JPH0791548A - Metal plate gasket and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the fitting property of a thick part and peripheral parts thereof to irregularity and distortion of a sealed surface in a gasket, in which a peripheral edge of a hole of a metal plate is folded to form a projecting edge and this projecting edge is crushed to form a thick thickness part at the peripheral edge of a fluid passing hole. CONSTITUTION:A hole, of which diameter is smaller than that of a fluid passing hole 3, is provided in a metal plate 2, and an outside of the peripheral edge of the hole is bent to the direction at a right angle against the plate surface of the metal plate 2, and the peripheral edge of the hole is folded to the direction opposite to the bending direction to form a projecting peripheral edge, Next, the projecting peripheral edge is pressed for crush to form a thick thickness part 5, which is swelled on both the upper and the lower surfaces of the metal plate gasket, and a recessed part 6 extended along the periphery of the thick thickness part 5 is formed in both the upper and the lower surfaces of the gasket, and furthermore, a fluid passing hole 3 is formed inside of the thick thickness part 5.

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 For example, in a metal plate gasket for sealing a fluid flow hole such as a combustion chamber or an exhaust hole of an engine, it is known to form a thick wall portion around the fluid flow hole to improve the sealing performance. . In addition, JP-A-54-1332
As a method of manufacturing a metal plate gasket having such a thick wall portion, Japanese Patent Laid-Open No. 13-31200 discloses that a hole having a diameter slightly smaller than a diameter of a fluid circulation hole is provided in a metal plate, and the periphery of the hole is formed on the plate surface of the metal plate. Bending in a substantially perpendicular direction to form a protruding peripheral edge, and then crushing the protruding peripheral edge with a press to form a thick portion that bulges substantially evenly from both surfaces of the metal plate and the inside of the thick portion. Describes a method of forming a fluid communication hole.

The above-described manufacturing method for manufacturing a metal plate gasket having a thick portion on the periphery of the fluid passage hole by crushing the protruding peripheral edge is, for example, a method of forming the thick portion by thermal spraying or etching other than the thick portion. Unlike a method that requires a special processing means such as a method for forming a thick wall portion, the metal plate gasket can be manufactured relatively easily by a processing means that is usually used for manufacturing a metal plate gasket. Unlike the method in which the thickness is formed by folding the metal plate itself or the grommet plate that forms the gasket and the thickness of the thick part is determined by the thickness of the metal plate itself or the thickness of the grommet plate, the thick part It has the advantage that it is relatively easy to properly adjust the thickness of the to the desired thickness.

However, in the metal plate gasket manufactured by the above-mentioned manufacturing method, since the thick portion is formed by crushing the projecting peripheral edge, work hardening occurs by crushing in the thick portion and its periphery, and the metal plate gasket The hardness is higher than that of the other portions, and the hardened portion loses the conformability to the unevenness and distortion of the joint surface to be sealed. Since the portion in which the conformability is impaired forms the seal portion for the fluid passage hole, the metal plate gasket obtained by the above-mentioned manufacturing method is still unsatisfactory in sealing performance.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and the protruding peripheral edge formed by bending the peripheral edge of the hole portion of the metal plate is crushed and bulged on both sides of the metal plate surface. It is an object of the present invention to improve the conformability of the metal plate gasket having the thick portion and the fluid passage hole inside the thick portion to the irregularities and distortion of the joint surface of the thick portion and its periphery.

[0006]

According to the present invention to achieve the above object, a thick wall portion bulged on both upper and lower surfaces of a metal plate by crushing a protruding peripheral edge formed by bending a peripheral edge of a hole portion of a metal plate, and A metal plate gasket having a fluid passage hole inside thereof is characterized in that recesses extending along the outer periphery of the thick portion are provided on both upper and lower surfaces of the metal plate gasket.

In the method for manufacturing a metal plate gasket according to the present invention, the metal plate is provided with a hole portion having a diameter smaller than that of the fluid passage hole.
A little outside of the periphery of the hole is bent in a direction substantially perpendicular to the plate surface of the metal plate, and the periphery of the hole is bent in a direction opposite to the direction of bending to form a protruding periphery, and ,
The projecting peripheral edge is crushed by a press to form a bulged thick portion on both upper and lower surfaces of the metal plate gasket, and a recessed portion that extends along the outer periphery of the thick portion is formed on the upper and lower surfaces of the metal plate gasket, Further, the invention is characterized in that a fluid communication hole is formed inside the thick portion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a metal plate gasket and a method for manufacturing the same according to the present invention will be described below with reference to the drawings of the embodiments. 1 is a plan view of an embodiment of a metal plate gasket 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 (A),
5B and FIGS. 5A and 5B are explanatory views (cross-sectional views) illustrating an embodiment of the method for manufacturing a metal plate gasket according to the present invention. In each figure, the same reference numerals indicate the same parts.

