Method for connecting laminated metal plates and press mold

In a method for connecting laminated metal plates comprising the steps of forming a plurality of cutting lines independent from each other in a laminated metal plate, and forming a projecting portion by making a metal plate between the cutting line protrude in a laminating direction by a step that is higher than the thickness of the laminated plate, the following solutions are adopted with a view to preventing securely the dislocation of the metal plates in the laminating direction and also preventing securely the deviation of the metal plate in every direction in the laminated plate surface by the two cutting lines. After forming on the laminated metal plate a projecting portion including the central portion thereof through engagement of male and female molds, the laminated metal plate is pressurized between pressing convex portion and an engagement surface so as to pressingly expand an end to be cut in a gap between the male and female molds, whereby this end to be cut is caused to overlap an end to be cut of the central portion of the projecting portion in the laminating direction. In addition, the cutting lines are formed so as to radially extend from a central point of the central portion of the projecting portion.

The present invention relates to method for connecting laminated metal 
plates such as a metal gasket or the like formed by laminating a plurality 
of metal plates including a base plate and a sub-plate, and to a press 
mold used for the same. 
BACKGROUND ART 
Conventionally, in a metal gasket formed by superposing a plurality of 
metal plates, as shown in FIG. 19, the plurality of metal plates are 
connected in a laminating direction by forming a connecting portion 41 of 
a tongue shape at an outer peripheral edge outside a joining surface 
between a cylinder block and a cylinder head, and by forming an eyelet 
hole 5 by forming a through hole in the connecting portion 41, inserting a 
metal fitting for locking through the hole, and by collapsing the metal 
fitting, and alternatively, the metal plates are welded at this connecting 
portion 41. 
However, the method by means of the eyelet hole requires labour hours for 
connecting work, and the method by the welding requires facility cost 
although the labour hours are reduced. Thus, a method for making the 
connecting work easy is required. 
In this respect, Japanese Patent Laid Open Publication Hei No. 6-281011 
discloses a method for connecting a metal gasket by a press work. In this 
method, as shown in FIGS. 20 to 22, a plurality of cutting lines 30a 
independent of one another are formed in laminated metal plates, and at 
the same time, a projecting portion 30b is formed by protruding a metal 
plate portion between the cutting lines 30a by a height larger than a 
thickness of the laminated metal plates in a laminating direction, and 
furthermore, a burr is formed at the cut end portion by making a break 
line by extending a portion 30c of the cutting line 30a. 
In this method, the displacement or slippage of the laminated metal plates 
in the plate plane in a direction intersecting an extending direction of 
the cutting line is prevented by collision, at opposite ends of the 
cutting line, between a cut end face of the laminated metal plate portion 
not protruded and an end face of the protruded portion, and the slippage 
or displacement of the laminated metal plates in the laminating direction 
is prevented by spring back of the burr. 
However, in the connecting structure described in the above-mentioned 
Japanese Patent Laid Open Publication Hei No. 6-281011 as shown in FIGS. 
20 to 22, it is described that when viewed in the laminating direction, 
the tip end portions of the burrs overlap with each other and the 
overlapped portions serve as the slippage or displacement preventing 
means, however, in practice, the slippage or displacement preventing 
effect was not sufficient. Furthermore, in order to prevent the 
displacement in every direction in the plate plane of the laminated metal 
plates, it is necessary to form three or more cutting lines as shown in 
FIG. 20 or 21, and a problem is involved in which a mold used to form such 
a connecting structure has a complicated structure, and it is easily 
broken and the cost is high. 
The present invention was made in view of the problems in the prior art as 
mentioned above, and it is a subject to provide a method which prevents 
the slippage or displacement of the metal plates in the laminating 
direction, and which prevents the displacement of the laminated metal 
plates in every direction in the plate plane without making a mold shape 
complicated, and still, can be done by press forming of one time, and to 
provide a press mold used for the method. 
