JP2005214361A - Metallic gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic gasket, coping with a small sealing width. <P>SOLUTION: In this metallic gasket, a full bead is formed on a base plate 2 along a seal line in the periphery of a combustion chamber hole 5, and a sub-plate is stacked on the base plate 2 from the recessed part side of the bead 8. The sub-plate 3 is provided with a stopper 9 projected toward the recessed part of the bead 2 to regulate the compression deformation amount in the direction of board thickness of the bead. The stopper 9 is out of contact with the bead 2 in no-load state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a metal gasket suitable as a cylinder head gasket interposed between a cylinder block and a cylinder head of an internal combustion engine.

Conventionally, as this type of metal gasket, for example, there is a metal gasket as described in Patent Document 1.
That is, in the substrate constituting the metal gasket, the combustion chamber hole is opened at a position corresponding to the bore, and a bead is formed along the seal line surrounding the combustion chamber hole. Furthermore, a stopper made of a thickened portion is formed on the substrate portion closer to the combustion chamber hole than the bead. By this stopper, the amount of compressive deformation of the bead in the plate thickness direction is regulated to prevent full bending of the bead and fatigue failure due to vibration amplitude during engine operation.

The stopper is formed by joining a shim to the combustion chamber side flat portion of the substrate to increase the thickness, or folding the combustion chamber side end portion to increase the thickness.
Further, when a plurality of substrates and sub-plates are stacked, combustion chamber holes, water holes, oil holes, bolt holes, and the like are opened at the same position for each substrate and sub-plate.
Japanese Patent Laid-Open No. 11-247998

In recent years, the diameter of the combustion chamber hole is sometimes increased with an increase in the bore diameter for increasing the displacement without changing the basic design of the engine. Engines tend to be smaller, lighter, and higher performance. For this reason, when the diameter of each combustion chamber hole is increased, a stopper for protecting the bead is arranged along with the bead in a portion having a narrow seal width such as between the combustion chamber holes or between the combustion chamber hole and the water hole. It becomes difficult to provide.
In addition, in order to prevent bead fatigue failure without providing a stopper, conventionally, it has been dealt with by increasing the number of substrates and sub-plates to be laminated. However, this method is costly. Or the number of layers increases and there is a disadvantage that the opportunity for pressure leakage increases.

In Japanese Utility Model Publication No. 4-17883, an example is provided in which a wide, trapezoidal first bead is provided, and a second bead is provided from a full bead protruding on the same side as the first bead with respect to the lower metal plate. However, this second bead exhibits spring force and reinforces the spring of the surface pressure insufficient portion of the first bead, and does not constitute a stopper as used in the present invention. This is because, for example, as described in the sixth column, lines 33 to 36, the second bead compensates the surface pressure of the surface pressure deficient portion generated in the center portion of the first bead, and the rising portion of the first bead (first It can be seen from the point that a strong surface pressure is generated on the portion that is not directly reinforced with two beads, and the fact that the amount of compressive deformation of the bead is adjusted by providing a separate stopper as shown in FIG.
The present invention has been made paying attention to the above points, and an object of the present invention is to provide a metal gasket that can cope with a narrow seal width.

In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention uses a thin metal plate as a substrate, and the substrate is bent in the plate thickness direction along a preset seal line. A metal gasket formed with a convex bead that is formed and exhibits a spring in the plate thickness direction,
Provided with a sub-plate laminated on the substrate from the concave side of the bead, and provided with a highly rigid stopper that protrudes into the concave portion of the bead with respect to the sub-plate and restricts the amount of compressive deformation in the plate thickness direction of the bead. It is characterized by that.

Next, the invention described in claim 2 is characterized in that, in the configuration described in claim 1, the stopper is formed continuously along the seal line.
Next, the invention described in claim 3 is the configuration described in claim 1, wherein the stopper includes a plurality of protrusions arranged along the seal line and projecting into the bead recess. It is characterized by.

Next, the invention described in claim 4 is characterized in that the top of the stopper is flat with respect to the structure described in any one of claims 1 to 3. .
Next, in the invention described in claim 5, in the configuration described in any one of claims 1 to 4, the stopper has a portion of the sub-plate facing the bead in the bead recess. The stopper is set to have a height and a width that are not in contact with the concave surface of the bead in an unloaded state and has a meander or width along the extending direction. By changing, the rigidity in the plate thickness direction is enhanced.

