KR102179868B1 - Electrode for bolt welding and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an electrode for bolt welding, which is used to weld a bolt to a metal plate base material as an integrated body through electric resistance welding after leading welding protrusions of the bottom surface of a bolt head to come in close contact with the surface of the base material, while inserting a bolt leg into a bolt hole of the base material. More specifically, the electrode comprises a cylindrical electrode body divided into upper and lower bodies by a setting flange in the center; and an insulator installed by being inserted in a center axis direction of the electrode body. An insertion passage is penetrated in a center axis direction of the insulator such that a leg part of a bolt for welding can be inserted. An insertion hole of a bolt leg is formed through the insulator in the center of the upper surface of the upper body. A screw type fastening part and an installation hole for insulator insertion are formed in an outer circumference part and a bottom part of the lower body, while punching a hole of a predetermined depth on a circumferential part of the installation hole of the lower body to form a protruding support part dented inwards so as to lead the corresponding circumferential part to support the edge of the bottom surface of the insulator, thus quickly and easily forming a stopper structure preventing the insulator from coming out through the installation hole of the lower body, while increasing the reusability of the electrode by enabling the protruding support part to stably and substantially support the insulator, while maintaining a bolt protection function and welding performance of a reused condition at a level which is equal to a non-reused condition.

Description

TECHNICAL FIELD [0001] Electrode for bolt welding and manufacturing method thereof

In order to manufacture a bolt-welded metal plate widely used as a material for automobile parts and various mechanical parts, the present invention inserts the leg of the welding bolt into the bolt hole formed in the metal plate base material, while the bottom of the bolt head of the welding bolt The present invention relates to an electrode for welding bolts and a method of manufacturing the same, in which the corresponding bolt can be welded integrally with the base material by an electric resistance welding method in a state in which the welding protrusion formed on the surface is in close contact with the upper surface of the base material.

In general, the method of manufacturing a bolt-welded metal plate, which is widely used as a material for automobile parts and various mechanical parts, is a bolt hole at a predetermined interval on the base material 3, which is a metal plate, as shown in Figs. After (4) is formed, the base material (3) so that one bolt hole (4) selected from among them corresponds to the insertion path of the insulator (12) for the electrode (10) inserted inside the upper end of the lower electrode (2). After that, the welding bolt (5) is transported to the bolt transfer table (6) so that the leg of the bolt (5) passes through the bolt hole (4) of the base material (3) and the insulator (12) is inserted To be inserted along the line.

In the above state, the upper electrode (1) is lowered to press the bolt head portion, and at the same time, the elevating rod (8) inside the lower electrode (2) is raised so that the upper surface of the electrode body (11) becomes the base material (3). By supporting the bottom surface of the bolt head, the welding protrusion 9 on the bottom surface of the bolt head is strongly in close contact with the upper surface of the base material 3, and then a current is applied to the upper electrode 1 and the lower electrode 2 for welding. As strong electric resistance and high temperature welding heat are induced in the narrow contact area between the protrusion 9 and the base material 3, a method of integrally welding the bolt 5 with the base material 3 is applied.

After the welding operation of the bolt 5 is completed in the above manner, the upper electrode 1 and the elevating rod 8 are restored to their original positions for setting the next welding operation, and the welding protrusion 9 Usually, three or four are protruded on the bottom surface of the bolt head in a certain angular range (90 degrees or 120 degrees), and in the case of bolts 5 for the purpose of watertight function, a ring A welding protrusion 9 in the form of a protrusion is formed, and the electrode body 11 is made of an alloy copper material having very excellent electrical conductivity, and the insulator 12 blocks the high-temperature current generated during the welding operation to prevent the bolt 5 It is made of materials such as ceramic to safely protect the leg of ).

However, in the conventional bolt welding electrode 10 shown in FIGS. 1 and 2, a cylindrical electrode body 11 is manufactured with the bottom surface on which the setting flange 13 is formed is blocked, and the As it has a structure in which the pipe-shaped insulator 12 is inserted and installed along the central axis direction of the electrode body 11, electrodes 10 of various dimensions must be provided according to the leg length of the bolt 5 And, since the setting work of accurately matching the bolt hole 4 of the base material 3 with the insertion passage of the insulator 12 is also dependent on manual work, it caused an unreasonable problem in terms of automation of the welding work.

