JP6367580B2 - Seam welding method - Google Patents

Description

The present invention, by and sandwiched under pressure and energizes the superimposing unit that superimposes the ends of the workpiece roller electrodes relates to the seam welding how to weld the workpieces together while reducing the thickness of the overlapped portion.

  For example, mash seam welding is known as one of the methods for resistance-welding the ends of a first workpiece and a second workpiece made of a metal plate. In the mash seam welding, first, the overlapping portions are formed by overlapping the end portions of the first workpiece and the second workpiece. Then, in a state where the overlapping portion is sandwiched between a pair of rotating roller electrodes, the overlapping portion is relatively moved along the welding direction, so that a pressing force and a welding current are continuously applied to the overlapping portion.

  As a result, resistance heat is generated between the first workpiece and the second workpiece due to mutual contact resistance and the like, so that a melted and solidified portion (nugget) can be formed and the softened overlapped portion is subjected to the above-mentioned applied pressure. Can be crushed. That is, it is possible to obtain a joined body by continuously welding the end portions of the first workpiece and the second workpiece while reducing the thickness of the overlapping portion.

  As above-mentioned, since this superimposition part is crushed by mash seam welding, as for this joined body, the thickness of the junction part of the 1st work and the 2nd work is compared with the thickness of the superposition part before welding. Reduced. However, the thickness of the joint cannot be reduced to a thickness equivalent to each of the first workpiece and the second workpiece. For this reason, a level | step difference arises in the junction part where thickness becomes large compared with the other part of a conjugate | zygote. When this level difference becomes large, there is a concern that sufficient bonding strength cannot be obtained due to stress concentration at the bonding portion.

  Accordingly, a seam welding method shown in Patent Document 1 has been proposed in order to obtain a joined body in which the level difference of the joint portion is reduced. In this seam welding method, the axis of the pair of roller electrodes is inclined in directions opposite to each other with respect to the welding direction (welding line) of the overlapping portion. Thereby, during pressurization and energization by the roller electrode, plastic flow in the direction along the weld line and in the direction perpendicular to the weld line is generated in the overlapped portion, thereby reducing the level difference of the joint portion.

Japanese Patent No. 4500883

  In the above seam welding method, the overlapping portions are formed by overlapping the end portions of the plate-like first workpiece and the second workpiece. That is, in this superimposition part, the area (applied area) of the part to which a pressurizing force is applied in contact with the roller electrode, and the contact area (acting area) of the first work and the second work that are the parts to apply the pressurizing force Are approximately the same size. As described above, when the ratio of the acting area to the applied area is large, the pressing force is effectively applied to the contact surfaces of the first workpiece and the second workpiece from the roller electrode, and the contact surface is well adapted. It becomes difficult to produce.

  Moreover, when the volume of the edge part of the 1st workpiece | work and 2nd workpiece | work which forms a superimposition part becomes large because the working area is large as above-mentioned, the softened 1st workpiece | work and 2nd workpiece | work are plastically flowed and a level | step difference is reduced. When doing so, a high pressure is required. From the above, even in the seam welding method described above, it is difficult to easily and sufficiently reduce the level difference at the joint.

The present invention has been made in order to solve the above problems, it aims to provide a seam welding how that can reduce a step produced at the junction of the first workpiece and second workpiece easily and sufficiently And

In order to achieve the above object, the present invention is configured such that the overlapping portion in which the end portions of the first workpiece and the second workpiece are overlapped with each other is sandwiched between a pair of roller electrodes to pressurize and energize the overlapping portion. A seam welding method for welding the first workpiece and the second workpiece while reducing the thickness of the workpiece,
Forming a notch in the end of at least one of the first work and the second work, and making the end face of the end a notch surface;
The overlapping portions are formed by overlapping the end portions of the first workpiece and the second workpiece so that one surfaces of the respective non-cut surfaces are in contact with each other, and the other surface being the non-cut surface is the above-mentioned Sandwiching the overlapping portion with the roller electrode so as to come into contact with each roller electrode;
Applying pressure and energization to the overlapping portion sandwiched between the roller electrodes;
Have
The notch is formed on the other surface side so that a contact area between the one surface is smaller than a contact area between the roller electrode and the other surface of the end portion forming the overlapping portion. The notch amount increases toward the one surface side.