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 3 such as a combustion chamber hole or an exhaust hole of an engine. And a bolt insertion hole 4 through which a bolt for fastening is inserted. Metal plate gasket 1
A thick portion 5 is provided on the periphery of the fluid circulation hole 3 so as to surround the fluid circulation hole 3. As will be described later in detail, the thick-walled portion 5 is formed by crushing the protruding peripheral edge formed by bending the peripheral edge of the hole of a metal plate such as an iron plate or a stainless steel plate forming the gasket 1. The metal plate 2 is formed so as to bulge at a height of H ₁ from the upper surface and bulge at a height of H ₂ from the lower surface.

Outside the thick-walled portion 5, recesses 6 extending along the outer periphery of the thick-walled portion 5 are provided on the upper and lower surfaces of the metal plate gasket, respectively. An outer bulge portion 7 is formed which extends along the outer periphery of the portion 6 and bulges out at the same height as the bulge height H ₁ of the thick portion 5. However, the outer bulging portion 7 is not essential to the present invention, and the metal plate gasket of the present invention can be formed without the outer bulging portion 7.

The sum of the heights H ₁ and H ₂ of the bulges, that is, the difference T ₂ between the thickness T _{2 of the} thick portion and the thickness T ₁ of the metal plate ₂ −
The size of T ₁ needs to be 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 and the width of the thick portion. This step T ₂
If the magnitude of −T ₁ is too small, the required surface pressure cannot be obtained and fluid leakage occurs. On the contrary, if the size of the step is excessively large, the tightening force is excessively consumed, and the surface pressure distribution of the entire gasket is impaired. In the metal plate gasket according to the present invention, by appropriately selecting the bulging heights H ₁ and H ₂ of the thick portion 5, the size of the step T ₂ −T ₁ is appropriately adjusted, and the metal plate gasket 1 is sealed. Performance can be improved.

Further, since the metal plate gasket 1 of the present invention is provided with the recessed portions 6 extending along the outer periphery of the thick portion 5 on the upper and lower surfaces thereof, the thick portion 5 is centered on the recessed portion 6. It becomes easy to bend, and as a result, flexibility is imparted to the thick-walled portion and its periphery that have been work-hardened by bending and crushing. Therefore, according to the present invention, the conformability of the joint surface to be sealed, for example, the concavity and convexity of the joint surface of the engine cylinder head or block to the thick portion and its periphery is improved, and the sealing performance of the metal plate gasket 1 is improved. To do.

The metal plate gasket 1 having the structure described above can be manufactured by the following method. Figure 4 (A)
As shown in FIG. 5, the lower die 9 is provided with a groove portion 11 having a depth h _4, a vertical surface 12 in contact with the inner peripheral side of the groove portion 11, and a step portion 13 provided above the vertical surface, and the groove portion 11 described above. The metal plate 2 provided with the hole 8 having a diameter smaller than that of the fluid circulation hole 3 is mounted between the metal plate 2 and the upper die 10 having the protrusion 14 having a height h ₃ facing the
As shown in (B), the metal plate 2 is pressed and formed by the upper mold 10 and the lower mold 9.

By this press forming, the groove portion 1 is formed in the metal plate 2 around the hole portion 8 and slightly outside the hole portion 8.
1. A bent portion bent in the depth direction of 1, that is, a bent portion 15 bent in a direction substantially perpendicular to the plate surface of the metal plate 2 is formed, and the periphery of the hole 8 is bent along the vertical surface 12 to project. A protruding peripheral edge 16 is formed by bending the peripheral edge, that is, the peripheral edge of the hole portion 8 in a direction opposite to the bending direction of the bending portion 15.

Next, as shown in FIG. 5 (A), the groove portion 1
The metal plate 2 formed as described above is mounted between the lower die 17 of the crushing die having 9 and the upper die 18 having the groove portion 21. At this time, the left side surface 20 of the lower die 17 and the vertical surface 2 of the upper die
It is arranged so that 2 and 2 are in contact with each other. Then, as shown in FIG. 5B, by pressing the metal plate 2 with the lower mold 17 and the upper mold 18, the protruding peripheral edge 16 is crushed to form the thick portion 5, and the inside of the thick portion 5 is formed. The fluid passage hole 3 is formed in the metal plate gasket 1, and the metal plate gasket 1 having the thick portion 5 is formed on the periphery of the fluid passage hole 3. Since the bent portion 15 described above is provided on the metal plate 2, during the above press molding,
The upper surface side of the metal plate gasket 1 is inside the bent portion 15, and the lower surface side of the metal plate gasket is outside the bent portion 15, both of which are recessed portions 6 and 6 extending along the outer periphery of the thick portion.
Is formed. An outer bulge 7 is formed outside the recess 6 on the upper surface side of the metal plate gasket.