In order to compensate for the problems of the existing electrode 10 as described above, as shown in FIGS. 3 to 6, the upper body 14 and the lower body 15 are divided by the central setting flange 13. Insertion passage (10a) through which the insulator 12 is inserted and installed along the central axis direction of the electrode body 11, and the leg portion of the welding bolt 5 is inserted along the central axis direction of the insulator 12 By forming through, welding work is possible regardless of the length of the leg of the bolt 5, as well as setting of the base material 3 and the leg of the bolt 5 through the insertion passage 10a of the insulator 12 An electrode 10 has been developed and known to enable automation of welding work by selectively protruding and displacing a guide pin (not shown) that can be mounted.

In other words, the lower body 15 of the electrode body 11 is assembled on the upper side of the lower electrode 2, and then the elevating guide pin provided inside the lower electrode 2 is As it is raised to protrude outward through the insertion passage (10a), the bolt hole (4) of the base material (3) can be accurately set in accordance with the guide pin, while a magnet (electromagnet) provided on the upper surface of the guide pin ( Insulator (12) from the bolt hole (4) of the base material (3) by lowering the guide pin again while attaching the leg of the welding bolt (5) to the upper end of the guide pin using the It can be set so that the bolt leg is inserted over the insertion passage (10a) of.

Through a series of processes as described above, the entire process from setting of the base material 3 and the bolt 5 to the welding of the base material 3 and the bolt 5 can be automatically performed, and for this purpose, the upper body 14 ) In the center of the upper surface of the bolt (5) through the insulator 12, an insertion hole (14a) of the leg portion is formed, and the outer periphery of the lower body (15) is a screw-type fastening part with the lower electrode (2) ( 15a) is formed, and a mounting hole (15b) for inserting the insulator 12 is formed on the bottom surface of the lower body 15, and a guide pin is provided on the bottom surface of the insulator 12 The inclined cutting surface 12a is formed for accurately guiding the insertion passage 10a inside the.

In addition, the insulator 12 is divided into an upper body 17 and a lower body 18 based on the central locking protrusion 19 as shown in FIG. 6, and the upper body of the insulator 12 ( 17) is a sufficient area for the top surface of the electrode body 11 to completely cover the entire welding protrusion 9 of the bolt head (no need for a current supply path to the welding protrusion for quick and accurate induction of electrical resistance) The lower body 18 of the insulator 12 is formed in a thin thickness so as to have an area not to be bypassed, and the lower body 18 of the insulator 12 is the upper body 17 as much as the protruding width of the locking protrusion 19 for safe protection of the bolt leg. ) Is formed thicker in the outward direction.

Therefore, the insertion hole 14a of the upper body 14 constituting the electrode body 11 has the same diameter as the upper body 17 of the insulator 12, and the insulator 12 from the top surface of the electrode body 11 The mounting hole 15b of the lower body 15 forming the electrode body 11 is the same diameter as the lower body 18 of the insulator 12, and the electrode body ( 11) will be formed from the bottom surface of the insulator 12 to the locking protrusion 19, and due to this structure, the insulator 12 inserted into the electrode body 11 through the top-side insertion hole 14a It cannot come out to the outside, but there is a concern that it comes out to the outside through the lower mounting hole (15b).

As described above, the bottom surface of the lower body 15 constituting the electrode body 11 and the insulator can be prevented from coming out of the insulator 12 through the lower mounting hole 15b of the electrode body 11 as described above. A stopper structure is provided between the bottom surfaces of (12), and the stopper structure applied to the conventional bolt welding electrode 10 is as shown in FIGS. 4 and 5(B), the lower body 15 In a state in which the bottom surface of the insulator 12 protrudes from the bottom surface of the insulator 12 by a predetermined thickness, a striking pin or a striking rod having a thin diameter, not shown, is hit at an angle with a hammer or a hammer, and the mounting hole 15b ), the bottom surface of the lower body 15 corresponding to the circumferential portion of the insulator 12 is pushed in about 3 to 4 places toward the edge of the bottom surface of the insulator 12 to form a caulking protrusion 16.

However, in order to apply the caulking protrusion 16 of the above method as a stopper structure of the insulator 12, the electrode body 11 so that the bottom surface of the lower body 15 faces the top, as described briefly above. In the state of being bitten by a jig, etc., butt the bottom surface of the striking pin or striking rod at a specific position on the bottom surface of the lower body 15 corresponding to the circumference of the mounting hole (15b), Not only requires a tricky and cumbersome manual work of strongly hitting it with a hammer or hammer, but also if the insulator 12 is erroneously hit due to a worker's error, the expensive insulator 12 made of ceramic material, etc. There was also a problem that often occurs when the situation is damaged.

