JPS6113889B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a leakproof sheet metal bonding structure for permanently bonding two superimposed sheet metal sheets. It is related to

More specifically, this invention provides: A. a cap-shaped first protrusion provided on a first of the thin metal plates, which is integral with and continuous with the first thin metal plate; B. a cap-shaped second protrusion provided on a second of the thin metal plates; , a second protrusion formed by a continuous, hole-free, unbroken metal part that is integral with the second thin metal plate, and a. The first protrusion and the second protrusion are fitted into the first protrusion, and the free ends of the first protrusion and the second protrusion extend outward in the radial direction over the entire circumference and are fitted into each other. The present invention relates to a bonding structure of thin metal plates that are mechanically engaged with each other. Prior Art and Its Problems Such a bonding structure of thin metal plates is disclosed in, for example, U.S. Patent No.
Although it is already known as disclosed in Specification No. 3338463 (corresponding to Japanese Patent Publication No. 41-5589),
The conventional type was not suitable for applications where a large force was applied in the direction of separating the two metal sheets.

In other words, in the conventional joining structure, as disclosed in the above-mentioned US patent specification, a cap-shaped protrusion is formed on each of two thin metal plates to be joined in a separate process, and then both protrusions are mutually connected. After that, a plunger-shaped anvil is fitted onto both protrusions, and a punch is applied from the opposite side of the anvil to mechanically engage the free ends of both protrusions with each other. The first protrusion on the first thin metal plate, which is the outer side in the protrusion-fitted state, is partially crushed to reduce its height after forming. A process is performed in which the second protrusion on the inner second thin metal plate is fitted onto the first protrusion so that the free ends of both protrusions are engaged with each other. The plunger-like anvil used in the process is a spring-loaded type that is biased by a spring to move in the direction of both protrusions, and by crushing both protrusions, that is, by bending the peripheral wall on the side of the protrusions, the height of both protrusions is reduced. This causes the free ends of both projections to expand radially outward, thereby forming an interengaging enlarged portion of the free ends of the projections.

The mechanical mutual engagement formed by crushing the pre-formed protrusion and bending the side peripheral wall to expand the free end in the outer circumferential direction is such that the free end of the second protrusion located inside The degree of engagement is relatively small since the first protrusion located on the outside is engaged in a state in which it slightly protrudes outward in the radial direction from the inner surface of the side circumferential wall. Therefore, when the conventional coupling structure is used in applications where a large force is applied in the direction of separating both thin metal plates, even a slight deformation of the free end of the protrusion can cause the coupling to come undone. Moreover, by applying bending deformation or buckling deformation due to crushing to the side circumferential wall of the cap-like projection of the thin metal plate, the strength of the thin metal plate itself at the deformed portion of the side circumferential wall, which becomes a stress concentration point, is considerably weakened. Problems of the Invention Therefore, the present invention provides a joining structure of thin metal plates as mentioned at the beginning, in which the cap-like protrusions on both thin metal plates are firmly engaged with each other at their free ends, and the two thin metal plates are bonded together. It is an object of the present invention to provide a new joint structure that can be used without any problems even in applications where a large force is applied in the direction of separation, and that also ensures a high strength of the thin metal plates themselves at the joint portion. Structure and Effects of the Invention In order to solve the problems of the invention, the invention takes the following technical measures.

That is, the thin metal plate bonding structure of the present invention is a bonding structure as described at the beginning, and c) the first protrusion and the second protrusion are connected to the first thin metal plate and the second metal plate, respectively. A side peripheral wall protruding almost perpendicularly from the thin plate, and the first thin metal plate and the second thin metal plate are substantially parallel to each other and are compressed and extruded in the thickness direction so as to bulge outward in the radial direction. a substantially flat end wall having a substantially flat end wall;
It is arranged at the intersection of the side circumferential wall and the end wall, and d the end wall of the second protrusion is pushed outward in the radial direction to a position beyond the side circumferential wall of the first protrusion. It is characterized by:

Such a bonding structure is as illustrated in FIG. 1, in which b represents the first metal thin plate and a represents the second metal thin plate.
It is a thin metal plate. The first thin metal plate b has a cap-shaped first protrusion 100b, the second thin metal plate a has a cap-shaped second protrusion 100a, and the second protrusion 100a is connected to the first protrusion. 100b. Each protrusion 100b, 100a is formed from a thin metal plate b, a, respectively.
integral with and continuous with no holes or breaks. Both protrusions 100b, 100a extend over the entire circumferential direction at their free ends;
100a, and therefore both metal sheets b, a
It is enlarged at section 62 to form a mechanical fit that makes it impossible to separate.

