Methods for creating sculptural objects

Abstract

This invention provides a method for fabricating large-scale additive manufacturing without requiring powder, arc, or laser, and also enabling the creation of dense, thin-walled objects, which was difficult with conventional DEDs. [Solution] The present invention is a method for forming a molded body, comprising the steps of continuously resistance welding a linear member with an electrode for resistance welding, and then continuously resistance welding a linear member to the resist-welded object with the same electrode, and repeating this process to form a laminated body. The present invention also comprises an electrode usable for resistance welding, wherein the electrode is provided with a guide groove capable of receiving a linear member, and the guide groove has at least a straight bottom in its cross-sectional shape, and a resistance welding apparatus equipped with the electrode. The present invention also comprises a resistance welding apparatus comprising a disc-shaped electrode for continuously resistance welding an object, and an insulating guide that cooperates with the disc-shaped electrode and contacts the object during resistance welding.

Description

Technical Field

[0001] The present invention relates to a shaping method of a shaped body. More specifically, it relates to a method, an electrode, and a device for manufacturing a laminated shaped body using resistance welding.

Background Art

[0002] In recent years, various shaping technologies for performing laminated shaping based on 3D model data have been disclosed.

[0003] Among these, Powder bed fusion (PBF) is a method of irradiating a laser onto metal powder to generate a sintered layer, and is currently the most commonly used. This method can perform shaping with high fineness, but due to the nature of spreading powder within a predetermined limited space, it is difficult to apply to large products. Also, a powder removal process that requires delicate handling is necessary, and there are also issues with input efficiency.

[0004] The Material Extrusion (MEX) method is a method of extruding and laminating molten resin from a nozzle to perform shaping. It is excellent in durability, but is not suitable for fine shaping or large-scale shaping, and is considered suitable for prototypes, jigs, and simple types of shaping.

[0005] Directed energy deposition (DED) is a method that applies build-up welding. The base material is heated with a highly directional heat source such as a laser or arc discharge to form a molten pool. A material is introduced into this molten pool and solidified to deposit the material. This method is further classified into a plurality of types mainly according to the combination of the type of heat source and the form of the material.

[0006] The laser + powder method has the highest share among DED, can perform thin-wall shaping, and has high shaping accuracy among DED. However, there are issues with manufacturing costs due to poor material utilization efficiency (much of the input material scatters), issues with powder removal, and spatial limitations for preparing the powder environment.

[0007] The laser-wire method has a high material utilization rate because it uses wire material. However, because it is necessary to melt the wire in the molten pool, the bonding width is limited by the laser beam diameter and wire diameter. For this reason, when creating thin-walled objects, for example, insufficient or excessive heat input can easily lead to manufacturing defects, making manufacturing difficult or requiring delicate heat input control.

[0008] Arc discharge + wire welding is a method that applies common arc welding techniques (MIG welding and TIG welding). Compared to lasers, it has lower equipment costs and higher fabrication efficiency. However, compared to lasers, the heat source distribution of arc discharge is wider, making thin-wall fabrication more difficult than with laser methods.

[0009] Furthermore, since all DED (Directed Earth Printing) methods form a molten pool, the shape accuracy of the printed object is affected by surface tension and gravity. Increasing the printing efficiency results in a larger molten pool, which tends to reduce shape accuracy.

[0010] On the other hand, in space-related technologies, for example, there is a demand for large containers with thin walls (e.g., 2 mm or less). However, there are difficulties in using the above technologies to create such containers, so new fabrication technologies are desired. [Disclosure of the Invention] [Problems that the invention aims to solve]

[0011] Therefore, the present invention aims to provide a new additive manufacturing technology. In particular, it aims to provide an additive manufacturing technology that enables thin-walled fabrication, has good material utilization efficiency, and allows for large-scale fabrication. [Means for solving the problem]

[0012] To solve the above problems, the present invention comprises a method for fabricating a molded body, characterized by repeatedly performing the steps of continuously resistance welding a linear member with an electrode for resistance welding, and then stacking a linear member on top of the resistance-welded object and continuously resistance welding it with the same electrode, thereby fabricating a laminated body.