In particular, when a defect such as crack or deformation occurs on the top surface of the electrode body 11 in the process of using the electrode 10 for bolt welding, the welding performance of the electrode 10 decreases. The electrode 10 is recycled after removing the defective part by cutting the upper part of the body 11 together with the insulator 12 by a certain amount. A conventional electrode in which the caulking protrusion 16 is applied as a stopper structure. When (10) is to be recycled through milling, each caulking protrusion 16 easily bends downward in the process of cutting the upper side of the electrode body 11 by a predetermined amount using a milling cutter.

More specifically, the electrode body 11 itself is made of an alloy copper material that is very easy to cut, whereas the insulator 12 is made of a hard material that is difficult to cut, such as ceramic, so milling When cutting the upper surface of the electrode body 11 while rotating and lowering the cutter, the insulator 12 is subjected to a strong pressure in the downward direction, and as a result, the insulator as shown by arrows and imaginary lines in FIG. Each caulking protrusion 16, which was simply supporting the bottom surface of (12), is easily bent downward.

As described above, when each caulking protrusion 16 is bent downward, a gap is generated between the inner side of the electrode body 11 and the outer side of the insulator 12, so that the welding performance and the bolt leg Of course, the protective function of the electrode is greatly reduced, and when each caulking protrusion 16 is bent to the bottom of the bottom surface of the electrode body 11, the setting operation of the electrode 10 to the lower electrode 2 is also very difficult. In severe cases, as each caulking protrusion 16 is broken and separated from the electrode body 11, a situation in which the supporting function of the insulator 12 itself cannot be performed may be caused. There is a problem in that enormous time and economic loss such as re-forming the caulking protrusion 16 or replacing the electrode 10 itself is caused.

Korean Patent Registration No. 10-0687485

The present invention has been conceived to solve the conventional problems as described above, and provides a stopper structure that prevents the insulator from coming out from the mounting hole of the lower body between the bottom surface of the lower body forming the electrode body and the bottom surface of the insulator. , A ring that is pushed inward to support the edge of the bottom surface of the insulator by performing punching of a predetermined depth on the circumference of the mounting hole on the bottom surface of the lower body formed protruding from the bottom surface of the insulator by a certain thickness. It is possible to provide the protruding support in the form of a stopper structure, and through this, it is possible to form a stopper structure of the insulator more quickly and easily than in the conventional case, and at the same time, the protruding support as the stopper structure makes the insulator very strong. The electrode for bolt welding and its manufacturing method are designed to maintain the same level of welding performance and bolt leg protection function as before recycling, while increasing the recyclability of the electrode by milling processing by supporting it stably. To provide is the main technical challenge.

In the present invention as a means for solving the above technical problem, an insulator is inserted and installed along a central axis direction of a cylindrical electrode body, and an insertion passage through which a leg portion of a welding bolt is inserted is inserted along the central axis direction of the insulator. The electrode body is formed through, and the electrode body is divided into an upper body and a lower body based on a setting flange protruding along the central outer periphery, and an insertion hole of the bolt leg through an insulator is formed in the center of the upper surface of the upper body. , A screw-type fastening part is formed on the outer periphery of the lower body, and a mounting hole for inserting the insulator is formed on the bottom surface of the lower body, and the bottom surface of the lower body protrudes from the bottom surface of the insulator by a predetermined thickness. In the electrode for bolt welding, the stopper structure is provided between the bottom surface of the lower body and the bottom surface of the insulator so that the insulator does not come out from the mounting hole of the lower body, wherein the stopper structure is constant from the mounting hole of the lower body. A ring-shaped punching groove or at least two radially arc-shaped punching grooves formed on the bottom surface of the lower body along the circumferential direction of the hole with a clearance gap, the circumferential portion of the mounting hole corresponding to the clearance gap is the bottom of the insulator. It is characterized in that it is a protruding support that is pushed inward to support the edge of the surface, and the punching groove forms a cross section that is concave in the form of a "∧" shape from the bottom surface of the lower body, and provides the protruding support. The inner circumferential surface of the groove is characterized in that it is bent roundly in the direction of the central axis of the electrode body.

