Thereby, the filling efficiency of the elastic sealing material is improved as described above, and the number of small holes formed in the inner peripheral side and the outer peripheral side beads can be reduced to prevent deterioration of durability.
Further, not only between the inner peripheral side and outer peripheral side beads, but also between the liquid holes adjacent in the circumferential direction of the combustion chamber hole 3, for example, a reinforcing bead that connects the third seal line SL3 shown in FIG. 1 is provided. May be.

It is a top view of the gasket concerning this embodiment. (A) is the sectional view on the BB line shown in FIG. 1, (b) is the sectional view on the AA line shown in FIG. (A) is the BB sectional view taken on the line which shows the gasket which concerns on the modification of this invention in FIG. 1, (b) is the AA sectional view taken on the line in FIG. (A) is the BB sectional view taken on the line which shows the gasket which concerns on the modification of this invention in FIG. 1, (b) is the AA sectional view taken on the line in FIG. (A) is the BB sectional view taken on the line which shows the gasket which concerns on the modification of this invention in FIG. 1, (b) is the AA sectional view taken on the line in FIG. (A) is the BB sectional view taken on the line which shows the gasket which concerns on the modification of this invention in FIG. 1, (b) is the AA sectional view taken on the line in FIG. It is the sectional view on the AA line shown in FIG. 1 of the gasket which concerns on the modification of this invention. It is the sectional view on the AA line shown in FIG. 1 of the gasket which concerns on the modification of this invention. (A) is the BB sectional drawing of the gasket which concerns on the modification of this invention shown in FIG. 1, (b) is the sectional view on the AA line shown in FIG. 1, (c) is (b). It is a figure which shows the example which comprised the 1st and 2nd thickening part of the gasket of this invention by adhering a shim board. (A) is the BB sectional view taken on the line which shows the gasket which concerns on the modification of this invention in FIG. 1, (b) is the AA sectional view taken on the line in FIG.

Explanation of symbols

2 Substrate, 3 Combustion chamber hole, 4 Bolt hole, 5 Oil hole, 6 Cooling water hole, 7, 7 'First thickened portion, 8, 8' Second thickened portion, 9 Third thickened portion, 10, DESCRIPTION OF SYMBOLS 11 Metal bead, 12 Reinforcement bead, 12a Metal bead, 12b Elastic sealing material, 13 Small hole, 21a, 21b Elastic sealing material, 23a, 23b Elastic sealing material, 25a, 25b Thin film, 100, 101, 122 Elastic sealing material, 300 Sub-plate, 307 first thickened portion, 308 second thickened portion, 309 shim plate, G gasket, SL1 inner peripheral side seal line, SL1 inner peripheral side seal line, SL2 outer peripheral side seal line, SL3 third seal line

Claims (5)

A combustion chamber hole corresponding to at least a bore hole that is interposed between opposed joint surfaces of a cylinder block and a cylinder head constituting the internal combustion engine, and a plurality of holes that are located on the outer peripheral side of the combustion chamber hole. A liquid hole is formed in a thin metal plate substrate,
  An inner peripheral seal line is set on the substrate so as to surround the combustion chamber hole between the combustion chamber hole and a plurality of liquid holes, and the combustion chamber hole and the outer peripheral side of the inner peripheral seal line Set an outer peripheral seal line so as to surround at least a part of the plurality of liquid holes,
  In the gasket which formed the inner periphery side bead and the outer periphery side bead respectively along the inner periphery side seal line and the outer periphery side seal line,
  Forming a reinforcing bead that connects the inner peripheral side bead and the outer peripheral side bead to the substrate portion between the adjacent liquid holes;
  The gasket according to claim 1, wherein a height of the reinforcing bead is equal to or less than a height in a plate thickness direction of the inner peripheral bead and the outer peripheral bead. 2. The gasket according to claim 1, wherein the reinforcing bead is a metal bead formed by bending the substrate portion in a plate thickness direction to form a convex shape. 3. The reinforcing bead is fixed to a metal bead formed by bending the substrate portion in the plate thickness direction and formed into a convex shape, and to the concave portion on the convex portion side surface and the convex portion rear side of the metal bead, together with the metal bead. 2. The gasket according to claim 1, wherein the gasket is composed of a rubber bead made of an elastic sealing material that elastically deforms in the thickness direction. The gasket according to claim 1, wherein the reinforcing bead is a rubber bead made of an elastic sealing material that is fixed to the substrate portion and elastically deforms in a plate thickness direction. 5. The gasket according to claim 3, wherein a thin film is formed on at least both surfaces of the flat portion of the substrate sandwiched between the inner peripheral seal line and the outer peripheral seal line.

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