Next, in the invention described in claim 6, in contrast to the structure described in any one of claims 1 to 4, the stopper has a hole formed by a burring in a portion of the sub-plate facing the bead. The burr rising up by the burring is forged and compressed to a set height by curling and turning flat.
Next, the invention described in claim 7 is the structure described in claim 1, wherein the stopper extends continuously or intermittently along the seal line and protrudes toward the bead and has a flat top as the stopper. The stopper body is provided with a rigid improvement part that protrudes or is recessed in a direction opposite to the protruding direction of the stopper body with respect to the flat top portion of the stopper body continuously or intermittently along the extending direction of the stopper body. It is characterized in that it is formed.

  Next, the invention described in claim 8 is the configuration described in any one of claims 1 to 7, wherein at least a combustion chamber hole is opened in the substrate, and the seal line is formed in the combustion line. A seal line that surrounds the chamber hole and seals the combustion chamber hole, and at least one of the substrate and the sub-plate has a water hole at an outer peripheral side of the seal line, and the other of the substrate and the sub-plate. The outer peripheral edge position is the position of the water hole or the combustion chamber hole side from it.

  When the present invention is adopted, a stopper that protects the bead is formed at a position overlapping with the bead in plan view, so that sealing is possible even in a narrow seal width, and the amount of compressive deformation of the bead is restricted by the stopper. As a result of reducing the amplitude of the bead, for example, even if it is adopted as a seal around the combustion chamber hole, it is possible to exert a high surface pressure on the bead and seal the outer periphery of the combustion chamber hole with a high surface pressure. It becomes.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a principal part showing a metal gasket 1 according to the present embodiment. The metal gasket 1 is composed of a substrate 2 and a sub-plate 3 and is interposed between facing surfaces of a cylinder block and a cylinder head which are not shown.
The configuration will be described. As shown in FIG. 1, the substrate 2 is laminated on the sub-plate 3, and a plurality of combustion chamber holes 5 extend along the longitudinal direction in the substantially central portion of the sub-plate 3 and the substrate 2. Open side by side. Further, an inner peripheral seal line SL1 is set so as to surround each combustion chamber hole 5 respectively. In a position where the seal width between the combustion chamber holes 5 is narrow, the adjacent inner peripheral side seal lines SL1 merge to share one line.

  The size of the sub-plate 3 is substantially the same as the joining surface of the cylinder block and the cylinder head. A plurality of water holes 6 are formed in the sub-plate 3 so as to surround the combustion chamber holes 5 on the outer peripheral side of the inner peripheral seal line SL1, and further, bolt holes are provided on the outer peripheral side of the positions where the water holes 6 are arranged. 7 is open. Further, another seal line SL2 is set along the outer periphery of the bolt hole 7 and the sub plate 3.

In addition, the size of the substrate 2 is such that the outer peripheral edge 2a is on the inner side (combustion chamber hole 5 side) than the outer side of each water hole 6 provided in the sub-plate 3 as shown in FIG. 6 is designed to be located outside the inner side of 6 (combustion chamber hole 5 side). The outer peripheral edge of the substrate 2 may be on the inner side (combustion chamber hole 5 side) than the inner position of the water hole 6.
A bead 8 is formed on the substrate 2 along the inner circumferential seal line SL1. As shown in FIGS. 2 and 3, the bead 8 is a full bead formed by bending the substrate 2 in the plate thickness direction so as to protrude upward, and is compressed and deformed in the plate thickness direction to form a spring. Demonstrate.

  The sub-plate 3 is formed with a plurality of stopper projections 9 at positions facing the concave surface (lower surface) of the full bead 8. As shown in FIG. 4, the plurality of stopper protrusions 9 are formed along the inner circumferential seal line SL <b> 1 and have a size that fits within the seal width SH. The stopper protrusions 9 may be changed in width and protrusion height as appropriate according to the bead width or the like, or the interval between the stopper protrusions 9 may be changed. Each of the stopper projections 9 is formed by bending the sub-plate 3 so as to protrude upward, and the top portion 9a is set to be flat to increase the rigidity in the plate thickness direction, and the bead. The contact surface with 8 is enlarged. Here, as shown in FIG. 2 and FIG. 3, the stopper projection 9 is configured such that the protruding height is set lower than the inner surface of the full bead 8 and the width is set smaller than the full bead 8. 8 is in a non-contact state, and when the bead 8 is compressed and deformed, the concave portion of the bead 8 comes into contact with the stopper projection 9 so that the amount of compressive deformation of the bead 8 and the amplitude with respect to vibration are increased. Be regulated.

Here, the stopper projection 9 constituting the stopper is set to have high rigidity in the thickness direction. The same applies to the following stoppers.
The sub-plate 3 is formed with a bead such as a half bead or a full bead (not shown) around the bolt hole 7 or at another seal line position SL2 along the outer periphery of the sub-plate 3.