Each protrusion 100b, 100a is a side peripheral wall 101b, 10 projecting almost perpendicularly from the thin metal plate b, a.
1a, and substantially flat end walls 102b, 102a which are extruded substantially parallel to the metal sheets b, a and extend radially outwardly, and the enlarged portion 62 is the side peripheral wall 101
b, 101a and the end walls 102b, 102a. As a result of extrusion molding, the end walls 102b and 102a are thinner than the original thin metal plates b and a.

In particular, the end wall 102a of the second projection 100a is pushed radially outward to a position beyond the side peripheral wall 101b of the first projection 100b by a distance α.

Since the metal thin plate joining structure according to the present invention is configured as described above, both the metal thin plates b and a are very firmly engaged in the direction in which they are separated from each other. End wall 102 of second protrusion 100a
a extends outward beyond the position of the side peripheral wall 101b of the first protrusion 100b. If a force is applied in the direction of separation as indicated by arrow F in the figure, the second protrusion 1
Rather than being deformed such that it is pulled out of the first protrusion 100b, the first protrusion 100b applies a force in a direction such that the first protrusion 100b is deformed such that the first protrusion 100b is more firmly engaged. Let it work. The same holds true when a force in the direction of separation is applied to the first thin metal plate b while the position of the second thin metal plate a is fixed.

In this way, the thin metal plate bonding structure of the present invention is
Cap-shaped protrusions 100b, 100 provided on two metal thin plates b, a to be joined and fitted together
By extruding the end walls 102b and 102a of a to make them extend outward in the radial direction, the degree of mechanical mutual engagement between the thin metal plates b and a is greatly increased. It can also be used without any problems in applications where a large force is applied in the direction of separating thin metal plates.

Further, the bonding structure of the thin metal plates of the present invention is such that the cap-like projections 100b and 100a on both the thin metal plates b and a are
The mechanical mutual engagement between the protrusions 100b and 1
The end walls 102b, 102a of 00a are formed by extruding them outward in the radial direction to form enlarged parts, and the enlarged parts are mutually engaged with each other by the flow of the metal material of the end walls 102b, 102a. As a result of extruding the end walls 102b, 102a, the side peripheral walls 101 of the protrusions 100b, 100a
Although there is some curvature in b and 101a, there are no parts that are distorted at stress concentration points such as those caused by bending deformation or buckling deformation due to crushing, and the thin metal plate itself at the joint part does not exist. The strength will also be ensured.

The most common materials to which a bonding structure according to the invention may be applied are sheets of aluminum, galvanized iron, brass, steel, etc., painted or unpainted. ,Believable. The invention is particularly suitable for joining dissimilar materials that cannot be welded together. Embodiment As described above, FIG. 1 shows an example of a bonding structure of thin metal plates according to the present invention.

In the coupling structure shown in FIG. 1, the cap-shaped first and second protrusions 100b and 100a are formed to have a circular cross-sectional shape.

An exemplary apparatus and method for obtaining the bonded structure of thin metal sheets illustrated in FIG. 1 will now be described with reference to FIGS. 2-8.

The above device includes a die device 10 and a punch device 1.
2.

The punch device 12 is of a conventional construction and includes a punch body 14 on which a circular punch 16 is mounted and has a threaded portion 18 for threadingly supporting a stripper holder 20. A stripper 22 is provided within the retainer 20 and biased by a coil spring 24 to the stripping position shown in FIG. punch 16
It is desirable that the tip have a flat tip with a slight rounding at the edge as shown in FIG.

The die device 10 has a cylindrical die body 26.
The die body 26 is provided with a lower leg of a conventional C-form clamping device used in standard presses or the lower leg of a small press, such as the type of press disclosed in U.S. Pat. No. 3,730,044. Support structure 2 which can be any die support part
8 and is supported as usual. The die body 26 is provided at its upper end in the drawing with an integral projection 30 from which four shoulders, each designated by the reference numeral 32, extend from opposite sides. The die body 26 is centrally bored and has a hole portion 34 at its upper end in which is disposed (by press fit or the like) a stiffening pin 36 which serves as an anvil or lower die member.