[0013] Furthermore, it is preferable that the electrode is a resistance welding electrode having a guide groove for receiving a linear member, and that the electrode is a disc-shaped electrode with the guide groove provided along its circumference. It is also preferable that the cross-sectional shape of the guide groove has a straight or curved bottom.

[0014] Furthermore, it is preferable to use a configuration in which the electrode is a disc-shaped electrode and an insulating guide that cooperates with the disc-shaped electrode and restricts the position and / or shape of the linear member during resistance welding. Furthermore, it is preferable that the insulating guide is composed of a roller member, and that the insulating guide is composed of a pair of guide members.

[0015] Furthermore, the present invention relates to an electrode usable for resistance welding, wherein the electrode is provided with a guide groove capable of receiving a linear member, and the guide groove has at least a straight bottom in its cross-sectional shape. It is also preferable that the electrode is a disc-shaped electrode and that the guide groove is provided along its circumference.

[0016] Furthermore, it is preferable that the cross-sectional shape of the guide groove has a pair of straight sides, or that the cross-sectional shape of the guide groove is rectangular with one side open.

[0017] Furthermore, the cross-sectional shape of the guide groove is preferably such that it has one straight side, and the other side relative to the straight side is open.

[0018] Furthermore, it is preferable to include a pair of disc-shaped electrodes that cooperate with the aforementioned electrodes to sandwich the object from both sides.

[0019] The inventors have discovered a new additive manufacturing technology by applying resistance welding (seam welding), a method for continuously joining welded materials. More specifically, they discovered that by continuously resistance welding linear members without gaps, and then continuously resistance welding more linear members onto the welded object, it is possible to create thin-walled structures with good material efficiency and the ability to create large-scale structures.

[0020] Linear members are typically wire members. Various members can be used, such as those with circular, square, rectangular, or other polygonal cross-sections, as long as they are applicable to the present invention. The thickness and diameter are not particularly limited, as long as the linear member can form a molded layer. The length is preferably set based on the length that constitutes each molded layer, which eliminates the removal process or allows for cutting of the non-molded layer components, ensuring high utilization efficiency and easy removal. Furthermore, since no powder is used, there are no spatial limitations. As resistance welding is used, the material is typically assumed to be iron, steel-based metals, or alloys, but it is not limited to other metals or alloys, as long as they are applicable to the present invention.

[0021] Typically, a disc-shaped electrode is used. The disc-shaped electrode is a shape commonly used in seam welding and is suitable for the present invention because it can efficiently perform continuous resistance welding without gaps. However, it is also possible to use a rod-shaped electrode used in spot welding and slide or move it to perform continuous resistance welding without gaps, and the invention is not limited to a disc-shaped electrode as long as it can continuously weld a linear workpiece without gaps. It should be noted that there is a form of seam welding called wire seam welding, but wire seam welding uses a wire as the electrode to prevent electrode wear (see Japanese Patent Publication No. 62-270286, etc.), and is completely different from the present invention in terms of both technical concept and structure.

[0022] In this invention, a laminate is fabricated by repeatedly performing a process of continuously resistance welding linear members, and then continuously resistance welding more linear members to the welded material. Therefore, a laminate with three or more layers can be constructed by this process. Because this invention relies on continuous resistance welding of linear members, unlike lamination using metal powder, there are no yield problems and no need for a residual powder removal process. Furthermore, it does not require a laser or arc, and can be achieved even with thin-wall fabrication of 5 mm or less, 3 mm or less, and especially 2 mm or less, as well as large-scale fabrication. In the examples described later, lamination with a width of 1.2 mm is possible.