DISCLOSURE OF THE INVENTION 
In order to solve the above mentioned subject, the invention provides a 
method for connecting laminated metal plates, in the method for connecting 
laminated metal plates with each other by forming two cutting lines 
mutually independent of each other in the laminated metal plates, and by 
forming a projecting portion by protruding a metal plate portion between 
the cutting lines by a step having a height larger than a laminated metal 
thickness in a laminating direction. It is characterized in that after 
forming the protecting portion, a cut end portion of the metal plates from 
which the projecting portion is cut out is pressed and expanded. 
According to this method, since the cut end portion at which the metal 
plates are expanded is made to overlap with the cut end portion of the 
projecting portion in the laminating direction, the slippage or 
displacement of the metal plates in the laminating direction is surely 
prevented. 
In the invention, it is characterized in that the projecting portion is 
constituted by a center portion protruding highest from the surface of the 
metal plates which are not protruded, and a pair of slant surface portions 
which are slanted from the center portion towards the surface of the metal 
plates, and the total of four slant surface forming portions of each 
cutting line are formed so that two slant surface forming portions which 
are adjacent to each other in a circumferential direction are directed 
respectively to two different directions in the plane of the laminated 
metal plates. 
According to this method the displacement among the metal plates in every 
direction in the plane of the laminated metal plates is prevented by the 
two cutting lines. By virtue of this, since the length of the cutting 
lines can be increased with respect to the size of the projecting portion, 
the displacement among the metal plates in the plane of the laminated 
metal plates is surely prevented. Furthermore, when the cutting lines are 
made long, since the center portion of the projecting portion can be made 
large, it is possible to increase the cut end portion of the expanded 
metal plates so as to ensure sufficient overlap with the cut end portion 
of the projecting portion. Thus, the slippage or displacement of the metal 
plates in the laminating direction can be securely prevented. 
The invention is further characterized in that the slant surface forming 
portions respectively extend along lines extending radially from the 
center portion. 
According to this method, since it is possible to widen a rising width of 
the projecting portion while increasing the length of the cutting lines, 
the displacement among the metal plates in the plane of the laminated 
metal plates can be surely prevented while maintaining the strength of the 
rising portion of the projecting portion. 
In the invention, a method for connecting laminated metal plates is 
provided, in which the method for connecting laminated metal plates with 
each other by forming two cutting lines independent of each other in the 
laminated metal plates, and at the same time, by forming a projecting 
portion by protruding a metal plate portion between the cutting lines by a 
step having a height larger than a thickness of the laminated metal plates 
in a laminating direction, is characterized in that the projecting portion 
is constituted by a center portion protruding highest from the surface of 
the metal plates from which the projecting portion is cut out, and a pair 
of slant surface portions which are slanted from the center portion 
towards the surface of the metal plates, and the total of four slant 
surface forming portions of each of the cutting lines are formed so that 
two slant surface forming portions adjacent to each other in a 
circumferential direction are directed to two different directions in the 
plane of the laminated metal plates. 
The invention is characterized in that the slant surface forming portions 
respectively extend along lines extending radially from the center 
portion. 
The invention provides a method for connecting laminated metal plates, in 
which the method for connecting laminated metal plates with each other by 
forming two cutting lines independent of each other in the laminated metal 
plates, and at the same time, by forming a projecting portion by 
protruding a metal plate portion between the cutting lines by a step 
having a height larger than a thickness of the laminated metal plates in a 
laminating direction, is characterized in that the projecting portion is 
pressed and deformed so that, in sections of the projecting portion in a 
direction intersecting the two cutting lines, opposite cutting line sides 
respectively approach the surfaces of the metal plates more than a center 
side. 
