JP2013099776A - Cold pressure welding construction method and cold pressure welding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold pressure welding construction method which prevents a material to be joined from warping up due to pressurization thereto, and also promotes plastic deformation of a joined interface of the superposed materials to be joined to secure high joint strength, and to provide a cold pressure welding apparatus.SOLUTION: The cold pressure welding construction method includes steps of: squeezing the materials 7a, 7b to be joined that are superposed on a die 6 by pressurizing with a projection 11 of a punch 10; holding the circumference of the pressurized part by a shoulder part 12 of the punch overhanging outward in a direction perpendicular to the proceeding direction thereof from a proximal part of the projection, after squeezing part of the materials be joined by the projection; and completing the squeezing operation by the punch 10 while a gap G is left in a region that is surrounded by an inner corner part 11a defined by the projection 11 and the shoulder part 12 of the punch 10, and the upper material 7a to be joined.

Description

  The present invention relates to a cold welding method and a cold welding apparatus.

  In the cold welding method, at a temperature lower than the recrystallization temperature of the materials to be joined, the overlapped materials to be welded are pressed from both end surfaces to be plastically deformed, and the oxide layer or surface treatment layer at the joining interface of these materials to be joined. This is a method of dividing (plating layer or the like) and metal bonding (diffusion bonding) of the new surfaces generated.

  The cold welding method is suitable for joining soft metals such as aluminum and copper. For example, when joining terminals of a laminated battery of an automobile, a plurality of terminal materials are stacked on a die and pressed with a compression tool called a punch to promote plastic deformation of the joining interface of the terminal materials. Are joining.

  In the conventional pressure contact of the battery terminal material, when the pressure is applied by the punch, the periphery of the pressurizing portion of the terminal material may be warped and a gap may be formed at the joint interface. In order to prevent the occurrence of warping due to the pressurization, a measure is taken in which the periphery of the punch pressurizing portion is forcibly pressed by another restraining jig in advance.

  As a cold welding method using a restraining jig, the joints of the bus bar and terminal fitting are accommodated in the cavities of the upper jig and the lower jig, and a die is inserted into the cavity from the guide hole to press both joints. There is known a technique for joining by deforming them (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2006-26715 (FIGS. 3 and 4)

  However, in the conventional cold welding method, since a method in which the periphery of the punch pressurizing portion is pressed in advance by a restraining jig has been adopted, the frictional resistance between the restraining jig and the terminal material increases, and the overlapped terminals There is a problem that the plastic deformation at the joint interface of the material is hindered and the joint strength is lowered.

  Accordingly, an object of the present invention is to prevent the occurrence of warping of the joined material due to pressurization and promote plastic deformation at the joining interface of the overlapped joined materials to ensure high joining strength. An object of the present invention is to provide an intermediate pressure welding method and a cold pressure welding apparatus.

  In the cold pressure welding method that achieves the above object of the present invention, first, a material to be bonded on a die is pressed and pressed by a convex portion of a punch. Next, after pressing a part of the material to be joined by the convex portion, the shoulder portion of the punch that protrudes from the base portion of the convex portion to the outside in the direction perpendicular to the advancing and retreating direction from the base portion of the convex portion. Is being pressed by.

  In addition, a cold pressure welding apparatus that achieves the above-described object of the present invention includes a die that supports the stacked materials to be bonded, and a punch that moves forward with respect to the materials to be bonded and applies a compressive load. Yes. The punch moves forward toward the die and pushes a part of the material to be joined to plastically deform, and protrudes outward from the base of the convex portion in a direction perpendicular to the forward / backward direction of the punch. And a shoulder for pressing around the portion pressed by the convex portion.

