JPH0771603A - Metal plate gasket and manufacture thereof - Google Patents

Abstract

PURPOSE:To change the thickness of a thick-wall portion provided at the inner periphery of a fluid passage hole of a gasket along the periphery of the fluid passage hole, as well as to easily adjust the thickness of the thick-wall portion. CONSTITUTION:A hole portion 8 having a diameter greater than that of a fluid passage hole 2 is provided in a main body 4 of a metal plate. A metal-wire ring having a thickness sufficiently greater than the thickness of the metal plate main body 4 is fitted in the inner periphery of the hole portion 8. The metal wire is crushed to a thickness t2 which is a desired level difference t3 thicker than the thickness t1 of the metal plate main body t1. The metal wire is thereby pressed against the inner periphery of the hole portion 8 to form a thick-wall portion 6. By partially changing the amount of crush of the metal wire in the circumferential direction of the ring, the thickness of the thick-wall portion 6 is circumferentially changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal plate gasket for sealing a fluid flow hole such as a combustion chamber or an exhaust hole of an engine.

[0002]

2. Description of the Related Art In a metal plate gasket for sealing a fluid flow hole such as a combustion chamber or an exhaust hole of an engine, a thick wall portion is formed at the periphery of the fluid flow hole, and the thick wall portion is used for fluid flow. It is publicly known that the metal plate gasket plate is formed by folding back the metal plate gasket plate at the periphery of the hole or the grommet plate is formed by folding back.

It is also known to form a thick portion on the periphery of the fluid passage hole by welding a shim plate around the fluid passage hole of the metal plate gasket to be sealed or by overlaying it by thermal spraying. is there. Further, in order to form a thick portion around the fluid passage hole, it has been proposed to thin a portion other than the peripheral edge portion of the fluid passage hole by etching or coining.

However, when the thick portion is formed by folding the metal gasket plate itself or by folding the grommet plate, the thickness of the thick portion is the thickness of the metal gasket plate itself or the grommet plate. It is difficult to adjust the thickness of the thick portion appropriately so that an appropriate surface pressure is given to the thick portion, especially when the thickness of the thick portion is changed from the bolt fastening portion, for example. It cannot be locally changed along the periphery of the fluid flow hole to be sealed, for example, thickening at a distance and thinning at a position near the bolt fastening portion.

In the case of shim plate welding, there are basically similar problems. Both thermal spraying and etching have the disadvantage that special equipment is required, and when coining, a large capacity press is required when the area of the thinned part is large. The variation is also large. Moreover, it is difficult to locally change the thickness of the thick portion along the circumference of the fluid passage hole by etching or coining.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to appropriately and easily adjust the thickness at the peripheral edge of a fluid passage hole to be sealed. Another object of the present invention is to provide a metal plate gasket having a thick portion that can be formed by using a usual processing means for processing a metal gasket, and a method for manufacturing the same. It is an object of the present invention to provide a metal plate gasket in which the thickness of the thick portion can be appropriately changed partially along the periphery of the metal plate gasket and a method for manufacturing the same.

[0007]

MEANS FOR SOLVING THE PROBLEMS A metal plate gasket of the present invention which achieves the above object is a metal plate main body having a hole portion having a diameter larger than the diameter of a fluid flow hole to be sealed, and a thickness of the metal plate main body. And a thick wall portion formed of a metal wire ring crushed to a thickness thicker by a desired step amount and pressed against the inner circumference of the hole portion, and a fluid passage hole is formed inside the thick wall portion. It is characterized by that.

Further, in the method for manufacturing a metal plate gasket according to the present invention, a hole portion having a diameter larger than that of the fluid passage hole to be sealed is provided in the metal plate body, and the inner circumference of the hole portion is thinner than the thickness of the metal plate body. By fitting a metal wire ring having a sufficiently large thickness, and then crushing the metal wire ring into a thickness thicker by a desired step amount than the thickness of the metal plate body, the metal wire ring is formed. A thick wall portion thicker by a desired step amount than the thickness of the metal plate main body is formed on the periphery of the fluid flow hole while forming a fluid flow hole inside the pressed metal wire ring. It is characterized by forming.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings of the embodiments. 1 is a plan view of a metal plate gasket of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. FIG. 3 is an enlarged cross-sectional view showing a cross-sectional profile taken along the line BB ′ in FIG. 1 and exaggerating the change in thickness. FIG. 4 is an explanatory view (cross-sectional view) for explaining an embodiment of the method for manufacturing a metal plate gasket according to the present invention.

In the drawings, reference numeral 1 denotes a metal plate gasket of an embodiment of the present invention, which seals a metal plate gasket with a fluid flow hole 2 such as a combustion chamber hole or an exhaust hole of an engine. And a bolt insertion hole 3 through which a bolt to be fastened is inserted. The metal plate gasket 1 is made of, for example, an iron plate, a stainless steel plate, or the like,
A metal plate body 4 provided with a hole 8 having a diameter larger than the diameter of the fluid flow hole to be sealed, and a thickness t _{1 of the} metal plate body 4.
And a thick portion 6 made of a metal wire ring crushed to a thickness t ₂ thicker by a desired step amount t ₃ and pressed against the inner circumference of the hole portion 8. The fluid circulation hole 2 is formed inside the inner wall 6. In other words, the thick portion 6 is formed on the peripheral edge of the fluid circulation hole 2.