[0023] To enable high-precision and effective additive manufacturing, guide grooves may be provided on the electrodes. These guide grooves are provided as a structure for gripping and guiding the position of a linear member, and furthermore, for welding the linear member while shaping it. For example, in the case of a disc-shaped electrode, guide grooves for receiving the linear member are provided along the outer surface. In the case of a rod-shaped electrode, they are provided as part of the tip shape. When the linear member is melted, it is restricted by the walls of the guide groove and can be shaped according to the shape of the guide groove. Furthermore, in order to enable multi-layer additive manufacturing, it is preferable that the welded object has a planar connecting surface.

[0024] Therefore, while it is not excluded that the bottom of the guide groove's cross-section (the deepest part of the groove; which appears as the top edge in the drawings because the workpiece is below) be a curved shape formed by two straight lines forming an acute angle (approximately V-shape) or typically an arc shape (approximately U-shape), it is preferable that the bottom of its cross-section be straight, in other words, that it has a planar deepest part. Furthermore, from the viewpoint of forming the molten linear member, it is preferable that the side walls have a pair of straight side edges in their cross-section. That is, typically the guide groove has a rectangular cross-section with one side open (approximately U-shape), and it is preferable that the side edges constituting the groove are parallel to each other. However, depending on the desired molding shape, they do not have to be parallel to each other, and the angle between the side edge and the bottom (bottom edge) is typically 90 degrees, but it does not have to be 90 degrees depending on the desired molding shape. Furthermore, depending on the desired molding shape, the side edges do not have to be straight. In the case of a rectangle with one side open, the corners may be rounded. In any case, it is desirable that the groove is suitable for the desired shape and lamination. The guide groove enables additive manufacturing even for linear members with curved cross-sections, such as circles. It should be noted that the term "linear" in this application does not mean a strictly and perfectly straight line, but rather encompasses a concept that includes some degree of distortion, deflection, and unevenness in actual implementation.

[0025] Furthermore, assuming the stacking direction is horizontal, it is preferable that the side corresponding to the stacking surface is straight. In addition, to avoid interfering with the previously stacked layers, it is desirable that the guide groove has a side portion on only one side and the other side is open. Therefore, a configuration in which the guide groove has a side portion on only one side can be applied to stacking in directions other than vertical, such as when the stacking direction is horizontal. In other words, the cross-section of the electrode end is configured as a shape obtained by rotating "" 90 degrees to the right, or a left-right inverted shape thereof.

[0026] Furthermore, even in an embodiment without a guide groove, an embodiment can be adopted in which a configuration is used that includes an insulating guide that cooperates with the disk-shaped electrode and restricts the position and / or shape of the linear member during resistance welding. The cross-section formed by the end portion (circumferential portion) of the disk-shaped electrode and the insulating guide constitutes the bottom and side when the guide groove is provided. Typically, the insulating guide is a guide roller made of an insulating material. For example, as an embodiment corresponding to a rectangular guide groove with one side open, in a cross-sectional view, a pair of disk-shaped guide rollers are provided such that their rotation axes are orthogonal to the rotation axis of the disk electrode. If they are laminated in the horizontal direction, an embodiment in which the insulating guide is provided only on one side can be adopted. This configuration is considered to be mainly suitable for curved workpieces and also suitable for processing after the electrode has worn. Since this insulating guide is provided for laminating while forming the linear member, it is provided at least including the position sandwiching the linear member to be welded. Also, the insulating guide only needs to be able to achieve at least the same effect as the guide groove, that is, restrict the position and / or shape of the linear member, and does not mean that it must have a thickness that only sandwiches the linear member. Furthermore, in the case of a linear member having a cross-section (square, rectangular) that is likely to have a planar connection surface, lamination is possible without providing a guide groove or an insulating guide. However, from the viewpoints of gripping the member and maintaining the connection surface shape, especially in the case of a thin-walled shaped object, the guide groove or the insulating guide is useful.