According to the connecting structure obtained by this method, against the 
displacement of the metal plates in the laminating direction, the cutting 
line side end portions of the projecting portion are respectively caught 
by the end portions of the metal plates so that the projecting portion is 
deformed in a direction to widen its width (the size between the two 
cutting lines). And still since the deformation becomes larger as the 
metal plates tend to displacement further, the sufficient overlap between 
the cutting end portions of the projecting portion and the cutting end 
portions or the metal plates in the laminating direction is obtained, and 
the slip out of the metal plates in the laminating direction is surely 
prevented. 
The invention provides a press mold used for connecting laminated metal 
plates with each other by forming two cutting lines independent of each 
other in the laminated metal plates, and at the same time, by forming a 
projecting portion by protruding a metal plate portion between the cutting 
lines by a step having a height larger than a thickness or the laminated 
metal plates in a laminating direction, the press mold is characterized in 
that an engagement convex portion formed on an engagement surface of a 
male mold with a female mold has a center projecting surface protruding 
with a larger size than a thickness of the metal plates, and a pair of 
slant surfaces slanted from the projecting surface towards the engagement 
surface. The engagement convex portion further includes two cutting lines 
formed in an edge shape formed by widthwise visible outlines or the pair 
of slant surfaces and visible outlines of the projecting surface which 
connect the widthwise visible outlines, and an interval between the 
cutting lines at the projecting surface of the male mold is made smaller 
than an interval of corresponding cutting lines of the female mold by a 
predetermined size (the size which allows to form an interval sufficient 
to cut by tension not by shearing, at the time of engagement of the male 
and female molds), and on at least one engagement surface of the male and 
female molds, there is formed with pressing convex portions at positions 
along or outside both the cutting lines located at an engagement concave 
portion or the female mold which receives the projecting surface at the 
time of engagement of both molds. 
According to this press mold, at the time of engagement or the engagement 
convex portion or the male mold with the engagement concave portion of the 
female mold with the laminated metal plates sandwiched therebetween, the 
laminated metal plates are sheared by the cutting lines of the slant 
surfaces, but with the cutting lines of the projecting surface portion, 
the laminated metal plates are extended in the laminating direction and 
cut by tension. As a result, the metal plate portion between the two 
cutting lines is protruded towards the laminating direction with a step 
having a height larger than the thickness of the laminated metal plates, 
so that this projecting portion projects to its highest position at its 
center portion from the surface of the metal plates from which the 
projecting portion is cut out, and this projecting portion has slant 
surface portions slanted towards the surface of the metal plates. 
When the engagement of the male and female molds further progresses, after 
the above-mentioned cutting, the laminated metal plates are pressed 
between the pressing convex portion and its opposing engagement surface 
(or mutually opposing convex portions with each other), and since the cut 
end portion of the rest of the laminated metal plates from which the 
center portion has been cut out is pressed and expanded in the 
above-mentioned gap, a sufficient overlap between the cut end portion of 
the projecting portion and the cut end of the rest of the laminated metal 
plates can be obtained. As a result, the displacement of the metal plates 
in the laminating direction is securely prevented. 
Accordingly, if this mold is used, by a press forming of one time, a 
connecting structure constituted by two cutting lines independent of each 
other, and a projecting portion formed by protruding a metal plate portion 
between the cutting lines by a step having a height larger than a 
thickness of the laminated metal plates, can be formed simply in a press 
work of one time resulting in a condition wherein the cut end portion of 
the laminated metal plates is collapsed and expanded. As a result, the 
connecting structure in which the metal plates are difficult to 
displacement in the laminating direction can be formed simply by a press 
work of one time. 
The invention is characterized in that the slant surfaces are slanted from 
the projecting surface towards the engagement surface with their skirt 
portions outwardly tapered. 
According to this press mold, since the projection lines of the widthwise 
visual lines of the slant surface onto the engagement surface form lines 
which taper radially from the projecting surface, the connecting method of 
the laminated metal plates can be easily performed by press forming of one 
time. 
Here the displacement of the metal plates in the laminating direction can 
be surely prevented. In particular, in addition to this, the displacement 
among the metal plates in every direction in the plane of the laminated 
metal plates can be surely prevented by the two cutting lines. 
