Metal plate bonding method

Abstract

The object of this invention is to provide a method for joining metal plates that can join dissimilar materials with high strength and precision without requiring special bonding members. [Solution] The metal plate joining method according to the present invention is a method of laminating and joining a first metal plate and a second metal plate, characterized in that a cylindrical recess is formed by applying pressure perpendicular to the surface of the first metal plate at at least one location on the first metal plate and a cylindrical dowel (protrusion) is formed on the surface opposite to the recess, a through hole approximately equal in diameter to the dowel is formed on the second metal plate, the dowel is inserted into the through hole, and then the first metal plate and the second metal plate are joined by applying pressure around the through hole to cause the material of the second metal plate around the through hole to plastically flow toward the dowel.

Description

Technical Field

[0005]

[0001] The present invention relates to a method for bonding metal plates that can firmly bond even different materials.

Background Art

[0002] Metal plates are used in many fields, and many types of bonding methods are known. Representative bonding methods include bolts and nuts, burring caulking, rivets, etc. For example, in the case of bolts and nuts disclosed in Patent Document 1, there is a problem that two types of bonding materials are required and it takes time for bonding.

[0003] There is also a method of physically locking two materials without using a bonding member. Patent Document 2 discloses a technique of a type of burring caulking. A first plate material with a caulking portion protruding formed by burring, and a second plate material with an insertion hole into which the caulking portion is inserted formed in advance, are overlapped by inserting the caulking portion into the insertion hole, and the tip side of the caulking portion is caulked so as to be folded back to the periphery of the insertion hole to join the first plate material and the second plate material. This technique has the advantage that bonding materials such as bolts and nuts are not required, but cracks are likely to occur in the peripheral portion because the periphery of the caulking portion is widened for caulking, resulting in defects. Also, there is a drawback that the area of the bonding portion is large. Furthermore, it is difficult to bond materials with a thick plate thickness by this method. <00,00014> In the case of a rivet, it is a method of pushing the rivet into a soft material to form an anchor, but the amount of the anchor is small, and a gap is likely to occur between the soft material and the rivet, or the tightening force between the soft material and the rivet is weak, resulting in low strength.

[0005] Patent Document 3 discloses a bonding structure and bonding apparatus for metal members utilizing plastic flow bonding. This technology describes a method and apparatus for bonding a first metal member having an annular portion to a second metal member having an axial portion using a restraining ring. While high-strength and high-precision metallic bonding can be achieved by utilizing plastic flow bonding, this technology cannot be directly applied to bonding metal plate-shaped members. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-130238 [Patent Document 2] Japanese Patent Publication No. 2005-279650 [Patent Document 3] Republished Patent Publication No. 2011 / 118219 [Overview of the project] [Problems that the invention aims to solve]

[0007] In view of the above-mentioned problems, the present invention aims to provide a metal plate joining method that can join dissimilar materials with high strength and precision without requiring special joining members. [Means for solving the problem]

[0008] To solve the above-mentioned problems, the present invention provides a method for joining metal plates by laminating a first metal plate and a second metal plate, characterized in that a cylindrical recess is formed on the first metal plate by applying pressure perpendicular to the surface of the first metal plate at at least one location on the first metal plate, and a cylindrical dowel (protrusion) is formed on the opposite surface of the recess, a through hole approximately equal in diameter to the dowel is formed on the second metal plate, the dowel is inserted into the through hole, and then the first metal plate and the second metal plate are joined by applying pressure around the through hole to cause plastic flow of the material of the second metal plate around the through hole toward the dowel. Preferably, the first metal plate has a higher hardness than the second metal plate, and forming a groove around the tip of the dowel is also very effective.

[0009] The metal plate joining method according to the present invention is a method of laminating and joining a first metal plate and a second metal plate, characterized in that a cylindrical recess is formed by applying pressure perpendicular to the surface of the first metal plate at at least one location on the first metal plate and forming a cylindrical dowel (protrusion) on the opposite surface of the recess, a through hole approximately equal in diameter to the dowel is formed on the second metal plate, the dowel is inserted into the through hole, and then at least the peripheral portion of the tip of the dowel inserted into the through hole is pressurized to cause the dowel member of the first metal plate to plastically flow toward the wall of the through hole in the second metal plate, thereby joining the first metal plate and the second metal plate. Preferably, the second metal plate has a higher hardness than the first metal plate, and it is also very effective to form a groove around the wall of the through hole in the second metal plate. [Effects of the Invention]

