Welding rod fixing device and welding rod fixing method using the same

Abstract

The present invention relates to a welding rod fixing device and a welding rod fixing method using the same, comprising: a first surface having a first hole formed in the center thereof so that a welding rod can pass therethrough; a second surface having a second hole formed in the center thereof so that the welding rod can pass therethrough and at a position corresponding to the first hole; a third surface connecting the first surface and the second surface; a space portion formed by an outer circumferential surface formed by the third surface, the space portion being hollow from the outer circumferential surface to a center portion where the first hole and the second hole are connected; and a body portion including a fourth surface forming the space portion; and a coupling portion configured to be inserted into the space portion and to press the welding rod passing through the first hole and the second hole.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0170627 filed on November 30, 2023, and all the contents disclosed in the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a welding rod fixing device and a welding rod fixing method using the same, and more particularly, to a welding rod fixing device for vertically fixing a welding rod and a welding rod fixing method using the same.

Background Art

[0003] As the development of technology and demand for mobile devices increase, rechargeable secondary batteries are being used as an energy source for various mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles, hybrid electric vehicles, etc., which are presented as alternatives to existing gasoline vehicles, diesel vehicles, etc. that use fossil fuels.

[0004] Secondary batteries are classified into cylindrical batteries and prismatic batteries in which the electrode assembly is built into a cylindrical or rectangular metal can depending on the shape of the battery case, and pouch-type batteries in which the electrode assembly is built into a pouch-type case made of an aluminum laminate sheet.

[0005] On the other hand, in the case of a cylindrical secondary battery, the negative electrode tab is resistance-welded to the can, and the can serves as a negative electrode terminal. Thus, when the negative electrode tab is resistance-welded to the can, if the welding angle is not correct, a spatter phenomenon in which molten metal fine particles scatter around the welded portion may occur, which may cause a problem of low voltage failure.

[0006] FIG. 1 is a diagram for explaining a state in which a welding rod is fixed to a welding rod fixing device according to the prior art.

[0007] Referring to Figure 1, the conventional welding rod fixing device 20 fixes the welding rod 10 by interposing the welding rod 10 between two blocks 21 and 22 and joining the two blocks 21 and 22.

[0008] However, a step difference is likely to occur on the upper and lower surfaces of the two blocks 21 and 22, so the welding rod 10 and the welding surface of the workpiece are not perpendicular, reducing the contact area, and furthermore, the increased heat generation leads to over-melting and the occurrence of spatter. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2023-0053831 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] To solve the aforementioned problems, the objective is to provide a welding rod fixing device and a welding rod fixing method using the same, which fixes the welding rod so that no step difference occurs between the upper and lower surfaces and the welding surface of the workpiece is perpendicular to the welding rod. [Means for solving the problem]

[0011] As a technical means to achieve the above-mentioned objectives, a welding rod fixing device according to one embodiment of the present invention has a first surface (110) with a first hole (111) formed in the center through which a welding rod (10) can pass, a second surface (120) with a second hole (121) formed in the center through which the welding rod (10) can pass and at a position corresponding to the first hole (111), a third surface (130) connecting the first surface (110) and the second surface (120), and the third surface (130) formed The invention is characterized by comprising: a body portion (100) having an opening in a part of its outer circumferential surface, forming a space (150) that is hollow from the part of the outer circumferential surface to the central part where the first hole (111) and the second hole (121) are connected, and a fourth surface (140) that forms the space (150); and a connecting portion (200) that can be inserted into the space (150) and is configured to press the welding rod (10) passing through the first hole (111) and the second hole (121).

[0012] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the connecting portion (200) is inserted into the space portion (150) and comes into contact with the fourth surface (140), and is configured to press the welding rod (10) together with the fourth surface (140).

[0013] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the body portion (100) is characterized in that a first groove (141) corresponding to a part of the shape of the welding rod (10) is formed on a fourth surface (140) that contacts the connecting portion (200), and a second groove (210) corresponding to a part of the shape of the welding rod (10) is formed on one surface of the connecting portion (200) that contacts the fourth surface (140).

[0014] Furthermore, a welding rod fixing device according to one embodiment of the present invention is characterized in that it further includes a fastening member (300) such that the connecting portion (200) is inserted into the space portion (150) and then connected to the body portion (100).