A die portion 38 is rotatably supported on each side of the die body 26 by a fulcrum pin 40 inserted through a through hole 42 . Each die part 3
8 has a substantially T-shape in side view and is provided with two shoulders 44 that can engage with two shoulders 32 on the die body 26, from which the vertical The force in the direction is the die body 2
6 and is not absorbed by pin 40. Each die portion 38 is lightened by being notched at portion 45 to facilitate limited pivoting movement. The die portion 38 is supported for rotation between the position shown in FIG. 2 and the position shown in FIG. 3, and includes an integral leg extending downwardly relative to the die portion 38. A coil spring 46 acting between 48 normally maintains it in the closed position shown in FIG. The coil spring 46 is passed through a suitable hole 50 passing through the projection 30.

When the die portions 38 are in the closed position shown in FIG. lies within the plane. In this example, each die portion 38 has a respective semicircular groove 56 that completes a circle centered on the face 54.
A groove 56 is provided which forms an opening corresponding to the shape of the punch 16 when the die portion 38 is in the closed position. The downward force applied to the die portions 38 by the punch 16 acting on the material to be bonded does not cause the die portions 38 to pivot away from each other. This is because the rotation axis given by the fulcrum pin 40 is located outward from the periphery of the opening formed by the groove 56. Therefore, any downward force exerted by punch 16 on die portion 38 will act to close the die rather than open it. In this embodiment, the periphery of the opening formed by the groove 56 is provided with a reference numeral 58 (second,
It should be chamfered as shown in Figure 8).

In operation, the illustrated device is initially in the position shown in FIG. In order to join two metal sheets, the metal sheets are first stacked face-to-face and then the lower side of the metal sheet assembly is diced into the apparatus shown in FIG. It is inserted over the surface 52 of the section 38. Then, a press (or some other device) is operated to move the punch 16 downward in the drawing toward the metal sheets a, b and the die device 10.
When the engagement between the punch 16 and the sheet metal occurs, the sheet metal moves downwardly towards the anvil 3, indicated by reference numeral 60.
6, and protrusions are formed on both thin metal plates. A chamfer or roundness 58 is provided on the periphery of the opening formed by the groove 56, and a gap (clearance) is provided between the opening and the punch 16.
Since this is provided, the thin metal plate will not break or shear. When the punch 16 approaches the anvil 36 to a distance less than the sum of the initial thicknesses of the metal sheets a and b, a sideways extrusion or extrusion of the metal occurs, and the fit relationship on the metal sheets a and b occurs. Lateral enlargements, as indicated by the reference numeral 62 in FIG. 8, are formed in both protrusions at , so that a mechanical interengagement between the metal sheets a and b is formed.
The die portion 38 is urged laterally and outwardly by the above-described sideways extrusion of the thin plate material, and the die portion 38
pivot outwards as clearly shown in FIGS. 3 and 8. Now that a strong, permanent and leak-tight bonding structure has been formed, the punch 16 is then retracted to the position shown in FIG. 2 and the material to be bonded is removed. It should be noted that in this device only the punch 16 is actuated and the anvil 36 remains stationary. When the material to be bonded is removed, the die portion 38 is held by the coil spring 46.
is returned to the closed position shown in FIG.

In the device described above, shearing or breaking of the metal sheet is avoided by providing the roundness 58 and by providing a suitable gap between the punch 16 and the opening formed by the groove 56. The above void is
It is desirable to have a uniform width throughout the circumference. Although the applicant has not conducted any tests to optimize the relationship between the dimensions of each part, the following is a formula for determining dimensions that has been found to give very satisfactory results.

P = 2 (M ₁ + M ₂ ) (+/-20%) D = P + 0.8 (M ₁ + M ₂ ) T = 0.2 {1.2 (M ₁ + M ₂ )} Where, P = Punch diameter D = Die Diameter M ₁ = Upper metal thickness M ₂ = Lower metal thickness T = Total metal thickness at the bond center. We have found these relationships to be a satisfactory starting point. Once the punch diameter is selected and the device is assembled and tested, the lower anvil height is adjusted using a standard "shut height" adjustment on a conventional compact press and C-frame. By adjusting the distance between the underside of the punch and the anvil when the press is at the end of its downward stroke, satisfactory results can be obtained for the materials to be joined.