  According to the cold pressure welding method and the cold pressure welding apparatus according to the present invention, after the stacked materials to be joined are pressed and pressed by the convex portion of the punch, the shoulder protruding from the base portion of the convex portion due to the increase in the pressing amount The part presses the periphery of the part pressed by the convex part. Therefore, not only a restraining jig that presses the periphery of the pressurizing part with a punch becomes unnecessary, but also the shoulder part is covered from the start of pressurizing the material to be joined by the convex part of the punch until the pressing amount is increased. Since the bonding material is not pressed down, the shoulder portion does not hinder plastic deformation (flow of the material) at the bonding interface of the materials to be bonded, so that plastic deformation at the bonding interface of the stacked materials to be bonded is promoted. And by pressing down the periphery of the part pressurized by the convex part of the punch with the shoulder part, while preventing the occurrence of warping of the material to be joined, the joining at the interface of the surrounding part is promoted and the joining strength is ensured. It becomes possible.

It is the schematic which shows typically the cold pressure welding apparatus which concerns on Embodiment 1 of this invention. It is the schematic which shows the punch with which the cold pressure welding apparatus of Embodiment 1 was equipped. It is a perspective view which shows the principal part of the punch with which the cold pressure welding apparatus of Embodiment 1 was equipped. (A) And (b) is an enlarged view which shows the principal part of the punch with which the cold pressure welding apparatus of Embodiment 1 was equipped. (A)-(d) is explanatory drawing which shows the procedure of the cold welding method of Embodiment 1. FIG. (A) And (b) is the schematic explaining the cold-welding method which concerns on the proportionality which pressurizes only by the punch of a conventional shape, without using a restraining jig. (A) And (b) is the schematic explaining the cold pressure welding method which concerns on the proportionality which uses together the punch of a conventional shape, and a restraint jig. It is explanatory drawing which shows the intensity | strength test result of the Example of Embodiment 1 and contrast. It is the schematic which shows typically the cold pressure welding apparatus which concerns on Embodiment 2 of this invention. It is an enlarged view which shows the principal part of the punch with which the cold pressure welding apparatus of Embodiment 2 was equipped, and die | dye. It is explanatory drawing which shows the intensity | strength test result of the Example of Embodiment 2 and contrast. It is an enlarged view which shows the principal part of a comparative punch and die | dye. It is sectional drawing which shows the joining interface of the to-be-joined material of the Example of Embodiment 2. FIG. It is sectional drawing which shows the joining interface of the to-be-joined material to be compared.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and are different from the actual ratios.

  FIG. 1 is a schematic view schematically showing a cold pressure welding apparatus according to Embodiment 1 of the present invention, FIG. 2 is a schematic view showing punches provided in the cold pressure welding apparatus according to Embodiment 1, and FIG. The perspective view which shows the principal part of the punch with which the cold pressure welding apparatus of FIG. 4 was shown, (a), (b) of FIG. 4 is an enlarged view which shows the principal part of the punch with which the cold pressure welding apparatus of Embodiment 1 was equipped. is there.

  First, with reference to FIGS. 1-4, the structure of the cold pressure welding apparatus 1 of Embodiment 1 is demonstrated. As shown in FIG. 1, in the cold pressure welding apparatus 1 according to the first embodiment, an upper table 2 and a lower table 3 extending in the horizontal direction are arranged to face each other with an interval in the vertical direction. Between the upper table 2 and the lower table 3, a pair of left and right compression drive devices 4a and 4b such as a hydraulic cylinder and a cam rod are disposed. The upper table 2 moves up and down by the operation of the compression driving devices 4a and 4b.

  On the lower table 3, a die mount 5 is provided. A die 6 for receiving a compressive load from a punch 10 described later is provided on the die mount 5. The die 6 of the first embodiment has a flat plate shape. The bonded materials 7a and 7b are arranged on the die 6 so as to overlap each other.

  In the first embodiment, for example, two battery terminals, more specifically, a terminal material for a laminated battery of an automobile is applied as the materials 7a and 7b. Here, for example, if the upper material 7a is an aluminum plate, the lower material 7b is a copper plate harder than the aluminum plate. However, it goes without saying that the metal plate material that can be joined by the cold pressure welding apparatus 1 of Embodiment 1 is not limited to the battery terminal material. In addition, FIG. 1 illustrates the case where two members to be bonded 7a and 7b are bonded to each other, but the present invention can also be applied to bonding of three or more members to be bonded.