  In the seam welding method according to the present invention, the contact area between the one surface is smaller than the contact area between the other surface of each of the first workpiece and the second workpiece and the roller electrode in the overlapping portion. In other words, the contact area (action) between the first workpiece and the second workpiece, which is a portion that applies pressure, compared to the area (applied area) where the pressure is applied by contacting the roller electrode of the overlapping portion. (Area) is small. That is, since the ratio of the acting area to the applied area can be reduced, the pressing force from the roller electrode can be concentrated on the contact surface between the first workpiece and the second workpiece. Further, as described above, the contact surface between the first workpiece and the second workpiece is easy to adjust because the working area is small.

  Furthermore, since the cutout is formed at at least one end of the first workpiece and the second workpiece, the volume of the overlapping portion can be reduced. That is, it is possible to reduce the volume of the overlapping portion that needs to be plastically flowed in order to reduce the level difference of the joint portion. As a result, the region in which the first workpiece and the second workpiece can cause a meat flow by plastic flow is expanded, and plastic flow can be easily generated. Thereby, it is possible to reduce the pressurizing force necessary to reduce the level difference of the joint portion.

  Therefore, in this seam welding method, it is possible to effectively apply a pressing force from the roller electrode to the contact surfaces of the first work and the second work, and it is possible to easily reduce the thickness of the overlapping portion. For this reason, it is possible to obtain a joined body in which the level difference of the joining portion is easily and sufficiently reduced without increasing the pressure applied from the roller electrode. That is, it is possible to obtain a high-quality joined body that suppresses the concentration of stress on the level difference of the joined portion and exhibits a good joining strength.

  In the seam welding method, it is preferable that the notch is provided so that an inclination angle of the end surface of the end portion with respect to the other surface is 45 ° to 60 °. In this case, a pressing force can be more effectively applied to the contact surface between the first workpiece and the second workpiece, and plastic flow can be favorably generated in the overlapping portion to which the pressing force is applied. Therefore, the level | step difference of a junction part can be reduced easily and fully, and the joining strength of a joined body can be improved.

  In the above seam welding method, it is preferable to form the notch in both the first workpiece and the second workpiece. In this case, the above effects can be obtained more remarkably.

In addition, the present invention provides the first workpiece and the second workpiece by sandwiching a superimposed portion in which the ends of the first workpiece and the second workpiece are overlapped by a pair of roller electrodes and applying pressure and electricity. A joint obtained by seam welding,
The overlapping portion is formed by overlapping the end portions of the first work and the second work so that one of the surfaces contacts each other, and the other surface of the end portion and the roller electrode are It is sandwiched between the roller electrodes and seam welded so as to contact each other,
At least one of the end portions forming the overlapping portion of the first workpiece and the second workpiece has a contact area between the one surface as compared with a contact area between the other surface and the roller electrode. Is formed such that a notch amount increases from the other surface side toward the one surface side.

  The joined portion of the joined body according to the present invention is obtained from the overlapped portion whose volume is reduced by the amount of the cutout formed in at least one end of the first workpiece and the second workpiece. In this overlapping portion, when being sandwiched between the roller electrodes, the contact area between the first workpiece and the second workpiece is smaller than the contact area with the roller electrode. Therefore, a pressing force is effectively applied from the roller electrode to the contact surface between the first workpiece and the second workpiece. At this time, since the overlapping portion has a small volume as described above, the plastic flow easily and satisfactorily. Therefore, in the joined body obtained by the seam welding, the step of the joining portion is sufficiently reduced. The bonding strength can be improved.