[0015] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the fourth surface (140) includes a fastening groove (142) formed so that the fastening member (300) can be inserted, and the connecting portion (200) includes a fastening hole (220) formed at a position corresponding to the fastening groove (142) so that the fastening member (300) can be inserted.

[0016] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the fastening member (300) has male screw threads formed on its outer surface and is configured to pass through the fastening groove (142) and the fastening hole (220) simultaneously, the fastening groove (142) and the fastening hole (220) have female screw threads formed on them, and the fastening member (300), the fastening groove (142), and the fastening hole (220) are connected by a screw connection method.

[0017] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the fastening groove (142) is formed on the side of the space (150), and a plurality of fastening grooves (142) are formed on either side of the first groove (141) so as not to interfere with the first groove (141), and the fastening holes (220) are formed so as to cross one and the other surfaces of the joint (200), and a plurality of fastening holes (220) are formed on either side of the second groove (210) so as not to interfere with the second groove (210).

[0018] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the central part of the fourth surface (140) is configured as a curved surface that is recessed toward the third surface (130), and one surface of the connecting part (200) is configured as a curved surface corresponding to the shape of the central part of the fourth surface (140) so as to interlock with the central part of the fourth surface (140).

[0019] Furthermore, in a welding rod fixing device according to one embodiment of the present invention, the other surface of the joint portion (200) is located inside the space portion (150) and is configured as a flat surface.

[0020] Also, in the welding rod fixing device according to an embodiment of the present invention, the central portion of the fourth surface (140) is configured as a flat surface, and one surface of the coupling portion (200) is configured as a flat surface corresponding to the shape of the central portion of the fourth surface (140) so as to mesh with the central portion of the fourth surface (140).

[0021] Also, in the welding rod fixing device according to an embodiment of the present invention, the other surface of the coupling portion (200) is configured as a curved surface that bulges outward.

[0022] Also, a method for fixing a welding rod using the welding rod fixing device according to an embodiment of the present invention, comprising: (S1) inserting the welding rod (10) so as to pass through the first hole (111) and the second hole (121) simultaneously; (S2) inserting the coupling portion (200) into the space portion (150); and (S3) inserting and fixing the fastening member (300) with respect to the fastening groove (142) and the fastening hole (220).

[0023] Also, in the welding rod fixing method according to an embodiment of the present invention, in step (S2),

[0024] the coupling portion (200) presses a part of the welding rod (10) disposed in the first groove (141) through the second groove (210).

Advantages of the Invention

[0025] As described above, according to the welding rod fixing device and the welding rod fixing method using the same according to the present invention, the first hole and the second hole are respectively formed so that the welding rod can pass through the first surface and the second surface of the integral body portion, and the coupling portion is inserted and fixed to the body portion, so that the welding rod can be maintained in a vertical state.

[0026] Moreover, according to the welding rod fixing device and the welding rod fixing method using the same according to the present invention, while the body part has a first groove so that a part of the welding rod can be accommodated, the coupling part also has a second groove for accommodating a part of the welding rod. Therefore, the welding rod always maintains a vertical state without being distorted, and welding defects can be minimized.

Brief Description of the Drawings

[0027] [Figure 1] It is a diagram for explaining a state in which a welding rod is fixed to a welding rod fixing device according to the prior art.

[0028] [Figure 2] It is a perspective view for explaining a state in which a welding rod is fixed to a welding rod fixing device according to the first embodiment of the present invention.

[0029] [Figure 3] It is a cross-sectional view obtained by cutting the welding rod fixing device shown in FIG. 2 along the XZ plane.

[0030] [Figure 4] It is a cross-sectional view obtained by cutting the welding rod fixing device shown in FIG. 2 along the XY plane.

[0031] [Figure 5] It is a perspective view for explaining the body part of the welding rod fixing device according to the first embodiment of the present invention.

[0032] [Figure 6] It is a perspective view for explaining the coupling part of the welding rod fixing device according to the first embodiment of the present invention.

[0033] [Figure 7] It is a perspective view for explaining a state in which a welding rod is fixed to a welding rod fixing device according to the second embodiment of the present invention.