Furthermore, since the strength of the rising portion of the projecting 
portion is maintained, the sure effect can be expected in the case where 
the laminated thickness is thick in particular. 
According to the method, the displacement among the metal plates in every 
direction in the plane of the laminated metal plates can be surely 
prevented by the two cutting lines. Furthermore, since the strength of the 
rising portion of the projecting portion is maintained, the sure effect 
can be expected in the case where the laminated thickness is thick in 
particular. 
According to the press mold, since it is possible to form the connecting 
structure in which the metal plates are difficult to slip out in the 
laminating direction simply by a press work of one time, the time required 
for the connecting work of the laminated metal plates can be reduced. In 
particular, it is possible to simply form by a press work of one time the 
ideal connecting structure in which the displacement or the metal plates, 
in the laminating direction is surely prevented, and the displacement 
among the metal plates in every direction is surely prevented by the two 
cutting lines, and the strength at the rising portion of the projecting 
portion is maintained.

BEST MODE FOR CARRYING OUT THE INVENTION 
Hereinafter, one mode for carrying out the present invention will be 
described with reference to the drawings. 
First, with reference to FIGS. 1 to 6, one mode for carrying out a press 
mold of the present invention will be described. In which, FIGS. 1 to 3 
show a male mold, and FIG. 1 is a plan view showing an engagement side 
with a female mold, FIG. 2 is its sectional view taken along the line 
A--A, and FIG. 3 is a sectional view taken along the line B--B. 
As shown in these figures, in the male mold 1, an engagement convex portion 
10 having a longitudinal section of a substantially trapezoid 
configuration is formed on a center portion or an engagement surface 11 
which is an end face of a mold column, and this engagement convex portion 
10 has a small circular projecting surface 12 protruding from the center 
of the engagement surface 11 by a height dimension of T, and has a pair of 
slant surfaces 13a slanted from the projecting surface 12 towards the 
engagement surface 11. Here, the height dimension of T is larger than a 
thickness of the laminated metal plates to be connected. Further, each of 
the slant surfaces 13a is slanted from a small circular arc 12a or the 
projecting surface 12 towards a large circular arc 11b on the engagement 
surface 11 while outwardly tapering the skirt portion thereof, and the 
pair of slant surfaces 13a are slanted to the sides 180 degrees apart from 
each other. 
Furthermore, the visible outlines of the slant surface 13a, in the plan 
view (FIG. 1), are constituted by radial portions 14a extending radially 
from the center 11a of a circle forming the engagement surface 11 at a 90 
degrees interval therebetween, and circular arc portions 14b respectively 
connecting the radial portions 14a with the ends or a small circular arc 
12a of the projecting surface 12. A cutting line is formed along a 
projecting line K consisting of the radial portions 14a, the circular arc 
portions 14b, and a circular arc 12b which is not continuous with the 
slant surfaces 13a of the projecting surface 12 (the line K is formed by 
connecting in the order the radial portion 14a, circular arc portion 14b, 
circular arc 12b, circular arc portion 14b, and radial portion 14a). 
FIGS. 4 to 6 show the female mold, in which FIG. 4 is a plan view showing 
an engagement surface side with the male mold, FIG. 5 is its sectional 
view taken along the line C--C, and FIG. 6 is its sectional view taken 
along the line D--D. 
As shown in these figures, the female mold 2 has an engagement surface 21 
formed by an end face of a mold column, and this engagement surface 21 is 
formed with an engagement concave portion 20 for receiving the engagement 
convex portion 10 of the male mold 1 described earlier. This engagement 
concave portion 20 has a sectional shape perpendicular to an axial 
direction of the column identical to a plan shape of the engagement convex 
portion 10, and it is formed as a hole penetrating in the axial direction 
and having no bottom surface. A cutting line is formed along a line H (a 
radial portion 24a, circular arc portion 24b, circular arc 22b, circular 
arc portion 24b, and radial portion 24a are connected in this order) on 
the engagement surface 21 corresponding to the projecting line K of the 
male mold 1. 