The crushed and crimped metal wire ring forming the thick portion 6 has a thickness (outer diameter) sufficiently larger than the thickness of the metal plate body 4, that is, a soft iron wire or a squeezing margin. Is a ring 5 (see FIG. 4) of a metal wire such as a stainless steel wire crushed to the above-mentioned thickness t ₂ , and a flat portion 7 abutting on the joint surface to be sealed is formed on the lower surface thereof.
Are formed. Further, in the embodiment shown in FIG. 2, the thick wall portion 6 is evenly projected vertically from the metal plate body 4. The sectional shape of the metal wire ring 5 before being crushed is not limited to the circular shape as shown in FIG. 4, and may be an elliptic rectangular sectional shape or the like, or a circular sectional shape or the like may be pre-compressed.

The thickness of the thick portion 6 is appropriately adjusted in consideration of the pressure of the fluid to be sealed, the rigidity of the joint surface, the distortion and surface roughness of the joint surface, the tightening force, the width of the thick portion, and the like. Must be,
If the thickness of the thick portion is too small, the required surface pressure cannot be obtained and fluid leakage occurs. If the thickness of the thick portion is excessively large, the tightening force is excessively consumed, and an obstacle such as damage to the surface pressure distribution of the entire gasket is likely to occur. In the metal plate gasket according to the present invention, the thickness t ₂ of the thick portion 6 and the width of the flat portion 7 are set by appropriately selecting the thickness (outer diameter) of the ring 5 of the metal wire before being crushed and the crush amount. W can be adjusted appropriately.

The metal plate gasket 1 having the above-described structure can be manufactured by the following method. First, the metal plate body 4 is provided with a hole portion 8 having a diameter larger than the diameter of the fluid passage hole to be sealed, and then, as shown in FIG. 4, the inner circumference of the hole portion 8 is sufficiently larger than the thickness of the metal plate body 4. Then, the metal wire ring 5 having a large thickness (outer diameter) is fitted. After that, the ring 5 of the metal wire is preferably subjected to coining to obtain a desired step difference t from the thickness t ₁ of the metal plate body 4.
_The metal wire ring having the flat portion 7, that is, the thick portion 6 is formed by pressing the inner periphery of the hole portion 8 of the metal plate body 4 by crushing it to a thickness t ₂ thicker by ₃ . At this time, as shown in FIG. 2, a part of the metal ring may be caulked so as to cover the end of the metal plate body 4.

FIG. 4 also shows a cross section of a die T for coining for crushing the metal wire ring 5. The mold T is provided with a general wall thickness portion A, a step setting groove portion B, and a hole inner peripheral side convex portion C, and the crushing amount is appropriately adjusted by appropriately selecting the depth of the step setting groove portion B. As a result, the thickness of the thick portion 6 can be adjusted appropriately.

In the present invention described above, the thickness t ₁ of the metal plate body 4 and the preferable range of the wire diameter φ of the ring 5 of the metal wire to be combined therewith and the thick portion obtained by crushing the metal wire ring 5 are obtained. 6 has a thickness t ₂ and the metal plate body 4 has a thickness t 2.
Table 1 shows an example of the difference from ₁ , that is, the step amount t ₃ and the range of the value of the width W of the flat portion.

[0016]

[Table 1]

In the metal plate gasket and the method for manufacturing the same according to the present invention, the crushing amount of the ring 5 of the metal wire is changed along the circumferential direction of the ring to thicken the peripheral wall of the fluid passage hole 2 to be sealed. The thickness of the portion 6 is set to the fluid circulation hole 2
Along the circumference of the fluid flow hole, for example, increase the thickness of the thick-walled part in the part that is separated from the bolt fastening part in the periphery of the fluid circulation hole and increase the thickness in the part that is close to the bolt fastening part. It is also easy to reduce the thickness of the thick portion and change the thickness of the thick portion according to the tightening force, thereby adjusting the surface pressure of each portion.

FIG. 3 shows the change in the thickness of the thick portion 6 along the circumference of the fluid passage hole, and in the thick portion at the periphery of the fluid passage hole, the B'position, that is, the bolt fastening position. In the vicinity of the position separated from (see FIG. 1), the thickness t _{2 of the} thick portion is
The thickness of the thick to thick portion thickness t ₂ and the metal plate body 4 t ₁
Position thickness t ₂ and the metal plate body of the thick portion by reducing the thickness t ₂ of the thick portion 6 in the vicinity (see FIG. 1) the difference in proximity to a large city, B position or bolt fastening portions of the The difference from the thickness t _{1 of No.} 4 is made small, and the thickness t ₂ of the thick portion is gradually changed between them.

In the coining process using the above-mentioned mold T, the crushing amount of the metal wire ring 5 is changed along the circumferential direction of the ring as described above, and the thickness of the thick portion 6 is changed along the circumferential direction. For this purpose, the depth of the step setting groove B of the mold T may be changed along the circumferential direction.