The thick portion 5 has a depth h of the groove portion 21 of the upper mold 18.
₁ and than by the thickness the top surface of the metal plate 2 of an H ₁ of the same dimensions bulges upward, and the thickness only the lower surface of the metal plate 2 of H ₂ depth h ₂ of the same dimension of the groove 19 of the lower die 17 Swells further downward than the thickness of the thick portion 5 and the thickness of the metal plate 2 by H ₁ +
A step of H ₂ is formed. Therefore, the upper mold 18 and the lower mold 1
By appropriately selecting the depths h ₁ and h ₂ of the groove portions 21 and 19 of _{No. 7} , the difference between the thickness T ₂ of the thick portion 5 and the thickness T ₁ of the metal plate 2, that is, the step H ₁ + H ₂ is appropriately adjusted. Can be adjusted. The size of the step H ₁ + H ₂ is usually 0.05 to
It is selected in the range of 0.15 mm. The depths h ₁ and h ₂ of the groove portions 21 and 19 may be equalized so that the bulging thicknesses H ₁ and H ₂ are equalized.
When there is a difference in surface roughness or distortion between the two joint surfaces to be mounted with, the thick part should be thickened so that the bulge height on the surface side in contact with the joint surface with a large surface roughness, distortion, etc. Is preferably molded.

The width W of the thick wall portion 5 (see FIG. 1) can be adjusted as appropriate by selecting the height E of the protruding peripheral edge 16. The height of the protruding peripheral edge 16 can be adjusted by adjusting the height of the hole of the metal plate 2. This can be done by appropriately selecting the inner diameter of the portion 8. The size of the recessed portion 6 on the lower surface side of the metal plate gasket 1 is the bent portion 1
It can be adjusted by adjusting the bending length of No. 5, specifically by selecting the depth h ₄ of the groove portion 11 of the lower mold 9. The size of the recess 6 on the upper surface side of the metal gasket 1 changes depending on the height h ₃ of the protrusion of the upper die 10 and the height E of the protruding peripheral edge 16.

Similarly to the thick-walled portion 5, the outer bulging portion 7 has a thickness of H _{1 which} is the same as the depth h ₁ of the groove portion 21 and is equal to the thickness of the metal plate 2.
Bulges above the upper surface of the. Groove portion 21 of upper mold 18
If the pressing is performed by reducing the width of the groove 21 so that the outer edge of the groove portion 21 is located inside the bent portion 15, the outer bulging portion is not formed, and the outer side of the recessed portion 6 does not have the metal plate 2 of the metal plate 2. Aligned flush with the top surface. Instead of bending the bent portion 15 and forming the protruding peripheral edge by bending at the same time as in the above embodiment, the bent portion 15 is bent first, and then the peripheral edge of the hole 8 is bent to project. Of course, it does not matter if the peripheral edge is formed.

Now, the above-mentioned prior art JP-A-54-1
Although not described or suggested in the invention described in Japanese Patent No. 33213, the thick wall portion 5 formed by crushing the projecting peripheral edge.
It may be beneficial to improve the sealing performance of the metal plate gasket by varying the thickness of the metal plate around the fluid passage hole. For example, the thick portion 5 is made thicker at a position separated from the bolt fastening portion in the vicinity of the fluid circulation hole 3 to increase the step T ₂ -T ₁ , and at the position close to the bolt fastening portion. the thickness of the wall portion thin to step T ₂ -T ₁
By reducing, the thickness of the thick portion can be changed according to the tightening force acting on each portion, and the surface pressure of each portion can be adjusted.

FIG. 3 shows the change in the thickness of the thick wall portion 5 along the circumference of the fluid flow hole. From the B position, that is, the bolt fastening position, in the thick wall portion at the periphery of the fluid flow hole. In the vicinity of the separated position (see FIG. 1), the thickness T ₂ of the thick portion is increased to increase the step T ₂ −T ₁ , and the B ′ position, that is, the position close to the bolt fastening position (see FIG. 1). In the vicinity, the thickness T ₂ of the thick portion is thinned to reduce the step T ₂ −T ₁ . And in the middle of these, the thickness T of the thick portion
₂ is gradually changed.

When the metal plate gasket according to the present invention is formed as a cylinder head gasket having a plurality of combustion chamber holes, thermal effects such as a portion around the combustion chamber holes and adjacent combustion chamber holes are provided. The thickness of the thick portion of the portion that receives a large amount may be thicker than the thickness of other portions of the thick portion.