  In the present invention, a cutout is formed in at least one end of the first workpiece and the second workpiece of the overlapping portion. As a result, when the overlapping portion is sandwiched between the roller electrodes and pressed and energized, the end portions forming the overlapping portion of the first workpiece and the second workpiece are in contact with each other as compared to the area in contact with the roller electrode. The area becomes smaller. Therefore, it is possible to effectively apply a pressing force to the contact surface between the first workpiece and the second workpiece from the roller electrode. Further, since the volume of the overlapped portion is small by the amount of the notch formed, plastic flow can be easily generated. As a result, it is possible to easily and sufficiently reduce the level difference of the bonded portion without increasing the applied pressure, and it is possible to obtain a bonded body with improved bonding strength.

It is a principal part schematic block diagram which shows the 1st workpiece | work and 2nd workpiece | work clamped by the roller electrode of the seam welding apparatus for implementing the seam welding method which concerns on embodiment of this invention. 2A to 2D are explanatory views for explaining a process of reducing the thickness by applying pressure and energization to the overlapping portion by the seam welding method according to the embodiment of the present invention. FIG. 3A to FIG. 3D are explanatory views for explaining a process of reducing the thickness by applying pressure and energization to the overlapping portion where the end portions of the plate-like first workpiece and the second workpiece are overlapped.

  Hereinafter, preferred embodiments of a seam welding method and a joined body according to the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, in the seam welding method according to the present embodiment, the end portions 10 </ b> A and 12 </ b> A of the first workpiece 10 and the second workpiece 12 made of a metal plate such as a steel plate are welded to each other, for example, a tailored blank material Etc. are obtained.

  Specifically, the overlapping portions 14 are formed by overlapping the end portions 10A and 12A of the first workpiece 10 and the second workpiece 12 so that the one surfaces 10B and 12B are in contact with each other. At this time, notches 20 and 22 are formed in advance in the end portions 10A and 12A of the first workpiece 10 and the second workpiece 12 forming the overlapping portion 14, respectively. Details of the notches 20 and 22 will be described later.

  For example, when the thickness T of each of the first workpiece 10 and the second workpiece 12 is 0.65 mm, the overlap margin X1 of the overlapping portion 14 is approximately 1.3 (= 2.0 × T) mm to It may be 1.6 (≈2.5 × T) mm (see FIG. 2A). The overlap margin X1 here is the end of the other surface 10C (the back surface of one surface 10B) side of the first workpiece 10 and the other surface 12C (the back surface of one surface 12B) side of the second workpiece 12. It is the distance to the edge.

  Next, the overlapping portion 14 is sandwiched between the pair of roller electrodes 16 and 18 so that the other surface 10C of the first workpiece 10 is brought into contact with the roller electrode 16 and the other surface 12C of the second workpiece 12 is set as the roller electrode. 18 is contacted.

  The roller electrodes 16 and 18 are connected to a power supply unit having a welding power supply, a high-frequency power supply, and the like (not shown). By controlling the output of the power supply unit by a control unit (not shown), a welding current can be supplied to the superimposing unit 14 via the roller electrodes 16 and 18. The magnitude of the welding current may be appropriately set according to the material of the first workpiece 10 and the second workpiece 12, the plate thickness T, the overlap margin X1, and the like, and can be, for example, approximately 15 kA to 30 kA. .

  The roller electrodes 16 and 18 are driven so as to press the overlapping portion 14 from both ends in the overlapping direction by a pressing mechanism (not shown). As a result, it is possible to apply pressure to the overlapping portion 14 from the roller electrodes 16 and 18. The magnitude of the applied pressure may be appropriately set according to the material of the first workpiece 10 and the second workpiece 12, the plate thickness T, the overlap margin X1, and the like, and may be approximately 400 kgf to 600 kgf, for example. .

  Furthermore, the roller electrodes 16 and 18 are rotationally driven by a rotation mechanism (not shown). For example, the roller electrodes 16 and 18 are rolled by the rotating mechanism in a state where the first workpiece 10 and the second workpiece 12 are positioned and fixed by a fixing mechanism (not shown). Thereby, it is possible to continuously pressurize and energize the overlapping portion 14 while relatively moving the roller electrodes 16 and 18 in the welding direction indicated by the arrow in FIG. In addition, it is good also as a structure which positions and fixes the roller electrodes 16 and 18 to a predetermined location, and moves the 1st workpiece | work 10 and the 2nd workpiece | work 12 to a welding direction.