[0034] [Figure 8] It is a cross-sectional view obtained by cutting the welding rod fixing device shown in FIG. 7 along the XZ plane.

[0035] [Figure 9] Figure 7 is a cross-sectional view of the welding rod fixing device shown, cut along the XY plane.

[0036] [Figure 10] This is a perspective view illustrating the body portion of a welding rod fixing device according to a second embodiment of the present invention.

[0037] [Figure 11] This is a perspective view illustrating the coupling portion of a welding rod fixing device according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0038] Hereinafter, with reference to the attached drawings, embodiments that allow a person with ordinary skill in the art to carry out the present invention will be described in detail. However, in describing in detail the operating principles of preferred embodiments of the present invention, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0039] Furthermore, the same reference numerals shall be used throughout the drawings for parts that have similar functions and operations. Throughout the specification, when it is said that one part is connected to another part, this includes not only direct connections but also indirect connections through other elements in between. Also, when it is said that a component is included, unless otherwise stated, it does not mean that other components are excluded, but rather that other components may be included.

[0040] The welding rod fixing device according to the present invention will be described below.

[0041] Figure 2 is a perspective view illustrating the state in which a welding rod is fixed to the welding rod fixing device according to the first embodiment of the present invention, Figure 3 is a cross-sectional view of the welding rod fixing device shown in Figure 2, cut along the xz plane, and Figure 4 is a cross-sectional view of the welding rod fixing device shown in Figure 2, cut along the xy plane. Furthermore, Figure 5 is a perspective view illustrating the body portion of the welding rod fixing device according to the first embodiment of the present invention, and Figure 6 is a perspective view illustrating the coupling portion of the welding rod fixing device according to the first embodiment of the present invention.

[0042] Referring to Figures 2 to 6, the welding rod fixing device according to the first embodiment of the present invention includes a body portion 100, a connecting portion 200, and a fastening member 300.

[0043] The fuselage portion 100 is composed of a first surface 110, a second surface 120, a third surface 130, a fourth surface 140, and a space portion 150. For example, the fuselage portion 100 may be in the form of a cylindrical block, with a part of the outer surface being open to form the space portion 150.

[0044] However, the body portion 100 is not limited to this, and can be configured to have a hexahedral shape with a portion of the outer surface open to form a space 150. For example, the body portion 100 can be composed of a member having a first surface 110, a second surface 120, and an outer surface, in addition to the space 150.

[0045] More specifically, the first surface 110 is the upper surface of the fuselage 100 (12 o'clock direction, relative to Figure 2), the second surface 120 is the lower surface of the fuselage 100 (6 o'clock direction, relative to Figure 2), and the third surface 130 may be the outer circumferential surface of the fuselage 100. Furthermore, the fourth surface 140 may be a surface formed by an opening in a part of the outer circumferential surface formed by the third surface 130.

[0046] A first hole 111 may be formed in the center of the first surface 110 of the body portion 100, allowing the welding rod 10 to pass through. A second hole 121 may also be formed in the center of the second surface 120, at a position corresponding to the first hole 111, allowing the welding rod 10 to pass through.

[0047] Here, the statement that the second hole 121 is formed in the position corresponding to the first hole 111 means that, with reference to Figure 2, the second hole 121 is formed on the same Z-axis as the first hole 111.

[0048] Furthermore, for example, the first hole 111 and the second hole 121 are preferably set to correspond to the size of the cross-section of the welding rod 10, or to be larger than the size of the cross-section of the welding rod 10, taking into account construction errors, manufacturing errors, etc., so that the welding rod 10 can pass through. In other words, the first hole 111 and the second hole 121 can be formed to a size that allows the welding rod 10 to be inserted without interference.

[0049] The third surface 130 is an outer surface connecting the first surface 110 and the second surface 120, and the space 150 can be formed such that a part of the outer surface formed by the third surface 130 is open, and the space is hollow from the part of the outer surface to the central part where the first hole 111 and the second hole 121 are connected.

[0050] The fourth surface 140 is a surface that forms the space 150, and can be formed by connecting from an open part of the outer peripheral surface formed by the third surface 130 to the central part where the first hole 111 and the second hole 121 are connected. Thus, the space 150 can be formed by the first surface 110, the second surface 120, and the fourth surface 140.