As described above, in order to change the thickness of the thick portion 5 along the peripheral edge of the fluid circulation hole 3, the groove portion of the upper die 18 of the crushing die in the above-described metal plate gasket manufacturing method of the present invention. The depth h ₁ of the groove 21 and the depth h ₂ of the groove portion 19 of the lower mold 17 may be partially changed along the circumferential direction of the groove portions 21 and 19. In addition to this, if necessary, the height I of the protruding peripheral edge 16 may be preliminarily molded so as to partially change along the circumferential direction of the protruding peripheral edge. Since the height of the protruding peripheral edge 16 can be adjusted by the diameter of the hole portion 8 of the metal plate 2 as described above, in this case, the inner periphery of the hole portion 8 has a concave convex portion corresponding to the height of each portion of the protruding peripheral edge 16. It is necessary to adjust it to the shape it has.

The metal plate gasket 1 according to the present invention described in detail above is a single plate and can be used as a gasket for various purposes. In that case, as shown in the cross-sectional view of FIG. 6, a bead 23 may be provided outside the thick wall portion 5 and the recess portion 6. Further, the metal plate gasket of the present invention can be laminated to form a laminated metal plate gasket. In FIG. 7, the metal plate gasket 1 above and below the metal plate gasket 1 according to the present invention is outside the thick portion 5 and the recessed portion 6. Metal plates 24, 24 each having a bead 25 formed so as to surround the fluid circulation hole 3 at the position
5 is a cross-sectional view of a laminated metal plate gasket in which the beads 25 are laminated so that the tops of the beads 25 face each other.

[0024]

As described above, in the metal plate gasket and the method for manufacturing the same according to the present invention, the protruding peripheral edge formed by bending the peripheral edge of the hole portion having a diameter smaller than that of the fluid passage hole provided in the metal plate is crushed. Since the thick-walled portion is formed around the fluid passage hole, the thick-walled portion can be easily formed by the usual processing means in the metal plate gasket, and the thickness of the thick-walled portion can be reduced along the periphery of the fluid passage hole. It can be changed partially, and the surface pressure in each part can be adjusted. Moreover, according to the present invention, since the recesses extending along the outer periphery of the thick portion are formed on the upper and lower surfaces of the metal plate gasket, the conformability to the thick portion and the bonding surface around the thick portion is improved. Therefore, according to the present invention, the sealing performance of the metal plate gasket can be significantly improved.

[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 an enlarged cross-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 (A) is an explanatory view for explaining the method for manufacturing a metal plate gasket according to the present invention, and shows a front stage of the bending and bending steps of the metal plate. (B) is an explanatory view showing the latter stage of the same step as (A).

FIG. 5A is an explanatory view for explaining the method for manufacturing the metal plate gasket according to the present invention, showing a front stage of the step of crushing the protruding peripheral edge. (B) is an explanatory view showing the latter stage of the same step as (A).

FIG. 6 is a view of another embodiment of the metal plate gasket of the present invention.
It is a sectional view corresponding to.

FIG. 7 is a cross-sectional view of still another embodiment of the metal plate gasket of the present invention, which corresponds to FIG.

[Explanation of symbols]

 3 Fluid Circulation Holes 5 Thick Walls 6 Recesses 8 Holes 9 Lower Molds 10 Upper Molds 15 Bent Parts 16 Bending Edges 17 Lower Molds 18 Upper Molds

Claims (3)

[Claims] 1. A metal plate gasket in which a protruding peripheral edge formed by bending a peripheral edge of a hole portion of a metal plate is crushed to bulge on both upper and lower surfaces of the metal plate and a fluid passage hole inside thereof is formed. A metal plate gasket, characterized in that recesses extending along the outer periphery of the thick portion are provided on the upper and lower surfaces of the metal plate gasket. 2. The metal plate gasket according to claim 1, wherein the thickness of the thick portion is changed along the periphery of the fluid passage hole. 3. A metal plate is provided with a hole having a diameter smaller than that of the fluid passage hole, and a portion of the periphery of the hole is bent in a direction substantially perpendicular to the plate surface of the metal plate, and the periphery of the hole is formed. Bending in a direction opposite to the direction of the above bending to form a protruding peripheral edge, then crushing the protruding peripheral edge by a press to form bulged thick portions on the upper and lower surfaces of the metal plate gasket,
A method for manufacturing a metal plate gasket, characterized in that recesses extending along the outer periphery of the thick portion are formed on both upper and lower surfaces of the metal plate gasket, and further fluid passage holes are formed inside the thick portion.