[0027] In the present invention, since the shaping is performed while laminating, there may be cases where it is impossible or inappropriate to sandwich the workpiece from above and below like in so-called general seam welding. Therefore, it is preferable to provide other electrodes as a pair of disk-shaped electrodes that sandwich the object that has already been laminated from both sides. The pair of other disk-shaped electrodes (for the sake of convenience, to distinguish them from the disk-shaped electrodes of the present invention described above, they are referred to as other disk-shaped electrodes) are not the conventional disk-shaped electrodes that sandwich in pairs from above and below, but are arranged to sandwich from both sides while energizing the already laminated part, and the overall configuration uses three disk-shaped electrodes. Therefore, the configuration and technical significance are different from those of the above-mentioned insulating guide. The pair of other disk-shaped electrodes may have the same diameter, but depending on the shape of the laminated shaping, the diameter of the other disk-shaped electrode corresponding to the inside of the thin-walled container may be small, etc., and it is not required to have the same diameter. Also, it is not necessary to provide a guide groove for the other disk-shaped electrodes. Furthermore, it is possible to use this configuration in combination with the above-mentioned insulating guide.

[0028] According to the present invention, similar to general seam welding, it is possible to perform welding in the vertical direction and various other directions (for example, it can also handle three-dimensional curves such as wavy shapes), so it is possible to laminate in a form that is impossible with powder use, and there is also no gravitational influence on the molten pool that occurs in DED. This indicates that it is a new lamination technique and is also advantageous in terms of the utilization of equipment space for the laminated shaping technique. Furthermore, the present invention can also be provided as a resistance welding machine that enables laminated shaping.

Brief Description of the Drawings

[0029] [Figure 1] It is a diagram showing the method of the present invention. [Figure 2] It is a diagram showing the method of the present invention. [Figure 3] It is a diagram showing examples of three guide grooves with different shapes or depths. [Figure 4] It is a diagram showing the cross-sectional shape at the time of the first layer lamination. [Figure 5] It is a diagram showing the result of the second layer lamination experiment. [Figure 6] It is a photograph of a shaped object laminated up to five layers. [Figure 7] This figure shows the joint width at each layered section. [Figure 8] This diagram shows the state with another pair of disc-shaped electrodes installed. [Figure 9] This figure shows an example of another electrode configuration. [Figure 10] This figure shows an embodiment using an insulating guide. [Figure 11] This figure shows another embodiment using an insulating guide. [Modes for carrying out the invention]

[0030] Figures 1 and 2 illustrate the method of the present invention. First, a disc-shaped electrode 1 performs resistance welding on a wire 2, which is a linear member with a circular cross-section, through a base material 3 (for example, cold-rolled steel sheet (SPCC)) while applying pressure. The guide groove 4 of the disc-shaped electrode 1 is provided along the outer circumferential surface of the disc-shaped electrode 1, with the bottom portion 41 of the cross-section being linear, i.e., the deepest part being planar, and the guide groove sides 42 and 43 being provided linearly at a 90-degree angle to the bottom portion. Therefore, the cross-section is rectangular with one side open. As the disc-shaped electrode 1 performs resistance welding on the wire 2 while applying pressure from the situation shown in the left of Figure 1, a nugget 21 is generated and melted as shown in the middle of Figure 1, and shaped to match the shape of the guide groove 4. When the disc-shaped electrode 1 is separated, the molten wire 2 has a planar upper surface (the upper part of the cross-section is linear) as a result of being influenced by the bottom portion 41, and is configured in a shape that is easily stacked on top of it. The sides are also subject to the limitations of the sides 42 and 43, and the shaping is limited to the dotted line in Figure 1. Furthermore, as shown in Figure 2, the resistance welding equipment configuration, including the welding power supply and control device, can be the same as that of a normal seam welding system.

[0031] Figure 3 shows three examples illustrating the shape or depth of the guide groove 4. The left example features a V-shaped guide groove 5 with an entrance (maximum width) of 1.3 mm. The middle and right guide grooves 4 similarly have an end width of 1.3 mm, but all are rectangular in shape with one side open. However, the middle guide groove has a depth of 0.6 mm (hereinafter referred to as shallow guide groove 6), and the right guide groove has a depth of 1.47 mm (hereinafter referred to as deep guide groove 7). Therefore, the shallow guide has a depth less than its width, and the deep guide has a depth greater than its width. Furthermore, as shown in the experiment below, in this embodiment, the depth of the shallow guide groove 6 is smaller than the wire diameter, and the depth of the deep guide groove 7 is larger than the wire diameter. The small circles in Figure 3 indicate the contact point between the electrode and the wire (at the start of welding).