In addition, the electrode manufacturing method for bolt welding of the present invention for forming the stopper structure, in which a cylindrical electrode body is vertically mounted on a lower mold, and the bottom surface of the lower body faces upward. In the electrode setting step, by lowering the punching rod of the upper mold toward the electrode body set on the lower mold, a punching blade protruding from the bottom surface of the punching rod in the form of "∨" is inserted through the bottom surface of the lower body. The punching blade is formed by protruding circularly along the circumference of the bottom surface of the punching rod, or punching the arc-shaped punching blades radially arranged in a number of at least two or more. It is formed to protrude along the circumference of the bottom surface of the rod, but by providing a predetermined clearance gap between the punching diameter provided by the punching blade and the hole diameter provided by the mounting hole on the bottom of the lower body, It is characterized in that the circumferential portion of the corresponding mounting hole is formed into a protruding support that is pushed inward to support the edge of the bottom surface of the insulator through a punching step, and a clearance gap provided between the punching diameter and the hole diameter Is within the range of 0.5 to 1.5 mm, the protruding thickness of the bottom surface of the lower body based on the bottom surface of the insulator is within the range of 0.8 to 2 mm, and the insertion depth of the punching blade is 1 of the protruding thickness of the bottom surface of the lower body. /2 to 4/5, the inclination angle of the outer surface of the punching blade is in the range of 0 to 10 degrees, while the inclination angle of the inner surface of the punching blade is within the range of 30 to 60 degrees, The bottom surface of the punching rod, corresponding to the inner side of the punching blade, is characterized in that it is a spherical concave portion connected to the sharp tip portion of the bottom of the punching blade.

According to the present invention as described above, the electrode body is mounted on the lower mold so that the bottom surface of the lower body forming the electrode body faces upward, and then the punching rod of the upper mold is lowered to the bottom surface of the punching rod. By applying a press punching method in which a provided ring-shaped punching blade or a plurality of arc-shaped punching blades having a radial arrangement structure is inserted into the bottom surface of the electrode body by a predetermined depth along the periphery of the mounting hole of the lower body. It provides the effect of forming the stopper structure of the insulator very quickly, easily and economically than in the conventional case in which 3 to 4 caulking protrusions were formed by hitting the hitting rod at an angle with a hammer or hammer.

In addition, by providing a protruding support in the form of a stopper in the form of a stopper so that the periphery of the mounting hole of the lower body supports the edge of the bottom surface of the insulator, the insulator is very robust and stable compared to the conventional caulking protrusion. It provides a supportive effect, and in particular, only the upper part of the protruding support is wedge-engaged with the edge of the bottom surface of the insulator, while the rest of the protruding support is rounded in the direction opposite to the direction in which the insulator pushes the corresponding support. It is effective to provide a stopper with an optimal structure that can further maximize the support strength of the insulator by making it bent so that it is curved.

Through this, as defects such as cracks or deformations occur on the upper surface of the electrode body in the process of using the electrode for bolt welding, the upper part of the electrode body is cut off by a certain amount along with the insulator through milling, etc. When removing the part, even if the strong pressing force that pushes the insulator downward by the milling cutter acts, the protruding support can firmly and stably support the corresponding pressing force without any deformation, so the electrode by milling processing Not only can the recyclability of the material be greatly improved, but also the welding performance during the recycling and the protection function of the bolt leg can be maintained at the same level as before the recycling.

1 is a schematic diagram showing a welding method using an electric resistance bolt welding machine.
Figure 2 is a cross-sectional view of the use state of Figure 1;
3 is an external perspective view showing a conventional electrode for bolt welding.
Figure 4 is a bottom perspective view of Figure 3;
5A and 5B are plan and bottom views of FIG. 3.
Figure 6 is a side cross-sectional view of Figure 3;
7 is a bottom perspective view showing an electrode for bolt welding according to an embodiment of the present invention.
Figure 8 is a plan view of Figure 7;
9 is a side cross-sectional view of an electrode for bolt welding according to an embodiment of the present invention.
10 and 11 are schematic diagrams showing a method of manufacturing an electrode for bolt welding according to the present invention.
12 is a bottom perspective view showing an electrode for bolt welding according to another embodiment of the present invention.
13 is a plan view of FIG. 12;
14 and 15 are plan views showing another arrangement structure of punching grooves.

Hereinafter, the present invention for achieving the above object will be described in detail with reference to the accompanying drawings.

In the electrode 10 for bolt welding according to an embodiment of the present invention, an insulator 12 is inserted and installed along the central axis direction of the cylindrical electrode body 11, as shown in FIGS. 7 to 9 , Along the direction of the central axis of the insulator 12, an insertion passage 10a into which the leg portion of the welding bolt 5 is inserted is formed through, and the electrode body 11 protrudes along the central outer periphery. It is divided into an upper body 14 and a lower body 15 based on the setting flange 13.