[0051] A first groove 141 may be formed in the body portion 100 that corresponds to the shape of a part of the welding rod 10 relative to the fourth surface 140. For example, the first groove 141 may be formed so as to accommodate (seat) a part of the welding rod 10 that has passed through the first hole 111 and the second hole 121, that is, a part of the welding rod 10 located between the first hole 111 and the second hole 121.

[0052] Furthermore, the fourth surface 140 may be configured to have a curved surface on which the surface where the first groove 141, connecting the first hole 111 and the second hole 121, is formed is recessed toward the third surface 130. Referring to Figure 4, the central part of the fourth surface 140 where the first groove 141 is formed may have a curved surface recessed toward the third surface 130, forming a substantially U-shape.

[0053] Furthermore, referring to Figures 2 to 6, the connecting portion 200 can be inserted into the space 150 of the body portion 100 and may be configured to press against the welding rod 10 passing through the first hole 111 and the second hole 121.

[0054] The connecting portion 200 may be configured to have a shape corresponding to the shape of the space 150 so that it can be inserted into the space 150. In other words, the connecting portion 200 may be configured to have the same shape as the space 150 formed by the fourth surface 140.

[0055] The connecting portion 200 is preferably set to be smaller than the cross-sectional size of the space 150, or to be compatible with the size of the cross-section of the space 150, or to take into account construction errors, manufacturing errors, etc., so that it can be inserted into the space 150. In other words, the connecting portion 200 can be formed to a size that allows it to be inserted into the space 150 without interfering with the body portion 100.

[0056] The joint portion 200 may be inserted into the space portion 150 and in contact with the fourth surface 140, and may be configured to press the welding rod 10 together with the fourth surface 140. For example, the joint portion 200 may be inserted into the space portion 150, and three of its circumferential surfaces may be in contact with the fourth surface 140.

[0057] Furthermore, a second groove 210 corresponding to a part of the shape of the welding rod 10 may be formed on one surface of the joint 200 that contacts the fourth surface 140. For example, the second groove 210 may be formed to accommodate (seat) a part of the welding rod 10 that has passed through the first hole 111 and the second hole 121, that is, a part of the welding rod 10 located between the first hole 111 and the second hole 121. Such a second groove 210 can press the welding rod 10 together with the first groove 110.

[0058] The joint portion 200 may be formed with a curved surface corresponding to the shape of the central part of the fourth surface 140, such that one surface that contacts the central part of the fourth surface 140 (at the 2 o'clock position, relative to Figure 6) interlocks with the central part of the fourth surface 140. In other words, the joint portion 200 may be configured to have a curved surface that bulges outwards on one side.

[0059] Furthermore, the other side of the joint 200 (at the 8 o'clock position, relative to Figure 6) is located inside the space 150 and can be formed as a plane. In other words, referring to Figures 2 and 6, the other side of the joint 200 can be configured as a plane located inside the space 150 such that, after the joint 200 is inserted into the space 150, parts of the first surface 110 and the second surface 120 protrude.

[0060] On the other hand, the fastening member 300 may be configured to connect with the body portion 100 after the connecting portion 200 is inserted into the space portion 150. In other words, the connection between the body portion 100 and the connecting portion 200 can be made by the fastening member 300.

[0061] More specifically, a fastening groove 142 may be formed on the fourth surface 140 of the body portion 100 so that a fastening member 300 can be inserted. The fastening groove 142 is formed on the side of the space portion 150, and multiple fastening grooves 142 may be formed on either side of the first groove 141 so as not to interfere with the first groove 141. For example, two fastening grooves 142 may be formed on either side of the first groove 141, but as another example, four fastening grooves 142 may be formed on either side of the first groove 141.

[0062] Furthermore, fastening holes 220 may be formed in the joint portion 200 so that fastening members 300 can be inserted at positions corresponding to the fastening grooves 142. The fastening holes 220 are formed to cross one and the other surfaces of the joint portion 200, and multiple fastening holes may be formed on either side of the second groove 210 so as not to interfere with the second groove 210. For example, two fastening holes 220 may be formed on either side of the second groove 210, but as another example, four fastening holes may be formed on either side of the second groove 210.