The radial portion 24a of the line H is formed so that no gap is caused in 
particular between this portion and the radial portion 14a of the 
projecting line K at the time of engagement with the male mold 1 (a normal 
gap required for shearing is formed). However, for the circular arc 
portion 24b and circular arc 22b, a diameter A (shown in FIG. 5) of a 
circle containing the circular arc 22b is made larger than a diameter a 
(shown in FIG. 2) of a circle containing the circular arc 12b of the male 
mold 1 by a predetermined dimension so that a predetermined gap (the gap 
required for tension cutting not for shearing) is formed from the circular 
arc portion 14b and circular arc 12b of the projecting line K. 
Furthermore, the female mold 2 has pressing convex portions 25 whose 
projecting surfaces are in parallel with the engagement surface 21, and an 
inner peripheral line 25a of the pressing convex portion 25, in the plan 
view, is formed by the circular arc portion 24b and circular arc 22b or 
the engagement concave portion 20, and an outer peripheral line 25b of the 
pressing convex portion 25 is formed by a circular arc having the same 
center 21a as that of the engagement surface 21 and positioned at the 
outside of the circular arc 22b by a small distance. Specifically, the 
pressing convex portions 25 are formed along both the cutting lines of the 
engagement concave portion 20 or the female mold 2. Also, a projecting 
height t of the pressing convex portions 25 from the engagement surface 21 
is set to be sufficiently smaller than the height T of the engagement 
convex portion 10 of the male mold 1; and these heights t and T, and a 
thickness L of the laminated metal plates are set to meet the relation of 
the following formula (1). 
EQU (T-t)&gt;L (1) 
When the laminated metal plates S are sandwiched between such an engagement 
surface 11 of the male mold 1 and the engagement surface 21 of the female 
mold 2, and the male mold 1 is inserted into the female mold 2 as shown in 
FIGS. 7 and 8a and 8b, a connecting structure 3 is formed, as shown in 
FIGS. 9a, 9b to 11, which is constituted by two cutting lines 3a, 3a 
independent of each other, and a projecting portion 3b formed by 
protruding a metal plate portion between these cutting lines 3a, 3a in the 
laminating direction by a step having a height larger than the thickness 
of the laminated metal plates. Furthermore, the projecting portion 3b is 
constituted by a center portion 32 which protrudes to its highest position 
from a metal plate surface V of the metal plates from which the projecting 
portion is cut out, and a pair of slant surface portions 33 which are 
slanted towards the surface V while forming outwardly tapering skirt 
portions. Here, FIGS. 9a, 9b correspond to plan views of the connecting 
structure 3, FIG. 10 corresponds to a sectional view taken along the line 
E--E in FIG. 9a, and FIG. 11 corresponds to a sectional view taken along 
the line F--F in FIG. 9a. 
FIG. 7 is a sectional view showing an inserting condition of the male mold 
1 into the female mold 2 in a plane along the section taken along the line 
B--B in FIG. 1, and the center portion 32 of the projecting portion 3b is 
formed by the projecting surface 12 of the male mold 1, and the slant 
surface portions 33 are formed by the slant surfaces 13a of the male mold 
1. 
Furthermore, as shown in FIG. 9a, since the slant surface forming portions 
34a of individual cutting lines 3a, which form each slant surface portion 
33, extend radially with an interval of 90 degrees therebetween from the 
center point 32A of the center portion 32 in the plan view, at each end of 
the cutting line 3a of the laminated metal plates, the end face 37 (shown 
in FIG. 10) of the laminated metal plates from which the projecting 
portion 3b is cut out, abuts against the end face of the slanted portion 
33, and thus, the displacement among the metal plates can be prevented in 
every direction in the plate plane of the laminated metal plates S. In 
other words, as shown in FIG. 9(b), since each slant surface forming 
portion 34a resists against the displacement in the direction shown by the 
arrow, the displacement in all the four directions can be prevented. 