  Further, in the above-described fixing mechanism, for example, the fixing may be performed so that the clamp load on one of the first workpiece 10 and the second workpiece 12 is approximately 3 tons. In the above rotation mechanism, for example, by adjusting the relative moving speed of the roller electrodes 16 and 18 with respect to the overlapping portion 14 to be approximately 9.9 m / min, it becomes possible to perform good welding.

  Here, the notches 20 and 22 will be described with reference to FIG. 2A. The explanatory diagram of FIG. 2A shows a state in which the overlapping portion 14 is sandwiched between the roller electrodes 16 and 18. The cutout 20 is formed so that the cutout amount increases from the other surface 10C of the end portion 10A of the first workpiece 10 toward the one surface 10B. The notch 20 is preferably formed so that the inclination angle θ1 of the end surface with respect to the other surface 10C of the end portion 10A of the first workpiece 10 is 45 ° to 60 °. As a result, as will be described later, the roller electrodes 16 and 18 can effectively apply pressure to the contact surfaces of the first workpiece 10 and the second workpiece 12 and can easily cause plastic flow in the overlapping portion 14. It becomes possible.

  By this notch 20, in the end portion 10 </ b> A that forms the overlapping portion 14, one surface 10 </ b> B and one surface of the second workpiece 12 are compared with the contact area (applied area) between the other surface 10 </ b> C and the roller electrode 16. The contact area (working area) with 12B is reduced.

  Similarly to the notch 20, the notch 22 is formed so that the notch amount increases from the other surface 12C of the end portion 12A of the second workpiece 12 toward the one surface 12B. The notch 22 is also preferably formed so that the inclination angle θ2 of the end surface with respect to the other surface 12C of the end portion 12A of the second workpiece 12 is 45 ° to 60 °. Due to the cutouts 22, the working area of the end portion 12 </ b> A that forms the overlapping portion 14 is also smaller than the application area.

  That is, in the overlapping portion 14, the action area for applying pressure is smaller than the application area where pressure is applied by contacting the roller electrodes 16 and 18. In other words, the contact length Y1 between the first surfaces 10B and 12B of the first workpiece 10 and the second workpiece 12 is smaller than the overlap margin X1 of the overlapping portion 14.

  For example, as shown in FIG. 3A, the overlapping portion 3 in which the notches 20 and 22 are not provided and the end portions 1 </ b> A and 2 </ b> A of the plate-like first work 1 and the second work 2 are overlapped by the roller electrodes 16 and 18. When sandwiched, the application area and the action area are approximately equal. That is, the overlap length X2 of the overlapping portion 3 is equal to the contact length Y2 between the first work 1 and the second work 2.

  Compared with the superimposing portion 3 or the like, in the superimposing portion 14 having a smaller ratio of the acting area to the applied area, the pressure applied from the roller electrodes 16 and 18 is concentrated on the contact surface between the first workpiece 10 and the second workpiece 12. Can be applied efficiently. In addition, the contact area between the first workpiece 10 and the second workpiece 12 becomes easier to adapt because the working area is smaller.

  Moreover, in the superimposition part 14, since the notches 20 and 22 are formed, a volume can be made smaller than the superimposition part 3 grade | etc.,. That is, it is possible to reduce the volume of the end portions 10A and 12A to be plastically flowed by pressurization and to sufficiently secure a region where the meat can flow by the plastic flow.

  For this reason, when the overlapping part 14 is pressed and energized by the roller electrodes 16 and 18, as shown in FIGS. 2B and 2C, the end parts 10 </ b> A and 12 </ b> A are favorably plastically deformed, and the overlapping part The thickness of 14 can be easily reduced. This is clear even when compared with FIGS. 3B and 3C, which show a state in which the overlapping portion 3 is pressurized and energized by the roller electrodes 16 and 18.