[0032] 1.1 Layer Lamination Experiment First, a first-layer lamination experiment was conducted using V-shaped guide grooves 5 and shallow guide grooves 6. The various settings for electrode shape and current value are shown in Table 1 below.

[0033] [Table 1]

[0034] As shown in the table above, welding experiments were conducted using SE-A50 (Kobe Steel, Ltd.) mild steel wire (1.2 mm diameter) with five different current values ​​ranging from 1.00 kA to 2.00 kA, using V-shaped guide grooves 5 and shallow guide grooves 6. The results are shown in Figure 4. However, the deep guide groove 7 was not used because its depth was greater than the wire diameter and it would come into contact with the base material 3.

[0035] Figure 4 shows the cross-sectional shape when the first layer is laminated. The upper row shows the cross-sectional shape when a V-shaped guide groove 5 is used, and the lower row shows the cross-sectional shape when a shallow guide groove 6 is used. In terms of sufficient bonding with the base material, under the experimental conditions, at 1.00A, the heat input was insufficient and delamination was observed, but the necessary bonding strength could be obtained at 1.25kA or higher. Furthermore, as the current value increases, the contact area with the disc-shaped electrode 1 deforms, and the bonding width also widens.

[0036] Furthermore, there was no significant difference in the joining width with the base material 3 between the V-shaped guide groove 5 and the shallow guide groove 6. This is presumed to be because, despite the difference in the shape of the guide groove 4, the resulting contact area remained almost the same, resulting in no change in resistance and roughly the same amount of heat being generated. On the other hand, regarding the shape of the upper part of the wire (the upper part of the molten wire in each photograph in Figure 4), the V-shaped guide groove 5 retains its rounded shape, while the shallow guide groove 6, which has a straight bottom cross-section, has a more straight cross-section at the top of the wire. Therefore, the molding effect of the guide groove with a straight bottom occurs, and it is considered that the shallow guide groove 6 is more suitable for additive manufacturing.

[0037] 2.2 Layer Lamination Experiment A lamination experiment was conducted on the first layer described above, with the second layer being added. The second layer used shallow guide grooves 6 and deep guide grooves 7, and all other conditions were kept the same, as shown in Table 2 below.

[0038] [Table 2]

[0039] The results are shown in Figure 5. When the first layer was laminated using the V-shaped guide groove 5, delamination occurred regardless of the current value of the first layer, and lamination was not possible (Figure 5, upper right). On the other hand, when the first layer utilized the shallow guide groove 6, delamination occurred in the shallow guide groove 6 for currents of 1.75 kA or higher, which had a sufficient bonding surface, but lamination was possible in the deep guide groove 7 (Figure 5, lower right). Therefore, it can be said that it is preferable to use the deep guide groove 7 for the second layer and beyond. This is thought to be because it is possible to apply a larger heat input while deeply enclosing the wire and fixing its position. Furthermore, it can be said that a larger current setting is preferable for the second layer than for the first layer. However, in conjunction with the experiment for the first layer, it is possible to use the V-shaped guide groove 5 during the final lamination, and the present invention is not limited to the use of the deep guide groove 7, as it is possible to apply a larger heat input with the shallow guide 6.