FIGS. 8a, 8b respectively are sectional views showing a condition just 
before the insertion and an inserted condition of the male mold 1 into the 
female mold 2 in a plane along the section taken along the line A--A in 
FIG. 1, and FIG. 8(a) shows the condition just before the insertion and 
(b) shows the inserted condition. 
As shown in these figures, since an interval (dimension a) between the 
cutting lines P1, P1 in the projecting surface portion 12 of the 
engagement convex portion 10 of the male mold 1 is smaller than an 
interval (dimension A) between the cutting lines P2, P2 of the engagement 
concave portion 20 of the female mold 2, due to the advance of the 
engagement convex portion 10, opposite ends of the center portion 32 or 
the projecting portion are extended in the laminating direction and cut by 
tension within a gap M caused by a dimension difference (A-a) between the 
cutting lines P1, P2 of the male mold 1 and the female mold 2. As a 
result, the cut end portions 32a of the center portion 32 have a section 
having nicks and scratches which causes a large resistance in the 
displacement direction. In addition, after the engagement surface 11 of 
the male mold 1 reaches an upper surface S1 of the laminated metal plates 
S, the laminated metal plates S are pressed between an upper surface of 
the convex portion 25 of the female mold 2 and the engagement surface 11 
of the male mold 1. As a result, the cut end portion 36 of the laminated 
metal plates S from which the center portion 32 has been cut out is 
pressed and expanded within the gap M, and thus, a sufficient overlap 
portion between the cut end portion 32a and the cut end portion 36 is 
obtained so that the displacement in the laminating direction is surely 
prevented. 
In the method for carrying out the invention, there is formed with the 
connecting structure 3 (from FIG. 9a) including the circular center 
portion 32 and the pair of slant surface portions 33 slanted from the 
circular center portion with their skirt portions outwardly tapered, 
however, a plan shape of the connecting structure 3 may be as shown in 
FIGS. 12 to 14. 
In a connecting structure shown in FIG. 12, a center portion 32 is made in 
a square shape, and slant surface portions 33 are slanted from opposing 
two sides of the center portion with their skirt portions outwardly 
tapered, and slant surface forming portions 34a of the cutting lines 3a 
are extended radially from a center point 32A of the center portion 32. 
In a connecting structure shown in FIG. 13, each cutting line 3a is made to 
be a circular arc shape which is continuous by a center portion 32 and 
slant surface portions 33. This circular arc has tangents 01 and 02 which 
extend radially from a center point 32A of the center portion 32. 
In a connecting structure shown in FIG. 14, a pair of slant surface 
portions 33 of a projecting portion 3b has a shape in which the slant 
surface portions 33 are slanted from an elliptical center portion 32 
towards a laminated metal surface with their skirt portions 33 inwardly 
tapered, and slant surface forming portions 34a of each cutting line 3a 
are radial in the plane of the laminated metal plates. In this structure, 
similar to the mode for carrying out in FIGS. 9a, 9b and the cases in 
FIGS. 12 and 13, the displacement of the metal plates in every direction 
in the plane of the laminated metal plates is prevented. However, since 
the slant surface forming portions 34a are formed to be inwardly tapered 
from the center portion 32, in the case of the same length of the cutting 
lines 3a, the width of rising portions 38 of the slant surface portions 33 
become narrow, and the strength at the rising portions 38 of the 
projecting portion 3b becomes small. In contrast, as shown in FIGS. 9a, 
9b, 12 and 13, it is preferable that the slant surface forming portions 
34a of each cutting line 3a have the shape of outwardly tapering toward 
the outer side from the center portion 32, since the strength at the 
rising portions 38 of the projecting portion 3b is higher. 