[0010] The metal plate joining method according to the present invention involves inserting a dowel formed in one metal plate into a through-hole formed in the other metal plate, and then applying pressure around the through-hole or the tip of the dowel in the lower-hardness metal plate using a punch or the like to push it in. This causes the material of the pressurized metal plate to flow into the groove provided in the dowel or the wall of the through-hole in the higher-hardness metal plate, and the resistance of the shear deformation of that material can be used to create a strong bond. Furthermore, because the joining part of the metal plate joining method according to the present invention has no protrusions, it is expected to be used in many fields. It should be noted that, as is common with mechanical joining methods, it is possible to join laminates even if the materials are dissimilar. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view of metal plates joined by one embodiment of the metal plate joining method according to the present invention. [Figure 2] Figure 1 is a process diagram illustrating an embodiment of the metal plate joining method. Figure 2(a) is a cross-sectional view illustrating the process of forming a dowel on the first metal plate, Figure 2(b) is a partial cross-sectional view showing the state of the first metal plate after dowel formation, and Figure 2(c) is a cross-sectional view showing the state immediately after joining the first and second metal plates. [Figure 3] This is a cross-sectional view of metal plates joined according to another embodiment of the present invention. [Figure 4] This is a cross-sectional view showing the state immediately after joining the first metal plate and the second metal plate using the metal plate joining method shown in Figure 3. [Figure 5] This is a cross-sectional view showing the state in which the first metal plate and the second metal plate are joined together according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0012] Preferred embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows a cross-sectional view of a state in which the metal plates have been joined according to the first embodiment of the metal plate joining method of the present invention. A cylindrical recess 11 is formed in the first metal plate 10, and a cylindrical dowel 12 is formed as a protrusion on the opposite side. A groove 13 is formed around the tip of the dowel 12. The dowel 12 is also inserted into a through hole 21 formed in the second metal plate 20. A punch mark 22 is formed around the through hole 21 in the second metal plate 20. By inserting the dowel 12 on the first metal plate 10 into the through hole 21 in the second metal plate 20 and applying pressure around the through hole 21 in the second metal plate 20 with a punch or the like, the material around the through hole 21 in the second metal plate 20 plastically flows into the groove 13 of the dowel 12 on the first metal plate 10, thereby joining the first metal plate 10 and the second metal plate 20.

[0013] The manufacturing process for this embodiment will be explained with reference to Figure 2. Figure 2(a) shows the first step. The first metal plate 10 is sandwiched between the lower presser foot 31 and the upper presser foot 32. The lower presser foot 31 has a punch operating hole 35, and the upper presser foot 32 also has a dowel forming hole 33 at the same position. In this state, by raising the dowel forming punch 34 from below through the punch operating hole 35, a cylindrical recess 11 is formed on the lower surface of the first metal plate 10, and the component in this part moves upward, forming a cylindrical dowel 12 protruding from the first metal plate 10 inside the dowel forming hole 33.

[0014] Figure 2(b) shows a partial cross-sectional view of the first metal plate 10 after the first step. The lower part of this figure remains as it was when the dowel 12 was formed in the first step, while the upper part is a front view in which a groove 13 has been formed around the tip of the dowel 12.

[0015] Figure 2(c) is a cross-sectional view showing the state immediately after the first metal plate 10 and the second metal plate 20 are joined in the second step. The first metal plate 10 is placed on a support base 40. A projection 41 is formed on the support base 40 and is configured to fit into a recess 11 on the first metal plate 10. Furthermore, the dowels 12 on the first metal plate 10 are stacked so that they fit into the through holes 21 of the second metal plate 20, and then the area around the through holes 21 of the second metal plate 20 is pressed from above with a joining punch 50. This forms punch marks 22 on the second metal plate 20. At this time, the material around the through holes 21 of the second metal plate 20 plastically flows into the grooves 13 of the dowels 12 on the first metal plate 10, thereby joining the first metal plate 10 and the second metal plate 20.

[0016] In this embodiment, a 2mm thick steel plate (SPCE) was used as the first metal plate 10, and a 1.6mm thick aluminum plate (A5052) was used as the second metal plate 20.

[0017] A feature of the metal plate joining method according to the present invention, as shown in the above embodiment, is that it does not require special joining members such as rivets or plugs, and two metal plates can be laminated and joined. Furthermore, by applying pressure to the material around the through hole 21 of the second metal plate 20 with the projection 52 provided at the tip of the joining punch 50, this material is forced to flow into the groove 13 provided in the dowel 12 on the first metal plate 10 and pushed in, thereby increasing the resistance to shear deformation and firmly joining the two metal plates. In addition, the material of the second metal plate 20 is pressed with high pressure on the surface of the dowel 12 other than the groove 13, and this pressure has the characteristic of being retained as residual stress even after the joining punch 50 is removed from the second metal plate 20, and the frictional resistance force of this tightening is added to the joining force, resulting in a stronger bond. If the required joining strength is not high, it is also possible to omit the formation of the groove 13 on the dowel 12 and join with a simple cylindrical dowel.

[0018] Here, the shape of the through-hole of the metal plate used for joining will be described. The hole can be formed by cutting such as drilling, laser processing, electrical discharge machining, etc., and the direction of the hole is generally perpendicular to the surface of the metal plate. However, press working is often used for mass-produced products. In press working, the dimension of the hole entrance is approximately equal to the punch diameter, and the dimension of the hole exit side (die side) is approximately equal to the die dimension. On the other hand, the die hole has a larger clearance with respect to the diameter dimension of the punch. In the processing by precision shearing, since the clearance is small (about 0.5 to 2% of the plate thickness), the hole is almost perpendicular to the plate surface.