An insertion hole 14a of the leg portion of the bolt 5 through the insulator 12 is formed in the center of the upper surface of the upper body 14, and the outer periphery of the center side of the upper body 14 is milled as described above. A marker in the shape of a groove is provided to indicate the maginot line of recycling of the electrode 10 by, and a screw-type fastening part 15a with the lower electrode 2 is provided at the outer periphery of the lower body 15 It is formed, and a mounting hole (15b) for inserting the insulator 12 is formed on the bottom surface of the lower body (15).

In addition, the insulator 12 is also divided into an upper body 17 and a lower body 18 based on the central locking protrusion 19, and the upper body 17 of the insulator 12 is an electrode body The upper surface of (11) is formed in a thin thickness to have a sufficient area to completely cover the entire welding protrusion (9) of the bolt head, and the lower body (18) of the insulator (12) is For protection, it is formed thicker outwardly than the upper body 17 by the protruding width of the locking protrusion 19, and the bottom surface of the insulator 12 is inclined upwardly inclined toward the insertion passage 10a. It is formed by the surface 12a.

The basic configuration described above is in line with that mentioned in the prior art, and in some cases, the slope of the bottom surface of the marker and/or insulator 12 of the upper body 14 constituting the electrode body 11 The cutting surface 12a may be omitted, and the insulator 12 may have a simple pipe shape as shown in FIGS. 1 and 2, while a special insulator manufactured by heat treatment of a stainless material instead of a ceramic material ( It should be noted that KCF) and the like may be used, and the constituents constituting the substantial part of the present invention are provided between the bottom surface of the lower body 15 constituting the electrode body 11 and the bottom surface of the insulator 12 It relates to the improvement of the stopper structure.

The stopper structure constituting the main part of the present invention is formed so that the bottom surface of the lower body 15 protrudes from the bottom surface of the insulator 12 by a predetermined protruding thickness t1, as shown more clearly in FIG. 9. In one state, in the ring-shaped punching groove 20 formed on the bottom surface of the lower body 15 along the circumferential direction of the hole with a certain clearance distance d1 from the mounting hole 15b of the lower body 15 Accordingly, the circumferential portion of the mounting hole 15b corresponding to the clearance gap d1 becomes a protruding support portion 21 pushed inward to support the edge of the bottom surface of the insulator 12.

Here, the clearance gap (d1) provided to form the protruding support part 21 means the punching diameter D2 and the lower body of the punching groove 20 by the punching blade of the punching rod to be described later. It refers to the distance provided between the hole diameters D1 provided by the mounting hole 15b of 15). As shown in FIG. 9, the clearance gap d1 is the hole at both ends of the punching diameter D2. Since there is a gap provided between both ends of the diameter (D1), the actual design dimension is d1 = (D2-D1)/2, and the punching diameter (D2) is the uppermost vertex of the punching groove (20). It becomes the length connected in the horizontal direction.

In the case of the electrode 10, which is usually used to manufacture a bolt-welded metal plate by the electric resistance welding method, the dimensions are almost standardized as shown in Table 1 below, so based on the electrode 10 of the corresponding standard. The above marginal interval d1 applied to the present invention and the numerical limit range for the other parts will be described. When the bolt welding electrode 10 is manufactured to be larger or smaller than the standard shown in Table 1, the numerical limit It should be noted at the outset that the range can also be increased or decreased in proportion to this.

Specification of electrode for bolt welding (10) Height of electrode body (11) 24mm Height of insulator (12) 23mm Height of upper body (14) 10mm Height of lower body (15) 9mm Setting flange (13) thickness (height) 5mm Diameter of electrode body 11 (including flange) 25mm Diameter of upper body (14) 18mm Diameter of lower body (15) (including fasteners) 20mm Diameter of insertion passage (10a) 6~6.5mm Diameter of insertion hole 14a 8mm Diameter of mounting hole (15b) 12mm The thickness of the upper body 17 of the insulator 12 0.75~1mm The thickness of the lower body (18) of the insulator (12) 2.75~3mm

In the bolt welding electrode 10 having such a standard, it is preferable that the clearance gap (d1) applied to the present invention is within the range of 0.5 to 1.5mm, because the clearance gap (d1) of less than 0.5mm In, although the convenience of punching can be achieved, the structural strength of the protruding support part 21 formed by punching is slightly lowered, and when the clearance distance d1 exceeds 1.5 mm, the protruding support part 21 The structural strength of) can be sufficiently improved, but a high press pressure is required during punching, and there is a risk of damage to the electrode body 11 or the insulator 12.