[0040] 3. Multilayer lamination experiment with 3 or more layers Using the deep guide groove 7, the process of stacking three or more layers was repeated in the same manner as the second layer, resulting in the stacking of four layers. Figure 6 shows photographs of the stacked object from the first to the fourth layer. Figure 7 shows the joint width at each stacked section. The joint width for each layer was 0.9 mm or more (up to 1.3 mm) relative to the 1.3 mm guide width, indicating that sufficient joint width was ensured at all points. Therefore, according to the present invention, it is possible to perform stacking of three or more layers even for linear members with a circular cross-section, providing a new stacking technology. Furthermore, it was demonstrated that stacking is possible even with widths of 2 mm or less, which is difficult with other stacking technologies. In particular, the above example had a width of 1.3 mm, and stacking is possible with any width of 2 mm or less (1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3), not just 5 mm or less or 3 mm or less. Furthermore, these experimental results demonstrate that thin-wall fabrication with a width of 1.3 mm or less (1.2 mm, 1.1 mm, 1.0 mm, and less) is possible by adjusting the wire diameter and guide groove.

[0041] Figure 8 shows a resistance welding apparatus in which a pair of other disc-shaped electrodes 8 and 9 are provided to sandwich the fabricated object from both sides as the layering progresses. In this embodiment, the other disc-shaped electrodes 8 and 9 are provided to sandwich the previously layered material 10 with respect to the disc-shaped electrode 1. This configuration is suitable for preventing a situation where sufficient heat input cannot be obtained due to the distance from the base material 3, for energizing only near the joining interface, and for gripping the previously layered material to maintain its shape. Therefore, like general seam welding, the disc-shaped electrode 1 and the other disc-shaped electrodes 8 and 9 rotate in cooperation. The diameter and thickness of the other disc-shaped electrodes 8 and 9 are the same in the embodiment shown in the drawing, but the embodiment is not particularly limited, and depending on the shape and space of the additive manufacturing, for example, the diameter of the electrode on the inside of a thin-walled container may be reduced. Also, in a cross-sectional view, the rotation axes of the disc-shaped electrode 1 and the other disc-shaped electrodes 8 and 9 are orthogonal, but this embodiment is not limited as long as it is possible to perform additive manufacturing while stably gripping the previously layered material 10. Furthermore, it is not necessary to provide guide grooves for the other disc-shaped electrodes 8 and 9.

[0042] Figure 9 shows an example of an electrode configuration when stacked horizontally. The guide groove 4 has a bottom portion 41 that is straight, while only a side portion 42 is provided on the side, and it is open in the direction opposite to the side portion 42, forming a shape that is a "" rotated 90 degrees to the right. Depending on the stacking direction, a configuration is adopted in which a side portion 41 is provided and the other side is open. With this configuration, wire 2' can be stacked horizontally on a single layer of wire 2 (which has a small diameter because it is already welded). In the example shown in the figure, the depth of the groove is shallower than the wire diameter, similar to the single-layer embodiment described above.

[0043] Figure 10 shows another embodiment of the electrode, in which an insulating guide is used instead of a guide groove. In this configuration, a pair of guide rollers 11 and 12 made of insulating material are provided on both sides of a disc-shaped electrode 1 that does not have a curved guide groove 4, sandwiching the wire 2. They work in cooperation with the disc-shaped electrode 1 to perform a similar role to the sides of the guide groove 4. In cross-sectional view, the rotation axes of the disc-shaped electrode 1 and the guide rollers 11 and 12 are perpendicular. Although only a part of the guide rollers is shown in the drawing, the guide rollers 11 and 12 are cylindrical (tire-shaped) like general rollers. This configuration is mainly suitable for shaping curved sections. Furthermore, in this configuration, as shown in Figure 11, an insulating guide is provided on only one side, and as shown in Figure 9, a shape rotated 90 degrees to the right or its left-right inverted shape can be formed to achieve horizontal stacking. Note that the guide rollers 11 and 12 that serve as insulating guides and the other disc-shaped electrodes 8 and 9 each have different roles and functions and can be used simultaneously. Furthermore, due to the difference in contact area resulting from the side being an insulator, it is expected that a larger current can be used compared to when using the guide groove 4.