  A punch 10 connected to the upper table 2 is provided immediately above the die 6 so as to hang down from the upper table 2. A compressive load is applied to the punch 10 via the upper table 2 by the lowering operation of the compression driving devices 4a and 4b.

  As shown in FIG. 2, the punch 10 has a convex portion 11 that plastically deforms the materials to be joined 7 a and 7 b and a shoulder portion (shoulder portion) 12 that suppresses warping of the materials to be joined 7 a and 7 b at the lower portion thereof. The punch 10 and the convex portion 11 are integrally formed. Specifically, the shoulder portion 12 of the punch 10 is a flat plate-like member, and a truncated conical convex portion 11 is provided from the center of the lower surface of the shoulder portion 12 so that the head portion faces downward. In order to prevent damage to the materials 7a and 7b to be joined when the punch 10 is pressurized, the corners of the convex portions 11 are chamfered. The shoulder portion 12 of the punch 10 protrudes outward from the base portion of the convex portion 11 in a direction (horizontal direction in the first embodiment) orthogonal to the forward / backward direction (vertical direction) of the convex portion 11. In addition, as shown in FIG. 3, the horizontal cross-sectional shape of the convex part 11 including the convex part front end surface 13 which functions as a pressurizing surface of the punch 10 is, for example, an oval or oval shape.

  Further, the height h from the convex tip surface 13 to the shoulder 12 of the punch 10 is set in a range of 65 to 95% with respect to the sum D of the thicknesses of the materials 7a and 7b laminated on the die 6. It is preferable (see FIG. 5A described later).

  As shown in FIGS. 4 (a) and 4 (b), in order to promote plastic deformation in the direction (the horizontal direction in the first embodiment) in which the materials 7a and 7b to be joined are pressed when the convex portion 11 of the punch 10 is pressed. The shape of the inner corner portion 11a of the convex portion 11 and the shoulder portion 12 is preferably processed into a tapered shape T or a curved shape R.

  Next, with reference to FIG. 5, the cold welding method of Embodiment 1 implemented using the cold welding apparatus 1 provided with the punch 10 of the said structure is demonstrated. (A)-(d) of FIG. 5 is explanatory drawing which shows the procedure of the cold pressure welding method of Embodiment 1. FIG.

  In the initial state of the cold pressure welding device 1, the punch 10 is lifted together with the upper table 2 by the operation of the compression driving devices 4 a and 4 b. At a temperature lower than the recrystallization temperature of the materials to be bonded 7a and 7b (usually normal temperature), first, the materials to be bonded 7a and 7b are placed on the die 6 so as to overlap each other as shown in FIG.

  Next, as shown in FIG. 5B, the compression drive devices 4 a and 4 b are operated to lower the upper table 2 and apply a compressive load to the punch 10. Then, the convex part 11 of the punch 10 starts to bite into the materials 7a and 7b to be joined. However, at the initial stage of pressurization by the punch 10, the upper material 7a is connected to the shoulder 12 of the punch 10 as shown in part A. It hits only a part.

  If the push-in amount of the punch 10 is increased as it is, as shown in FIG. 5 (c), the push-in amount increases and the upper surface of the upper bonded material 7a and the punch 10 The contact area with the shoulder 12 increases.

  Then, as shown in FIG. 5 (d), most of the shoulder portion 12 is in contact with the upper surface of the upper material to be bonded 7a, and indented with the bonding interfaces of the upper and lower materials 7a and 7b being in close contact with each other. Is completed. That is, as shown in the figure, the inner corner portion 11a formed by the convex portion 11 and the shoulder portion 12 of the punch 10 is not in contact with the upper material 7a, in other words, the convex portion 11 and the shoulder portion of the punch 10. 12 in an approximately triangular region surrounded by the upper member to be bonded 7a or a region surrounded by the inner corner portion 11a formed by the convex portion 11 and the shoulder portion 12 of the punch 10 and the upper member to be bonded 7a. The pushing by the punch 10 is completed with the gap G left. In this way, the materials 7a and 7b to be joined are pressed from both end faces in the plate thickness direction by the punch 10 and the die 6, so that the oxide layer or the like at the joining interface is divided by the plastic deformation caused by the pressurization. The new surfaces are metal bonded (diffusion bonded).