In addition, the protruding thickness t1 of the bottom surface of the lower body 15 based on the bottom surface of the insulator 12 is preferably within the range of 0.8 to 2 mm (1 mm according to the standard in Table 1). And, it is preferable that the insertion depth (t2) of the punching blade forming the punching groove 20 is within the range of 1/2 to 4/5 of the protruding thickness (t1) of the bottom surface of the lower body 15, The reason is that the reason for limiting the dimensional range of the clearance gap d1 described above, that is, the convenience of the punching operation and the structural strength of the protruding support part 21 are simultaneously secured.

Even more preferably, as shown in the enlarged portion of FIG. 9, the punching groove 20 forms a concave cross-section from the bottom surface of the lower body 15 in a "∧" shape, while the protrusion The inner circumferential surface (right circumferential surface based on the enlarged portion) of the punching groove 20 providing the support part 21 is bent in a round shape in the direction of the central axis of the electrode body 11. Through this, only the upper end of the protruding support 21 provides a support end 22 that is engaged in a wedge-like manner with the edge of the bottom surface of the insulator 12 and a predetermined protrusion width (d2) (within 0.5 mm). On the other hand, the rest of the protruding support part 21 is bent in a rounded shape in a direction opposite to the direction in which the insulator 12 pushes the corresponding support part, so that the optimum support strength of the insulator 12 can be further maximized. It is to provide a stopper structure.

Hereinafter, a method of manufacturing the electrode for bolt welding of the present invention for forming the stopper structure as described above will be described in detail with reference to FIGS. 10 and 11.

First, the punching mold 23 used in the present invention is preferably a 2 to 3 ton hydraulic or pneumatic press or a manual hand press that can perform punching by placing it on the top of a table, and the corresponding punching The lower mold 27 of the mold 23 is provided with a setting hole 28 through which the electrode body 11 can be erected in the vertical direction, while the upper mold 24 of the punching mold 23 It is preferable to use a punching rod (25) for forming the protruding support (21), and the impact of the punching operation between the upper mold (24) and the punching rod (25) is used. It is preferable to interpose a buffer spring or a buffer cylinder that can be reduced.

In addition, the method of manufacturing an electrode for bolt welding according to the present invention is after all the processes from processing of the electrode body 11 and the insulator 12 to insertion of the insulator 12 through the electrode body 11 , It is best to interpret it as a final productization step of forming a stopper of the insulator 12 on the bottom surface of the electrode body 11 of the electrode 10, and the process is the electrode body 11 and the lower mold 27 The electrode setting step (FIG. 10) in which the bottom surface of the lower body 15 faces the upper direction and the electrode body 11 set on the lower mold 27 faces the upper part. By lowering the punching rod 25 of the mold 24, a punching molding step (Fig. 11) of forming the protruding support portion 21 as a stopper structure is sequentially performed.

In the punching forming step, the punching blade 25a protruding from the bottom surface of the punching rod 25 in the form of "∨" is inserted at a predetermined insertion depth t2 along the bottom surface of the lower body 15 by a predetermined pressing pressure. The punching blade 25a will be formed to protrude in a circular shape along the circumference of the bottom surface of the punching rod 25 for this purpose, and the punching diameter D2 by the punching blade 25a ) And the hole diameter (D1) by the mounting hole (15b) on the bottom of the lower body (15), a predetermined clearance distance (d1) as described above will be provided, and the clearance distance (d1) The circumferential portion of the corresponding mounting hole 15b is formed into a protruding support portion 21 pushed inward to support the edge of the bottom surface of the insulator 12 through a punching molding step.

In the drawing, in the lower mold 27, the upper body 14 constituting the electrode body 11 is inserted along the setting hole 28 at the center thereof, while the setting flange 13 at the center of the electrode body 11 Has a structure that is placed on the upper surface of the punching rod 25, and in the center of the bottom surface of the punching rod 25, inclined cutting of the bottom surface of the insulator 12 from the mounting hole 15b of the lower body 15 constituting the electrode body 11 By being inserted along the insertion passage 10a of the insulator 12 through the surface 12a, a bar-shaped punching guide 26 that substantially guides the punching operation extends downward by a predetermined length. Has been.

Instead of forming the rod-shaped punching guide 26 at the center of the bottom surface of the punching rod 25 as described above, a guide tube guided along the lower body 15 at the outer periphery of the punching rod 25 tube) is also possible, but it is desirable to apply the former method as much as possible because there is a possibility that the fastening portion 15a of the lower body 15 may be damaged by the guide tube, and in the enlarged portion of FIG. As described above, the inclination angle θ provided by the outer surface (the left surface based on the enlarged portion) of the punching blade 25a is in the range of 0 to 10 degrees, while the inner surface of the punching blade 25a (enlarged It is preferable that the angle of inclination provided by the right side) is within the range of 30 to 60 degrees.