[0063] It is preferable that the fastening grooves 142 and fastening holes 220 are formed so as to be located on the same line (in other words, the X-axis with reference to Figure 2) and in the same number.

[0064] Furthermore, female threads are formed in the fastening groove 142 and fastening hole 220, and male threads are formed on the outer surface of the fastening member 300, allowing them to be connected to each other. For example, the fastening member 300 may be made of a screw member with male threads formed on its outer surface.

[0065] The fastening member 300 passes through the fastening hole 220 and the fastening groove 142 simultaneously and can be connected to the fastening hole 220 and the fastening groove 142 by a screw connection method.

[0066] Therefore, the fastening member 300 can be fixed so that the connecting portion 200 and the body portion 100 are connected to each other.

[0067] Figure 7 is a perspective view illustrating the state in which a welding rod is fixed to the welding rod fixing device according to the second embodiment, Figure 8 is a cross-sectional view of the welding rod fixing device shown in Figure 7, cut along the XZ plane, and Figure 9 is a cross-sectional view of the welding rod fixing device shown in Figure 7, cut along the XY plane. Furthermore, Figure 10 is a perspective view illustrating the body portion of the welding rod fixing device according to the second embodiment, and Figure 11 is a perspective view illustrating the coupling portion of the welding rod fixing device according to the second embodiment.

[0068] Referring to Figures 7 to 11, the welding rod fixing device according to the second embodiment of the present invention is the same as the welding rod fixing device according to the first embodiment described above, with the exception of some components. Therefore, the following description will focus on the differences in components.

[0069] The fourth surface 140 of the body portion 100 constituting the welding rod fixing device according to the second embodiment may be formed with a central portion as a flat surface and a portion of the side surface forming the space portion 150 being cut off. Referring to Figure 9, the fourth surface 140 may be configured to form a rectangle with approximately one side open.

[0070] Furthermore, one surface of the joint 200 that contacts the central part of the fourth surface 140 may be configured as a plane corresponding to the shape of the central part of the fourth surface 140 so as to interlock with the central part of the fourth surface 140.

[0071] Furthermore, the other surface of the joint 200 may be configured as a curved surface that bulges outward. In other words, referring to Figures 7 and 11, the other surface of the joint 200 may be configured as a curved surface having a curvature corresponding to a part of the first surface 110 and the second surface 120.

[0072] Furthermore, the connecting portion 200 can be inserted into the space portion 150, and the other surface of the connecting portion 200 may be located at the same or adjacent point in the perpendicular direction to the edges of the first surface 110 and the second surface 120.

[0073] Here, the front of both sides of the fourth surface 140 corresponds to the open space 150, so a portion of both sides of the connecting portion 200 is exposed. Therefore, when connecting the connecting portion 200 to or separating it from the body portion 100, the exposed portions of both sides can serve as handles that can be grasped by the worker.

[0074] Next, a method for fixing a welding rod using the welding rod fixing device according to the first embodiment of the present invention will be described with reference to Figures 2 to 6.

[0075] The welding rod fixing method according to the present invention includes the steps of (S1) inserting the welding rod 10 so as to pass through the first hole 111 and the second hole 121 simultaneously, (S2) inserting the connecting portion 200 into the space portion 150, and (S3) inserting and fixing the fastening member 300 into the fastening groove 142 and the fastening hole 220.

[0076] In stage (S2), the joint 200 can press a portion of the welding rod 10 positioned in the first groove 141 through the second groove 210.

[0077] As described above, the welding rod fixing device and welding rod fixing method using the first embodiment of the present invention can fix the welding rod 10 by inserting the connecting portion 200 into the space portion 150 and pressing the welding rod 10 while the welding rod 10 has passed through the first hole 111 and the second hole 121.

[0078] Here, the welding rod fixing device according to the first embodiment was described as an example, but the welding rod fixing device according to the second embodiment can also fix the welding rod in a similar manner.