Furthermore, the slant surface forming portions 34a of each cutting line 
3a, as shown in FIGS. 9a, 9b, 12 and 13, are not necessarily required to 
align with the lines which expand radially from the center point 32A of 
the center portion 32. If the slant surface forming portions 34a are 
formed so that the lines adjacent to each other in a circumferential 
direction are directed to two different directions in the plane of the 
laminated metal plates, the effect will be achieved to prevent the 
displacement among the metal plates in every direction in the plane of the 
laminated metal plates S. 
Furthermore, in the above-mentioned press mold, although the pressing 
convex portions 25 are formed on the engagement surface 21 of the female 
mold 2, this pressing convex portions 25 may be formed on corresponding 
positions on the engagement surface 11 of the male mold 1, or may be 
formed on both the male mold 1 and female mold 2. Furthermore, the 
pressing convex portions 25 are not required to be necessarily formed on 
the positions which coincide with both cutting lines P2, P2 of the 
engagement concave portion 20 of the female mold 2, but as shown in FIG. 
15, the pressing convex portions 25 may be formed outside both the cutting 
lines P2, P2 by providing concave portions 26 at positions which coincide 
with both the cutting lines P2, P2. By virtue of this, the laminated metal 
plates S, after being cut by tension in the laminating direction by the 
gap M mentioned above, are extended laterally in the concave portions 26 
to a larger extent than in the case of FIG. 8, and thus, it is possible to 
make the metal plates more difficult to displacement in the laminating 
direction. 
Furthermore, as shown in FIG. 16, when a section of a projecting surface 
portion of the male mold 1 between cutting lines P1, P1 is made to have a 
shape protruding more at the center side than both the cutting line P1 
sides, and as shown in FIG. 17, when the projecting portion 3b is pressed 
and deformed so that, in the section of the projecting portion 3b along 
the line F--F in FIG. 9a, both the cutting line 3a sides approach more to 
the surfaces of the metal plates S than the center side of the projecting 
portion 3b, the projecting portion 3b is deformed to outwardly taper to 
the width of the dimension between the two cutting lines 3a and against 
the displacement the metal plates in the laminated direction. That is, 
when the metal plates intend to move away in the displacement direction, 
the end portions of the cutting line 3a sides or the projecting portion 3b 
are caught by the end portions or the metal plate sides, so that the 
larger the force exerted in the displacement direction, the more becomes 
the deformation in the direction to expand the width of the projecting 
portion 3b. As a result, since the cut end of the projecting portion 3b is 
overlapped with the cut end portion or the metal plates in the laminating 
direction, the displacement or the metal plates in the laminating 
direction is surely prevented. 
FIG. 18 is a plan view showing an example of connecting a metal gasket or a 
laminated structure by the method in the above-mentioned mode for carrying 
out the invention. In this example, similar to the connection by the 
conventional eyelet hole, the connection structure 3 in the 
above-mentioned mode for carrying out the invention is formed in a 
connecting portion 41 of a tongue shape which is formed at an outer 
peripheral edge. However, since this connection structure 3 protrudes to 
only one surface side different from the conventional eyelet hole, such a 
connecting portion 41 is not necessarily required to be formed at the 
outer peripheral edge, and thus, the shape of the outer peripheral edge of 
the metal gasket can be made simple. 
Specifically, in the case where there is no need to communicate water holes 
or a cylinder head and a cylinder block with each other by the metal 
gasket, and since the water hole is not opened in the cylinder head, the 
connecting structure 3 as mentioned above can be formed at that position. 
Furthermore, even when a cast escaping hole for the purpose or reducing 
weight is formed in a joint surface or the cylinder head or cylinder block 
with the metal gasket, and since there is no need to provide a hole in the 
metal gasket corresponding thereto, the connecting structure 3 as 
mentioned above may be disposed at that position, and the projecting 
portion 3b may be protruded towards the cast escaping hole.