  FIG. 2D shows the joint portion 24 obtained by applying pressure and energization to the overlapping portion 14 as described above. Since resistance heat is generated between the end portions 10A and 12A due to mutual contact resistance or the like, the nugget 26 is formed, and the overlapping portion 14 is softened and its thickness is reduced, so that the joint portion 24 is reduced. Is obtained. By performing this over the entire overlapping portion 14 along the welding direction, the joined portions can be obtained by continuously welding the end portions 10A and 12A of the first workpiece 10 and the second workpiece 12.

  As described above, in this seam welding method, pressure is effectively applied to the contact surfaces of the first workpiece 10 and the second workpiece 12 from the roller electrodes 16 and 18, and the thickness of the overlapping portion 14 is easily reduced. Thus, the joint portion 24 having a thickness L1 can be formed. For this reason, it is possible to obtain a joined body in which the step 28 of the joined portion 24 is easily and sufficiently reduced without increasing the pressure applied from the roller electrodes 16 and 18.

  This is also clear when compared with FIG. 3D showing the joint 4 obtained by applying pressure and energization to the overlapping portion 3. That is, in the superimposing unit 3, since the application area and the action area are substantially the same size, the pressure applied from the roller electrodes 16 and 18 is concentrated on the contact surface between the first work 1 and the second work 2 to improve efficiency. It is difficult to give it. Moreover, the contact surface of the 1st workpiece | work 1 and the 2nd workpiece | work 2 is hard to adjust. Furthermore, since the volume of the end portions 1A and 2A to be plastically flowed by pressurization is large, it is difficult to plastically flow the overlapping portion 3 in order to reduce the step 6 of the joint portion 4.

  Therefore, the thickness L1 of the joint 24 can be easily and sufficiently reduced as compared with the thickness L2 of the joint 4 obtained by pressurizing and energizing the overlapping portion 3. That is, the step 28 of the joint 24 can be easily and sufficiently smaller than the step 6 of the joint 4. Since the joint portion 24 can suppress the concentration of stress on the step 28 due to the small step 28, the seam welding method according to the present embodiment provides a high-quality joint that exhibits good joint strength. Can be obtained.

  In addition, this invention is not specifically limited to above-described embodiment, Of course, a various deformation | transformation is possible in the range which does not deviate from the summary.

  For example, in the above embodiment, the notches 20 and 22 are formed in both the end portions 10A and 12A of the first workpiece 10 and the second workpiece 12, respectively. However, if at least one of the notches 20 and 22 is formed in at least one of the end portions 10A and 12A, the above-described effects can be obtained.

DESCRIPTION OF SYMBOLS 1, 10 ... 1st workpiece | work 2, 12 ... 2nd workpiece 1A, 2A, 10A, 12A ... End part 3, 14 ... Overlapping part 4, 24 ... Joint part 6, 28 ... Level difference 10B, 12B ... One surface 10C, 12C ... the other surface 16, 18 ... roller electrode 20, 22 ... notch 26 ... nugget

Claims (3)

The first work and the first work are reduced while the thickness of the superposition part is reduced by sandwiching a superposition part in which the end parts of the first work and the second work are superposed between a pair of roller electrodes and applying pressure and energization. A seam welding method for welding a second workpiece,
Forming a notch in the end of at least one of the first work and the second work, and making the end face of the end a notch surface;
The overlapping portions are formed by overlapping the end portions of the first workpiece and the second workpiece so that one surfaces of the respective non-cut surfaces are in contact with each other, and the other surface being the non-cut surface is the above-mentioned Sandwiching the overlapping portion with the roller electrode so as to come into contact with each roller electrode;
Applying pressure and energization to the overlapping portion sandwiched between the roller electrodes;
Have
The notch is formed on the other surface side so that a contact area between the one surface is smaller than a contact area between the roller electrode and the other surface of the end portion forming the overlapping portion. A seam welding method, wherein a notch amount increases toward the one surface side. The seam welding method according to claim 1, wherein
The seam welding method, wherein the notch is provided so that an inclination angle of an end surface of the end portion with respect to the other surface is 45 ° to 60 °. In the seam welding method according to claim 1 or 2,
A seam welding method, wherein the notch is formed in both the first workpiece and the second workpiece.

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