  When the pushing of the punch 10 is completed, a load cell (not shown) detects a set load, and the compression driving devices 4a and 4b raise the punch 10 together with the upper table 2, and all the press contact processes are completed.

  As explained above, according to the cold pressure welding method and the cold pressure welding apparatus of the first embodiment, after pressing and pressing a part of the overlapped materials 7a and 7b by the convex portion 11 of the punch 10, As the amount of pressing increases, the shoulder portion 12 at the base of the convex portion 11 presses the periphery of the portion (pressurizing portion) pressed by the convex portion 11.

  That is, since the shoulder portion 12 does not hold down the materials to be joined 7a and 7b from the start of pressurization of the materials to be joined 7a and 7b by the convex portion 11 of the punch 10, the shoulder portion 12 and the materials to be joined are not pressed. The contact range with the material 7a is small. Therefore, since the shoulder portion 12 does not hinder the plastic deformation (material flow) of the bonded interface between the materials to be bonded 7a and 7b, the plastic deformation at the bonded interface between the stacked bonded materials 7a and 7b is promoted, and the bonded interface The joint strength is improved.

  Further, by further pressurizing the periphery of the pressurizing part (joint part dent) generated by the convex part 11 of the punch 10 with the shoulder part 12, the joining at the interface of the peripheral part is promoted, the joint strength is improved, and the variation is increased. Reduction can be achieved. At this time, as described above, the gap G is left in the region surrounded by the inner corner portion 11a formed by the convex portion 11 and the shoulder portion 12 of the punch 10 and the upper material 7a to be joined. Since the indentation by the punch 10 is completed, the plastic flow in the horizontal direction of the material to be joined 7a is allowed even in the process of reaching the indentation completion state, and as a result, the increase in the plastic flow amount can contribute to the further improvement of the joining strength. Become. Further, by completing the pressing by the punch 10 with the gap G left as described above, it is possible to suppress the reduction in the plate thickness due to the pressing of the punch 10, and this also improves the bonding strength. Become.

  Further, as shown in FIG. 4, the fillet portion connecting the convex portion 11 and the shoulder portion 12 of the punch 10 is set to a taper shape T or a curvature shape R. Accordingly, a plurality of materials to be joined that warp due to pressurization of the punch 10 can all be similarly guided in the material extending direction (horizontal direction in the first embodiment), and the plastic deformation of the interface during pressurization can be made uniform. It is possible to increase the range of diffusion bonding by urging in the direction in which the material extends (horizontal direction in the first embodiment), thereby improving the bonding strength and reducing variations.

  Hereinafter, the cold pressure welding method and the cold pressure welding apparatus according to the present invention will be described in more detail with reference to examples and comparisons according to the first embodiment, but the present invention is not limited to this example. .

(Example)
With reference to FIGS. 1 to 3 and FIG. 5 again, examples of the cold pressure welding method and the cold pressure welding apparatus according to the first embodiment will be described. In the present embodiment, using the cold pressure welding apparatus 1 shown in FIGS. 1 and 2, the materials to be joined 7a and 7b were pressure welded by the procedure of the cold pressure welding method shown in FIG.

  As described above, the punch 10 of the cold welding apparatus 1 includes the convex portion 11 that plastically deforms the materials 7a and 7b to be joined, and the shoulder portion 12 that suppresses the warpage of the pressurizing portion around the convex portion 11. It has.

  In this embodiment, two bonded materials 7 a and 7 b are stacked on the die 6. When the sum D of the thicknesses of the two bonded materials 7a and 7b is 1.4 mm, for example, the height h from the convex tip end surface 13 to the shoulder 12 of the punch 10 is 1.1 mm. Set.