Although the apparatus described above uses a circular punch, punches of other shapes may also be used depending on the application and required strength. For example, FIG. 9 illustrates four different punch shapes that can be used. In FIG. 9a, the die portion 38a is
Three circular through holes (circular openings) 64 are provided for applications where more than a single circular connection is required for either rotation prevention or strength reasons. In FIG. 9b, the die portion 38b
has a diamond-shaped through hole or aperture 66 which provides a bond of strength comparable to that provided by the previously described devices, but which produces a more anti-rotation bond. In FIG. 9c, the die portion 38c is
A triangular shaped aperture 68 which would give a result similar to that given by the diamond shaped aperture 66 described above.
have. In FIG. 9d, die portion 38d has an oblong opening 70 that provides a relatively large bond with high strength and high anti-rotation. Regardless of the shape of such a punch or die partial opening, the inner wall of the tensioned portion of the upper sheet metal is generally cylindrical.

FIG. 10 shows a general-purpose die body 26a, which has a second
8, but having a plurality of parallel vertical holes 72, 74, and 76 for receiving hardened anvil pins 78, 80, and 82, respectively, by press fit; It is provided. In applications where a single circular connection is sufficient, pins 78 and 82
can be removed from the die body 26a to reduce energy consumption. On the other hand, if greater strength or anti-rotation properties are desired, one or two anvil pins may be added and inserted into the corresponding holes.
May increase binding capacity. The die portion attached to die body 26a will have a top surface shape similar to die portion 38a shown in FIG. 9a, with openings 64 designed to cooperate with anvil pins 78, 80 and 82. .

FIG. 11 shows the lower portion of a punch that can be used with the universal die body shown in FIG. Punch body 84, which may otherwise be conventionally constructed, includes anvil or anvil pin 78 of FIG. 10 in the same manner as punch 16 cooperates with anvil 36 in the example apparatus illustrated in FIGS. , 80 and 82 are provided. A suitable through hole 92 is provided in the punch body 84.
can be provided to allow removal of the punches or pins 86, 88, 90 if it is desired to replace or reduce their number for a special application. The punch pin and anvil can have cross-sectional shapes other than circular if desired.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a bonding structure of thin metal plates according to the present invention. FIG. 2 is a partial front view of an example of an apparatus for obtaining the joining structure of the thin metal plates shown in FIG. 1, with the punch in the retracted position. FIG. 3 is a partial front view of the apparatus shown in FIG. 2 with the punch in the advanced position; FIG. 4 is a plan view taken approximately along the - line in FIG. 2. Figure 5 shows - of Figure 4.
FIG. 3 is a partial cross-sectional view taken approximately along a line. FIG. 6 is a partial cross-sectional view taken approximately along the - line in FIG. 4. Figure 7 shows the second-
FIG. 7 is a perspective view of a die body in the apparatus shown in FIG. 6; FIG. 8 is an enlarged partial cross-sectional view illustrating the operation of the device upon completion of formation of the bonding structure.
FIGS. 9a, 9b, 9c and 9d are plan views showing the main parts of a die for forming a plurality of types of bonds of different shapes. FIG. 10 is a partially exploded perspective view showing a versatile die device that can be used to implement the present invention. FIG. 11 is a partial front view of a general-purpose punching device suitable for use with the die device shown in FIG. 10. b...First metal thin plate, a...Second metal thin plate, 100b...First protrusion, 100a...Second
Projections, 101b, 101a...Side peripheral wall, 102
b, 102a... End wall, 62... Enlarged portion.

Claims (1)

[Scope of Claims] 1. A leak-proof bonding structure for permanently fixing two superimposed thin metal plates, A. A cap provided on a first of the thin metal plates; a first protrusion of a shape, the first protrusion being formed by a continuous, hole-free and unbroken metal portion of the first thin metal plate; B. the metal; A cap-shaped second protrusion provided on a second thin metal plate of the thin plates, a metal portion that is integral with the second thin metal plate, is continuous, has no holes, and is not broken. a second protrusion formed in this way; a) the second protrusion is fitted into the first protrusion; and b the first protrusion and the second protrusion. is a coupling structure in which the free end portions extend all around the circumference and are mechanically engaged with each other by fitting the enlarged portions so as to bulge outward in the radial direction, c. A side peripheral wall in which the first protrusion and the second protrusion respectively protrude substantially perpendicularly from the first thin metal plate and the second thin metal plate, and the first protrusion and the second protrusion are substantially perpendicular to the first thin metal plate and the second thin metal plate. and substantially flat end walls which are parallel and extruded in compression in the thickness direction so as to bulge radially outwardly, the first protrusion and the second protrusion as described above. The enlarged part of the protrusion is
It is broken at the intersection of the side circumferential wall and the end wall, and d. The end wall of the second protrusion is pushed outward in the radial direction to a position beyond the side circumferential wall of the first protrusion. A bonded structure of thin metal sheets.