Next, functions and effects of the metal gasket 1 of the present embodiment will be described.
The bead 8 is elastically deformed in the plate thickness direction with a predetermined surface pressure by being disposed between the opposing joint surfaces of the cylinder block and the cylinder head and tightening with a tightening bolt (not shown) inserted into the bolt hole 7. Seal along the seal line. At this time, the stopper protrusion 9 arranged in the bead 8 serves as a stopper in the plate thickness direction with respect to the bead 8, and the elastic deformation amount of the bead 8 is restricted within a range not to be subjected to compressive failure. It becomes possible to seal with higher surface pressure than. That is, even if the seal surface width is narrow, the outer periphery of the combustion chamber hole 5 can be sealed with a high surface pressure.

Further, the tightening surface pressure along the seal line can be made uniform by adjusting the width, height, interval, and the like of the stopper protrusions 9 disposed in the beads 8.
Further, by limiting the position of the substrate 2 on which the beads 8 are formed with respect to the sub-plate 3 to the vicinity of the combustion chamber hole 5, that is, by increasing only the plate thickness in the vicinity of the combustion chamber hole 5, The tightening load on the bead 8 along the side seal line SL1 is further increased, and accordingly, the seal pressure around the combustion chamber hole 5 can be effectively increased. In addition, the board | substrate 2 side may be made into the dimension substantially the same as a joining surface, and the magnitude | size of the subplate 3 may be made small within the outer peripheral position of a water hole.

  Here, in the said embodiment, although the stopper provided in the subplate 3 was comprised with the some protrusion 9 located in a line along a seal line, it is not limited to this. For example, as shown in FIG. 5, a bead 10 bent into a full bead shape so as to protrude upward is used as a stopper, but the stopper is obtained by continuously changing the width along the seal line SL1 as shown in FIG. The required rigidity is secured. The rigidity required as a stopper varies depending on the tightening load.

Alternatively, as shown in FIG. 7, the bead 10 extends in a meandering manner along the seal line to ensure rigidity and serve as a stopper. 8 and 9 show a modified example of the stopper.
Note that the top of the stopper is preferably flat. By flattening, the rigidity increases and the deformation amount of the elastically deformed bead 8 can be regulated stably.
Further, when forming the stopper by molding the sub-plate 3, as shown in FIG. 10, the protrusion 11 on which the step portion 11a (the portion that rises substantially vertically) is formed has higher rigidity. You can do it.

Moreover, in each said example, although the case where a stopper is provided by bending the sub-plate 3 is illustrated, it is not limited to this. For example, as shown in FIG. 11, a plate 12 may be joined to the sub-plate 3 to serve as a stopper. In short, it is only necessary that a stopper portion having rigidity sufficient to regulate the amount of compressive deformation of the bead 8 protrudes into the concave portion of the bead 8.
Further, the stopper may be formed as shown in FIG. That is, a hole 17 is formed by burring in a portion of the sub-plate 3 facing the bead 8 so as to fit in the concave portion of the bead 8, and the light rising from the burring is curled and turned back to flat to set the height. A plurality of protrusions 14 that are forged and compressed to serve as stoppers are formed along the seal line SL1. The plurality of protrusions 14 regulates the amount of compressive deformation of the bead 8 so as to make the surface pressure of the bead 8 along the seal line SL1 uniform by providing an inflection to the set height.

  Alternatively, it is formed as shown in FIGS. That is, the stopper main body 15 that extends continuously along the seal line SL1 and protrudes toward the bead 8 and has a flat top is provided. Further, a rigidity improving portion 16 that protrudes or is recessed in a direction opposite to the protruding direction of the stopper body is formed continuously or intermittently along the extending direction of the stopper body with respect to the flat top portion of the stopper body 15. By doing so, the rigidity is increased and used as a stopper. FIG. 13 shows an example in which the rigidity improving portion is formed by the protrusion 16. FIG. 14 shows an example in which the rigidity improving portion is formed by the groove 16 extending along the seal line. FIG. 15 shows an example in which a burring hole 17 is opened downward, the beam 16 is curled, and forged and compressed to a set height by turning back and flat to obtain a rigidity improving portion. The stopper body 15 may be formed intermittently so as to extend along the seal line.

Moreover, although the said embodiment demonstrated in the example which made the dimension of the board | substrate 2 small with respect to the subplate 3, it is not limited to this. For example, as shown in FIG. 16, the sub-plate 3 and the substrate 2 may be designed to have substantially the same size.
Moreover, although the case where the bead of the inner peripheral side seal line SL1 surrounding the combustion chamber hole 5 is the full bead 8 is illustrated in the above embodiment, the half bead 13 may be used as shown in FIGS. . In the case of the half bead 13, it is preferable that the stoppers 9 and 10 are positioned below the top portion 13a of the bead 13 (the surface in contact with the joint surface, that is, the seal portion where the surface pressure is desired to be increased).