  And when cold-welding method of the to-be-joined materials 7a and 7b was implemented according to the procedure shown in FIG. 5 at normal temperature, the generation | occurrence | production of the curvature up around the pressurization part by the convex part 11 of the punch 10 was not observed. (See (d) in FIG. 5).

  Further, since the bonding interface between the materials to be bonded 7a and 7b is in close contact, and no gap is formed between the interfaces, it is possible to perform pressure welding with high bonding strength. In addition, about the joining strength by the cold welding method of a present Example, it compares later with comparison with the following proportionality.

(Comparison)
Next, with reference to FIG. 6 and FIG. 7, a proportional cold welding method will be described.

  6 (a) and 6 (b) are schematic diagrams for explaining a cold-welding method according to the comparative example in which pressure is applied only by a punch having a conventional shape without using a restraining jig, and FIGS. 7 (a) and 7 (b). ) Is a schematic diagram illustrating a cold-welding method according to a comparative example using a conventional punch and a restraining jig in combination.

  As shown in FIG. 6 (a), the conventional punch 20 provided in the cold welding apparatus has only the convex portion 21, and not only the shoulder portion 12 does not exist as in the above embodiment. The gap G as shown in FIG. 5 is not set. When the cold pressure welding is performed by the punch 20 having no shoulder portion 12 as described above, as shown in FIG. 6B, warpage rises around the pressurizing portion due to the convex portion 21 of the punch 20.

  Then, as shown to (a) of FIG. 7, the cold-welding method based on the comparison which used the punch 20 and the restraining jig | tool 30 of the conventional shape together was performed. The restraining jig 30 is a jig for pressing the periphery of the pressurizing portion by the convex portion 21 of the punch 20 having a conventional shape, and is a separate body from the punch 20. Further, the gap G as shown in FIG. 5 is not set. When such a restraining jig 30 is used to forcibly press the periphery of the pressurizing portion, as shown in FIG. 7B, the warping around the pressurizing portion does not occur. Since the frictional resistance increases with the terminal material, plastic deformation at the bonded interface of the overlapped terminal material is hindered, and the bonding strength is reduced.

(Examination of Example and Comparison with Embodiment 1)
Referring to FIG. 8, the joint strength of the cold welding method in comparison with the present embodiment will be compared. FIG. 8 is an explanatory diagram showing the strength test results in comparison with the present embodiment.

  As shown in FIG. 8, in the comparative cold welding method, even if a compressive load is applied until the load applied to the tip of the convex portion 21 of the punch 20 reaches 80% of the yield stress, it is only about 30% of the target strength. I could not meet.

  On the other hand, in the cold welding method of the present embodiment using the punch 10 having the shoulder 12 and setting the gap G, the load applied to the tip of the convex portion 11 of the punch 10 is a compressive load of 70% of the yield stress. Even so, the target strength could be achieved sufficiently. The vertical axis of the graph in FIG. 8 is a value when the bonding strength of the conventional method is set to 1, and the bonding strength by the cold welding method of this example showed a very high strength four times that of the conventional method. .

  As described above, according to the cold welding method of the present embodiment, it is possible to prevent warpage of the materials 7a and 7b to be joined due to pressurization, and to plastically deform the joining interface of the superposed materials 7a and 7b that are overlapped. It was able to promote and ensure high bonding strength.

  As described above, in the first embodiment, after the superimposed materials 7a and 7b are pressed and pressed by the convex portion 11 of the punch 10, the shoulder projecting from the base portion of the convex portion 11 due to the increase in the pressing amount. The part 12 presses the periphery of the part pressed by the convex part 11. Therefore, it is possible to prevent warpage of the materials to be joined 7a and 7b due to pressurization and to prevent the plastic deformation at the joining interface between the materials to be joined 7a and 7b being superposed, and to superimpose the materials to be joined 7a. , 7b can be promoted plastic deformation at the joint interface to ensure high joint strength.

  Since the periphery of the pressurized portion is further pressurized by the shoulder portion 12 of the punch 10, it is possible to promote bonding at the peripheral interface and improve the bonding strength and reduce variations.