[0019] Next, a second embodiment of the metal plate joining method according to the present invention will be described based on FIG. 3. FIG. 3 is a cross-sectional view of a joined state by the second embodiment of the metal plate joining method of the present invention. A cylindrical recess 11 is formed in the first metal plate 10, and a cylindrical dowel 12 is formed as a convex portion on the opposite side. The dowel 12 is inserted into a through-hole 21 formed on the second metal plate 20. A groove portion 23 is formed along the circumference of the hole in a portion of the inner surface of the through-hole 21 close to the upper surface of the second metal plate 20. A punch mark 14 is formed on the upper surface of the dowel 12 of the first metal plate 10. By inserting the dowel 12 on the first metal plate 10 into the through-hole 21 of the second metal plate 20 and pressurizing the periphery of the dowel 12 of the first metal plate 10 with a punch or the like, the member of the dowel 12 plastically flows into the groove portion 23 formed in the through-hole 21 on the second metal plate 20 and enters, whereby the first metal plate 10 and the second metal plate 20 are joined.

[0020] The manufacturing process of this embodiment will be described based on FIG. 4. FIG. 4 is a cross-sectional view showing the state immediately after the first metal plate 10 and the second metal plate 20 are joined. Place the first metal plate 10 on the receiving base 40. On the receiving base 40, a protruding portion 41 is formed, which is configured to fit into the recess 11 on the first metal plate 10. Further, after laminating so that the dowel 12 on the first metal plate 10 fits into the through hole 21 of the second metal plate 20, the periphery of the dowel 12 of the first metal plate 10 is pressed from above by the joining punch 50. As a result, a punch mark 14 is formed on the dowel 12. At this time, the members near the punch mark 14 of the dowel 12 plastically flow into the groove portion 23 on the inner surface of the through hole 21 of the second metal plate 20, thereby joining the first metal plate 10 and the second metal plate 20.

[0021] In this embodiment, an aluminum plate (A5052) with a thickness of 1.6 mm was used as the first metal plate 10, and a steel plate (SPCE) with a thickness of 2 mm was used as the second metal plate 20.

[0022] FIG. 5 shows a cross-sectional view according to a third embodiment of the metal plate joining method according to the present invention. The materials of the first metal plate and the second metal plate are the same as those in the second embodiment above. The difference is that the height of the dowel 12 of the first metal plate 10 is smaller than the thickness of the second metal plate 20. Also, in this embodiment, the entire upper surface of the dowel is pressed by the joining punch. As a result, the members of the dowel 12 plastically flow into the groove portion 23 on the inner surface of the through hole 21 of the second metal plate 20, thereby joining the first metal plate 10 and the second metal plate 20. Since the groove portion 23 on the inner surface of the through hole 21 can be formed using a cam mechanism or the like, when the dowel 12 is short, it is necessary to move the position of the groove portion 23 on the inner surface of the through hole 21 downward.

Explanation of Reference Numerals

[0023] 10 First metal plate 11 Recess 12 Dowel 13 Groove portion 14 Punch mark 15 Upper surface of dowel 20 Second metal plate 21 Through hole 22 punch marks 23 Groove 31 Lower presser foot 32 Upper presser foot 33 Dowel forming holes 34 Dowel forming punch 40 support stand 41 Protrusion 50 Joining punches 51 Cavity 52 Protrusion

Claims

1. A method for laminating and joining a first metal plate and a second metal plate, characterized in that a cylindrical recess is formed on the first metal plate by applying pressure perpendicular to the surface of the first metal plate at at least one location on the first metal plate, a cylindrical dowel (protrusion) is formed on the surface opposite to the recess, a through hole substantially equal to the diameter of the dowel is formed on the second metal plate, the dowel is inserted into the through hole, and then the first metal plate and the second metal plate are joined by applying pressure around the through hole to cause plastic flow of the material of the second metal plate around the through hole toward the dowel.

2. The metal plate bonding method according to claim 1, characterized in that the first metal plate has a higher hardness than the second metal plate.

3. The metal plate joining method according to either claim 1 or 2, characterized in that a groove is formed around the tip of the dowel.

4. A method for laminating and joining a first metal plate and a second metal plate, characterized in that a cylindrical recess is formed on the first metal plate by applying pressure perpendicular to the surface of the first metal plate at at least one location on the first metal plate, and a cylindrical dowel (protrusion) is formed on the opposite surface of the recess, a through hole substantially equal to the diameter of the dowel is formed on the second metal plate, the dowel is inserted into the through hole, and then at least the peripheral portion of the tip of the dowel inserted into the through hole is pressurized to cause the dowel member of the first metal plate to plastically flow toward the wall of the through hole in the second metal plate, thereby joining the first metal plate and the second metal plate.

5. The metal plate bonding method according to claim 4, characterized in that the second metal plate has a higher hardness than the first metal plate.

6. The metal plate joining method according to either 4 or 5, characterized in that a groove is formed around the through-hole wall portion of the second metal plate.

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