FIG. 5 is a sectional view corresponding to FIG. 2 showing another embodiment of the metal plate gasket according to the present invention. In this embodiment, the thick portion 6 is formed such that its lower surface is flush with the lower surface of the metal plate body 4, and only the upper surface side projects from the upper surface of the metal plate body 4 to form a step. In order to form such a metal plate gasket by coining using the above-described mold T, a mold having no step setting groove B in the lower mold T in FIG. 4 may be used. In the drawing, the end portion on the upper surface side of the thick portion is not crimped so as to cover the end portion of the upper surface of the metal plate body 4, but of course, it may be crimped as shown in FIG.

FIG. 6 is a cross-sectional view corresponding to FIG. 2, showing an example of a laminated metal plate gasket in which a metal plate gasket according to the present invention and a metal plate gasket having beads around fluid passage holes are laminated. In this embodiment, a metal plate gasket 1 provided with beads 10 on the upper and lower sides of the metal plate gasket 1 according to the present invention so as to surround the fluid flow holes 2 and to be located outside the thick portion 6 of the metal plate gasket 1. 9
Are laminated so that the convex portions of the beads 10 and 10 face each other. In such a laminated gasket, the fluid passage hole 2 is doubly sealed by the thick portion 6 and the bead 10, and the sealing performance and its reliability are improved.

When the above-mentioned laminated metal plate gasket is used as a cylinder head gasket of an engine and the fluid passage hole to be sealed is a combustion chamber hole, the thick portion 6 is a cylinder formed by a bolt fastening force. It functions as a compensator that compensates for the gap around the combustion chamber caused by the bending of the head, prevents the leakage of combustion gas, and expands or contracts the gap between the joint surface between the cylinder head and cylinder block due to the gas pressure in the combustion chamber. Based on the above, the alternating load applied to the bead is reduced to prevent the bead from sagging or being damaged.

Further, when the cylinder head gasket made of the above-mentioned laminated metal plate gasket has a plurality of combustion chamber holes, the combustion chamber holes which are doubly affected by thermal effects around the combustion chamber holes. Make the thick part thicker than the thick part in other parts in the part between and in the vicinity of the exhaust port to prevent the bead of the part that is strongly affected by heat from being damaged or damaged. You may do it.

[0024]

As described above, in the metal plate gasket and the method of manufacturing the same according to the present invention, the ring of the metal wire having a thickness (outer diameter) sufficiently larger than the thickness of the metal plate body is used. By crushing into a thickness thicker by a desired step amount than the above and press-contacting with the inner circumference of the hole provided in the metal plate body, the thick part at the periphery of the fluid circulation hole to be sealed can be easily formed, and By appropriately selecting the thickness (outer diameter) of the metal wire before crushing and the amount of crushing, the thickness of the thick portion and the sealing width (width of the flat portion 7) by the thick portion can be adjusted appropriately. You can easily.

Further, according to the present invention, the crushing amount of the metal wire is partially changed along the circumferential direction of the ring of the metal wire, so that the thickness of the thick portion is partially changed along the circumferential direction. Can be changed to. Therefore, for example, it is possible to easily change the thickness of the thick portion according to the bolt tightening force in each portion and adjust the surface pressure of each portion.

[Brief description of drawings]

FIG. 1 is a plan view of a metal plate gasket according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged cross-sectional view taken along the line BB ′ of FIG.

FIG. 4 is an explanatory diagram for explaining an example of a method for manufacturing a metal plate gasket according to the present invention.

5 is a cross-sectional view corresponding to FIG. 2 of another embodiment of the metal plate gasket of the present invention.

FIG. 6 is a cross-sectional view corresponding to FIG. 2 of a laminated metal plate gasket in which a metal plate gasket according to the present invention and a metal plate gasket including beads are laminated.

[Explanation of symbols]

 2 Fluid circulation hole 4 Metal plate body 5 Metal wire ring (before crushing) 6 Thick part 7 Flat part

Claims (2)

[Claims] 1. A metal plate body provided with a hole having a diameter larger than the diameter of a fluid flow hole to be sealed, and a metal plate body crushed to a thickness which is larger than a thickness of the metal plate body by a desired step amount and the hole portion. And a thick portion formed of a metal wire ring that is pressed against the inner periphery of the metal plate gasket, and a fluid passage hole is formed inside the thick portion. 2. A metal wire ring having a hole having a diameter larger than that of a fluid passage hole to be sealed in the metal plate body, and having a thickness sufficiently larger than the thickness of the metal plate body on the inner circumference of the hole. , And then crushing the metal wire ring into a thickness that is thicker than the thickness of the metal plate body by a desired step amount to press the metal wire ring into the inner circumference of the hole portion of the metal plate body,
A metal plate gasket, characterized in that a fluid passage hole is formed inside the pressed metal wire ring, and a thick portion thicker by a desired step amount than the thickness of the metal plate body is formed at the periphery of the fluid passage hole. Manufacturing method.