  When the inner corner portion 11a of the convex portion 11 and the shoulder portion 12 of the punch 10 is formed in a taper shape or a curvature shape, the plurality of materials to be joined 7a and 7b that are warped by pressurization of the punch 10 are all the same. The material can be guided in the direction in which the material extends, and the plastic deformation at the interface during pressurization is uniformly promoted in the direction in which the material extends, thereby increasing the range of diffusion bonding, improving the bonding strength, and reducing variation. Can be achieved.

  When the materials to be joined are two battery terminals, it is possible to ensure good joining strength of the battery terminals.

  Next, Embodiment 2 of the present invention will be described. In addition, about the member which has a function similar to Embodiment 1, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  FIG. 9 is a schematic view schematically showing a cold pressure welding apparatus according to the second embodiment of the present invention, and FIG. 10 is an enlarged view showing main parts of the punch and die provided in the cold pressure welding apparatus according to the second embodiment. It is.

  The second embodiment is generally different from the first embodiment in that the die 6 of the cold welding apparatus 1 </ b> A has a convex portion 16. The convex part 16 is arrange | positioned so as to oppose the convex part 11 of the punch 10, and is comprised so that the to-be-joined material 7a, 7b may be supported. Therefore, after pressing a part of the materials 7 a and 7 b to be joined by the convex portion 11 of the punch 10 and then pressing the periphery of the pressurized portion by the shoulder portion 12 at the base of the convex portion 11, the convex portion 16 of the die 6. Can promote the plastic deformation of the joining interface of the materials to be joined 7a and 7b by pressurizing the materials to be joined 7a and 7b.

  That is, it has the convex part 16 also in the support side of the to-be-joined materials 7a and 7b, cooperates with the convex part 11 and the shoulder part 12 of the punch 10, and also actively from the support side of the to-be-joined materials 7a and 7b. It is possible to promote the plastic deformation at the bonding interface of the materials to be bonded 7a and 7b by applying pressure, and the plastic deformation at the bonding interface of the materials to be bonded 7a and 7b is outward in a direction perpendicular to the advancing and retreating direction of the punch 10. Further, by dividing more of the oxide film or the like at the bonding interface, the metal bonding range at the bonding interface can be increased, and the bonding strength can be improved.

It should be noted that the height h ₁ from the convex tip surface 13 of the punch 10 to the shoulder 12 and the height from the convex tip surface 17 of the die 6 to the flat plate portion 18 (height of the convex 16) h ₂ Is set so as not to exceed the height h (see FIG. 2) from the convex tip end surface 13 of the punch 10 to the shoulder 12 in the case where the convex part 16 is not provided (Embodiment 1).

  FIG. 11 is an explanatory view showing the strength test results of the embodiment and the comparative example of the second embodiment, FIG. 12 is an enlarged view showing the main part of the comparative punch and die, and FIG. 13 is an implementation of the second embodiment. Sectional drawing which shows the joining interface of the to-be-joined material of an example, FIG. 14 is sectional drawing which shows the joining interface of the to-be-joined material of a comparison.

The sum D of the thicknesses of the materials to be joined 7a and 7b applied in proportion to the example of the second embodiment was set to 1.4 mm, and the compression load was the same. The height h ₁ of the punch 10 and the height h ₂ of the convex portion 16 of the die 6 in the example of Embodiment 2 were set to be 0.9 mm and 0.2 mm, respectively, and were cold-welded (FIG. 13). reference).

As shown in FIG. 12, the contrast is cold-welded using a punch 10 having a shoulder 12 and a flat plate-shaped die 6 (without a convex portion 16) (see FIG. 14). This corresponds to the embodiment of form 1. The height h ₁ of the proportional punch 10 was set to 1.1 mm. That is, the sum of the height h ₁ and the height h _{2 in} the example of the second embodiment does not exceed the height h ₁ in the comparative example.

  As shown in FIG. 11, it was confirmed that the example of the second embodiment was improved by about 70% compared to the joint strength of the proportionality (example of the first embodiment).