[0044] Figure 11 shows a configuration in which an insulating guide is provided on only one side, i.e., only the guide roller 11. This configuration is an example of the configuration when stacked horizontally, as shown in Figure 9. The combination of electrode 1 and guide roller 11 performs the same role as the guide groove 4 shown in Figure 9.

[0045] These experiments demonstrate that the method and electrode configuration of the present invention enable a new type of additive manufacturing. Furthermore, it can be provided as a resistance welding apparatus equipped with these electrodes. Advantages of this resistance welding apparatus include the ability to perform large-scale additive manufacturing without the need for powder, arc, or laser, and simultaneously achieve the creation of dense, thin-walled objects that were difficult to achieve with conventional DEDs. Therefore, it is a new method for materializing objects by stacking layers based on 3D model data, enabling new shapes and offering numerous advantages. [Explanation of symbols]

[0046] 1. Disc-shaped electrode 2, 2' wire 21 Nuggets 3 Base material 4 Guide grooves 41 Bottom 42 Side 43 Side 5 V-shaped guide grooves 6. Shallow guide groove 7 Deep guide groove 8 Other disc-shaped electrodes 9 Other disc-shaped electrodes 10 Already laminated 11 Guide rollers 12 Guide rollers

Claims

1. A linear member is continuously resistance-welded using electrodes for resistance welding. By repeatedly applying resistance welding to the object that has been resistance-welded, by adding a linear member on top and continuously resistance-welding it with the electrode, A method for creating a molded body, characterized by forming a laminated body.

2. The molding method according to claim 1, characterized in that the electrode is a resistance welding electrode having a guide groove for receiving the linear member.

3. The molding method according to claim 2, characterized in that the cross-sectional shape of the guide groove has a straight or curved bottom.

4. The molding method according to claim 2, characterized in that the cross-sectional shape of the guide groove has a straight bottom.

5. The molding method according to claim 4, characterized in that the cross-sectional shape of the guide groove has a pair of straight sides.

6. The molding method according to claim 4, characterized in that the cross-sectional shape of the guide groove has one straight side and the other side is open.

7. The molding method according to any one of claims 1 to 6, characterized in that the electrode is a disc-shaped electrode and the guide groove is provided along the circumference.

8. The electrode is a disc-shaped electrode, The molding method according to claim 1, characterized in that it uses a configuration comprising an insulating guide that cooperates with the disc-shaped electrode and restricts the position and / or shape of the linear member during resistance welding.

9. The molding method according to claim 8, characterized in that the insulating guide is composed of a roller member.

10. The molding method according to claim 8, characterized in that the insulating guides are provided in pairs at positions that sandwich the linear member.

11. An electrode that can be used for resistance welding, The electrode is provided with a guide groove capable of receiving a linear member, The guide groove is an electrode having at least a straight bottom in its cross-sectional shape.

12. The electrode according to claim 11, characterized in that the cross-sectional shape of the guide groove has a pair of straight sides.

13. The electrode according to claim 11, characterized in that the cross-sectional shape of the guide groove is rectangular with one side open.

14. The cross-sectional shape of the guide groove has one straight side, The electrode according to claim 11, characterized in that one side of the linear shape is open to the other side.

15. The electrode according to any one of claims 11 to 14, wherein the electrode is a disc-shaped electrode and the guide groove is provided along its circumference.

16. A resistance welding apparatus comprising the electrode described in any one of claims 11 to 14.

17. A resistance welding apparatus comprising the electrode described in claim 15.

18. The electrode according to claim 15, A resistance welding apparatus comprising a pair of disc-shaped electrodes that cooperate with the electrode described in claim 15 to sandwich an object from both sides.

19. A disc-shaped electrode capable of continuously resistance welding linear members, The system includes an insulating guide that cooperates with the disc-shaped electrode and restricts the position and / or shape of the linear member during resistance welding, Resistance welding equipment

20. The resistance welding apparatus according to claim 19, characterized in that the insulating guide is composed of a roller member.

21. The resistance welding apparatus according to claim 19, characterized in that the insulating guides are provided in pairs at positions that sandwich the linear member.

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