As described above, the reason why the outer side inclination angle θ and the inner side inclination angle of the punching blade 25a are differently limited to a range of 0 to 10 degrees and 30 to 60 degrees, respectively, is that the electrode body ( 11) by suppressing the phenomenon that the upper periphery of the lower body 15 is pushed outward to the maximum so that dimensional deformation does not occur in the fastening part 15a of the lower body 15, and at the same time, the punching blade 25a In the case of the protruding support part 21 molded by ), it is the optimum range that allows the insulator 12 to be supported more firmly and stably by being sufficiently pushed in the inner direction of the electrode body 11. to be.

Therefore, the penetration angle of the punching blade 25a (an angle provided by the punching blade body itself) is at least 110{180-(10+60)} degrees to a maximum of 150{180-(0+30)} degrees. The smaller (sharp) the penetration angle of the bar and the punching blade 25a, the faster the punching operation itself can be performed with a low press pressure, but the disadvantage of not sufficiently pushing the protruding support part 21 is caused, and the punching blade As the penetration angle of (25a) is increased (duller), the protruding support portion 21 can be pushed out to a larger width, but disadvantages such as requiring a somewhat high press pressure for the punching operation are caused, so that the punching blade 25a ) It is desirable to selectively apply the appropriate angle range in consideration of the material and press standard.

In the accompanying drawings, the shape of the punching groove 20 and the angle of the punching blade 25a are slightly different from the actual manufacturing dimensions in order to facilitate understanding of the structure of the stopper applied to the present invention, its molding process, and the molding principle. As expressed parts may exist, it is to be understood that the actual interpretation of the present invention should be based on the description of the claims and the detailed description supporting them, not the accompanying drawings. When a predetermined angle of inclination (θ) is given to the outer surface, the lower outer circumferential surface of the punching rod 25 itself is inclined cutting surface 25b than the case of separately forming the punching blade 25a on the bottom surface of the punching rod 25. ) And using it as a punching blade 25a is more economical.

As an additional matter, the bottom portion of the punching rod 25 corresponding to the inner side of the punching blade 25a is formed into a spherical concave portion 25c connected to the sharp tip portion of the lower end of the punching blade 25a. When formed, the inner circumferential surface of the punching groove 20 providing the protruding support portion 21 in the process of passing through the punching forming step is rounded in the direction of the central axis of the electrode body 11 by the groove portion 25c. It can be formed naturally so as to be bent so as to be bent, and the amount of deformation of the protruding support part 21 and the support strength of the insulator 12 accordingly can be adjusted according to the radius of curvature (radius of the curve) applied to the groove part 25c. have.

In other words, as the radius of curvature of the concave groove portion 25c increases, the amount of deformation of the protruding support portion 21 and the support strength of the insulator 12 may be increased, and as the radius of curvature decreases, the protruding support portion 21 ) And the corresponding support strength of the insulator 12 decreases. Contrary to the deformation amount of the protruding support part 21 and the corresponding support strength of the insulator 12, the convenience of work according to press punching is It is inversely proportional to the radius of curvature, and in consideration of all these points, it is preferable that the radius of curvature of the concave groove 25c be about 0.5 to 2 times the diameter of the punching rod 25 based on the diameter of the punching rod 25.

12 and 13 is a bolt welding electrode 10 according to another embodiment of the present invention, in place of the ring-shaped punching groove 20 as in the above-described embodiment, at least two or more ( As the arc-shaped punching grooves 20 are formed in a radial shape, the circumferential portion of the mounting hole 15b in which each arc-shaped punching groove 20 is formed is the bottom surface of the insulator 12 The circumferential portion of the mounting hole (15b) in which the arc-shaped punching groove (20) is not formed is made to be a protruding support part (21) pushed inward to support the edge, and other than that The rest of the configuration is made in the same manner as in the previously described embodiment.

In other words, in the case of the electrode 10 for bolt welding according to another embodiment of the present invention, the protruding support part 21 is an internal gear from the inner peripheral surface of the mounting hole 15b according to the arrangement of the arc-shaped punching groove 20 It is formed to protrude in a shape, and as shown in Figs. 14 and 15, the arc-shaped punching groove 20 is formed in two and eight pieces along the circumferential direction of the mounting hole 15b, respectively, the arc-shaped punching groove 20 The number of the arc-shaped punching grooves 20 may be formed from at least two to as many as dozens, but the number of arc-shaped punching grooves 20 is preferably about 2 to 8 in consideration of the manufacturing side of the punching rod 25 described above. .