  As mentioned above, in Embodiment 2, it has the convex part 16 also in the support side of the to-be-joined materials 7a and 7b, and it pressurizes from the support side of the to-be-joined materials 7a and 7b actively, It is possible to further promote the plastic deformation of the joining interface of the materials to be joined 7a, 7b. In other words, the plastic deformation at the joint interface of the materials 7a and 7b to be joined is guided outward in the direction perpendicular to the forward / backward direction of the punch 10, and more of the oxide film etc. at the joint interface is divided to increase the metal bonding range of the joint interface. Therefore, the bonding strength can be further improved as compared with the first embodiment.

  As mentioned above, although preferred embodiment of this invention was described, this is an illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. The present invention can be implemented in various modes different from the above-described embodiments without departing from the gist thereof.

  For example, the cold pressure welding method and the cold pressure welding apparatus according to the first and second embodiments are widely applied not only to the bonding of terminals of a laminated battery of an automobile but also to the bonding of battery terminals and soft metal plates. obtain. Moreover, in Embodiment 1, although the die | dye which receives the compressive load provided from a punch is formed in flat form, you may form the recessed part corresponding to the convex part of a punch in the upper surface of die | dye. Furthermore, the mechanism for pressurizing the material to be bonded using a punch and a die is not particularly limited as long as it has means capable of vertically pressing the material to be bonded regardless of whether it is automatic or manual. It is also possible to apply a general press machine such as a hydraulic system or a crank system or a vise.

DESCRIPTION OF SYMBOLS 1,1A ... Cold pressure welding apparatus 2 ... Upper table 3 ... Lower table 4a, 4b ... Compression drive device 5 ... Die mounting base 6 ... Die 7a ... Joined material 7b ... Joined material 10 ... Punch 11 ... Protruding part 11a ... Inner corner 12 ... shoulder 13 ... convex tip end surface 16 ... convex portion 17 ... convex tip end surface 18 ... flat plate shaped portion D ... sum of thickness of material to be joined G ... gap portion h, h ₁ ... punch height h ₂ ... Height of convex part in die T ... Tapered shape R ... Curvature shape

Claims (9)

A first step of pressing and pressing the material to be joined on the die by the convex part of the punch;
After pushing a part of the material to be joined by the convex part, the shoulder part of the punch projecting from the base part of the convex part to the outside in the direction perpendicular to the advancing and retreating direction of the punch. A second process that can be pressed by,
A cold welding method characterized by including   2. The cold welding method according to claim 1, wherein in the second step, the periphery of the pressurized portion is further pressurized by a shoulder portion of the punch.   3. The cooling according to claim 1, wherein, in the second step, the second step is finished in a state where an inner corner formed by the convex portion and the shoulder portion of the punch is not in contact with the material to be joined. Inter-pressure welding method.   In the second step, the second step is finished in a state where a gap is left in a region surrounded by an inner corner portion formed by the convex portion and the shoulder portion of the punch and the material to be joined. The cold welding method according to claim 3. In the first step, the material to be joined is supported by a convex portion of the die disposed so as to be opposed to the convex portion of the punch,
The said 2nd process WHEREIN: The said convex part of the said die | dye accelerates | stimulates the plastic deformation of the joining interface of the said to-be-joined material by pressurizing the to-be-joined material. Cold welding method described in one. A die that supports the stacked materials to be joined;
A punch for advancing and applying a compressive load to the material to be joined;
The punch moves forward toward the die and pushes a part of the material to be joined to plastically deform, and protrudes outward from the base of the convex portion in a direction perpendicular to the forward / backward direction of the punch. And a shoulder for pressing the periphery of the portion pressed by the convex portion.   The cold welding apparatus according to claim 6, wherein a fillet portion between the convex portion and the shoulder portion of the punch is formed in a taper shape or a curvature shape. The die has a convex portion that supports the material to be joined,
The cold press welding apparatus according to claim 6 or 7, wherein the convex portion is disposed so as to face the convex portion of the punch.   The cold welding apparatus according to claim 5, wherein the material to be joined is two battery terminals.

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