Moreover, in the said embodiment, although the case where the board | substrate 2 is one is illustrated, when an inner cylinder pressure is high like a diesel engine, it is good to arrange | position two board | substrates 2 on both sides of the subplate 3. FIG. . In this case, as shown in FIG. 19, the stopper 2 is arranged so that the sub-plate 3 side of the substrate 2 becomes the concave side of the bead 8 and the stopper 9 protrudes alternately on the front and back sides, so that the seal width can be reduced. It becomes possible.
Further, a plurality of sets of the substrate 2 and the sub-plate 3 as described above may be stacked to cope with high pressure.
Moreover, although the said embodiment demonstrated the seal line around a combustion chamber hole as an example, it is not limited to this. The present invention is applicable to any portion where the seal width is narrow and a stopper is required. Further, the present invention may not be applied to all the seal lines, and the present invention may be applied only to a portion where the seal width is narrow and the vicinity thereof.

It is a partial top view which concerns on embodiment based on this invention. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a top view which shows the example of a stopper. It is sectional drawing which shows another example of a stopper. . It is a top view which shows another example of a stopper. It is a top view which shows another example of a stopper. It is a top view which shows another example of a stopper. It is a top view which shows another example of a stopper. It is sectional drawing which shows another example of a stopper. It is sectional drawing which shows another example of a stopper. It is a top view which shows another example of a stopper, (a) is sectional drawing, (b) is a top view. It is a top view which shows another example of a stopper, (a) is sectional drawing, (b) is a top view. It is a top view which shows another example of a stopper, (a) is sectional drawing, (b) is a top view. It is a top view which shows another example of a stopper, (a) is sectional drawing, (b) is a top view. It is a partial top view concerning another embodiment based on the present invention. It is sectional drawing which shows the example whose bead is a half bead. It is sectional drawing which shows the example whose bead is a half bead. It is sectional drawing which shows the case where a subplate is arranged between two board | substrates.

Explanation of symbols

1 Metal gasket 2 Substrate 3 Sub-plate 5 Combustion chamber hole 6 Water hole 7 Bolt hole 8 Bead 9, 10, 11, 12
Stopper
13 Half bead 15 Stopper body 17 Burring hole 16 Stiffness improvement part

Claims (8)

A thin metal plate is used as a substrate, and a convex bead is formed on the substrate by bending the substrate in the plate thickness direction along with a preset seal line and exerting a spring in the plate thickness direction. A metal gasket,
Provided with a sub-plate laminated on the substrate from the concave side of the bead, and provided with a highly rigid stopper that protrudes into the concave portion of the bead with respect to the sub-plate and restricts the amount of compressive deformation in the plate thickness direction of the bead. Metal gasket characterized by that.   The metal gasket according to claim 1, wherein the stopper is formed continuously along the seal line.   2. The metal gasket according to claim 1, wherein the stopper includes a plurality of protrusions arranged along the seal line and projecting into the bead recess.   The metal gasket according to any one of claims 1 to 3, wherein a top portion of the stopper is flat.   The stopper is formed by bending a portion of the sub-plate facing the bead so as to protrude into the bead recess, and the stopper has a height that makes no contact with the concave surface of the bead in an unloaded state. The rigidity in the plate thickness direction is increased by changing the meandering or width along the extending direction. Metal gasket.   The stopper is formed by opening a hole in a portion of the sub-plate facing the bead with a burring, forging and compressing the flash rising from the burring and forging to a set height by flat pressing. The metal gasket according to any one of claims 1 to 4.   As the stopper, a stopper main body that extends continuously or intermittently along the seal line and protrudes toward the bead and has a flat top is provided, and the protrusion direction of the stopper main body with respect to the flat top of the stopper main body 2. The metal gasket according to claim 1, wherein the rigidity improving portion protruding or recessed in the opposite direction is formed continuously or intermittently along the extending direction of the stopper main body.   At least a combustion chamber hole is opened in the substrate, and the seal line is a seal line that surrounds the combustion chamber hole and seals the combustion chamber hole, and at least the seal line is provided on one of the substrate and the auxiliary plate. The water hole is opened to the outer peripheral side, and the other outer peripheral edge position of the substrate and the sub-plate is the position of the water hole or the combustion chamber hole side from it. Item 8. The metal gasket according to any one of items 7 to 9.

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