[0079] Although specific parts of the present invention have been described in detail above, such specific techniques are merely preferred modes of implementation and do not limit the scope of the present invention. It will be obvious to those skilled in the art that various changes and modifications are possible within the scope of the present invention and its technical concept, and it goes without saying that such variations and modifications also fall within the scope of the appended claims. [Explanation of Symbols]

[0080] 10 welding rods

[0081] 100 Torso

[0082] 110 Page 1 111 Hole 1

[0083] 120 Side 2 121 Hole 2

[0084] 130 Page 3

[0085] 140 Page 4

[0086] 141 First groove 142 Fastening groove

[0087] 150 Space

[0088] 200 Joint

[0089] 210 Second groove 220 fastening holes

[0090] 300 Fastening members

Claims

1. A body portion including a first surface having a first hole formed in the center through which a welding rod can pass, a second surface having a second hole formed in the center at a position corresponding to the first hole through which the welding rod can pass, a third surface connecting the first surface and the second surface, a space formed such that a part of the outer surface formed by the third surface is open and a hollow space is formed from the part of the outer surface to the central part where the first hole and the second hole are connected, and a fourth surface forming the space, A welding rod fixing device comprising a coupling portion that can be inserted into the space and is configured to press the welding rod passing through the first hole and the second hole.

2. The welding rod fixing device according to claim 1, wherein the connecting portion is inserted into the space and in contact with the fourth surface, and together with the fourth surface, presses the welding rod.

3. The body portion has a first groove formed on the fourth surface that contacts the joint portion, which corresponds to the shape of a part of the welding rod. The welding rod fixing device according to claim 2, wherein a second groove corresponding to the shape of a part of the welding rod is formed in the joint portion on one surface that contacts the fourth surface.

4. The welding rod fixing device according to claim 3, further comprising a fastening member to connect with the body portion after the connecting portion has been inserted into the space portion.

5. The fourth surface includes a fastening groove formed to allow the fastening member to be inserted, The welding rod fixing device according to claim 4, wherein the connecting portion includes a fastening hole formed at a position corresponding to the fastening groove into which the fastening member can be inserted.

6. The fastening member has male threads formed on its outer surface and is configured to pass through the fastening groove and the fastening hole simultaneously. The welding rod fixing device according to claim 5, wherein female screw threads are formed in the fastening groove and the fastening hole, and the fastening member, the fastening groove and the fastening hole are connected by a screw connection method.

7. The fastening grooves are formed on the side of the space and are formed in multiple locations on either side of the first groove so as not to interfere with the first groove. The welding rod fixing device according to claim 5, wherein the fastening holes are formed so as to cross one surface and the other surface of the joint portion, and a plurality of fastening holes are formed on either side of the second groove so as not to interfere with the second groove.

8. The central part of the fourth surface is configured as a curved surface that is concave towards the third surface. The welding rod fixing device according to claim 3, wherein one surface of the joint is configured as a curved surface corresponding to the shape of the central part of the fourth surface so as to interlock with the central part of the fourth surface.

9. The welding rod fixing device according to claim 8, wherein the other surface of the joint is located inside the space and is configured as a flat surface.

10. The central part of the fourth surface is configured as a plane, The welding rod fixing device according to claim 3, wherein one surface of the joint is configured as a plane corresponding to the shape of the central part of the fourth surface so as to interlock with the central part of the fourth surface.

11. The welding rod fixing device according to claim 10, wherein the other surface of the joint is configured as a curved surface that bulges outward.

12. A method for fixing a welding rod using a welding rod fixing device according to any one of claims 1 to 11, (S1) The step of inserting the welding rod so as to pass through the first hole and the second hole at the same time, (S2) The step of inserting the coupling part into the space, A welding rod fixing method comprising the step of (S3) inserting a fastening member into a fastening groove formed on the fourth surface and a fastening hole formed at a position corresponding to the fastening groove of the joint and fixing it.

13. The welding rod fixing method according to claim 12, wherein in step (S2), the connecting portion presses a portion of the welding rod, which is positioned in a first groove corresponding to the shape of a portion of the welding rod, against a fourth surface formed on the body and in contact with the connecting portion, via a second groove formed on the connecting portion and in contact with the fourth surface and in contact with the fourth surface, with respect to a second groove corresponding to the shape of a portion of the welding rod.

Images