As described above, the number of arc-shaped punching grooves 20 is about 2 to 8, but the supporting force of the protruding support portion 21 by each arc-shaped punching groove 20 is protruded by the ring-shaped punching grooves 20 Each arc-shaped based on the total circumferential length (2πr) of the circumferential portion of the mounting hole (15b) corresponding to the position where the arc-shaped punching groove (20) is formed so that the supporting force of the support portion (21) It is preferable that the sum of the lengths of the arcs provided by the punching grooves 20 (length) be at least 50% (2πr×0.5) to 95% (2πr×0.95) of the circumferential length. .

In accordance with this point of view, Figs. 13 and 15 show an application example in which the arc length provided by each arc-shaped punching groove 20 is formed longer than the arc length corresponding to the arrangement interval, and in Fig. 14, two arcs close to a semicircle An application example in which the punching grooves 20 are formed to face each other with a relatively short arrangement interval is shown, the number and dimensions (length) and arrangement intervals of the arc-shaped punching grooves 20 shown in FIGS. 13 to 15 are also the present invention. As only one representative example that can be applied to, it is revealed that the number and dimensions (length) of the arc-shaped punching grooves 20 and the arrangement interval thereof can be variously adjusted.

In addition, the manufacturing method of the electrode 10 for bolt welding according to another exemplary embodiment of the present invention also undergoes the same process as the manufacturing method of the exemplary embodiment described on the basis of FIGS. 10 and 11, and there is only a difference. The silver punching blade 25a is arranged in a bar, and if a circular (ring-shaped) punching blade 25a is used in FIGS. 10 and 11, the electrode 10 for bolt welding according to another embodiment of the present invention In manufacturing, an arc-shaped punching blade 25a protruding at least two or more with a predetermined angle range along the periphery of the bottom surface of the punching rod 25 is used.

In other words, in the manufacture of the electrode 10 for bolt welding shown in FIGS. 12 and 13, the four arc-shaped punching blades 25a corresponding to each of the arc-shaped punching grooves 20 are provided with a punching rod ( The upper mold 24 formed radially protruding along the circumferential direction of the bottom of 25) is used, and when manufacturing the electrode 10 for bolt welding shown in FIGS. 14 and 15, it corresponds to each arc-shaped punching groove 20 Two or eight arc-shaped punching blades 25a that are formed at regular intervals are used to protrude radially along the bottom surface circumferential direction of the punching rod 25, and accordingly, the punching diameter ( D2) is the diameter provided by the virtual circle when each arc-shaped punching blade 25a having a radial arrangement structure is connected in a circle shape.

According to the present invention having the configuration as described above, the electrode body 11 is mounted on the lower mold 27 so that the bottom surface of the lower body 15 constituting the electrode body 11 faces upward, By lowering the punching rod 25 of the upper mold 24, a ring-shaped punching blade 25a provided on the bottom surface of the punching rod 25 or a plurality of arc-shaped punching blades 25a having a radial arrangement structure is lowered. By applying a press punching method that inserts into the bottom surface of the electrode body 11 along the circumference of the mounting hole 15b of the body 15 by a predetermined depth, hitting the hitting pin or hitting rod at an angle with a hammer or hammer Thus, the stopper structure of the insulator 12 can be formed very quickly, easily and economically than in the conventional case in which three to four caulking protrusions 16 were formed.

In addition, by providing a protruding support portion 21 in the form of a stopper structure pushed inward so that the peripheral portion of the mounting hole 15b of the lower body 15 supports the edge of the bottom surface of the insulator 12, Compared to the conventional caulking protrusion 16, the insulator 12 can be supported very firmly and stably, and in particular, only the upper portion of the protruding support portion 21 is wedge-connected with the edge of the bottom surface of the insulator 12. On the other hand, the remaining part of the protruding support part 21 is made to be rounded in a direction opposite to the direction in which the insulator 12 pushes the corresponding support part, so that the support strength of the insulator 12 can be further maximized. It is possible to provide a stopper with an optimal structure.

Through this, as defects such as cracks or deformations occur on the top surface of the electrode body 11 in the process of using the electrode 10 for bolt welding, the upper part of the electrode body 11 is made into an insulator through milling. In the work of removing the defective part by cutting it out by a certain amount together with (12), even if a strong pressing force to push the insulator 12 downward by a milling cutter acts, the protruding support part 21 does not have any deformation. Since it can firmly and stably support the corresponding pressing force without it, it is not only possible to greatly improve the recyclability of the electrode 10 by milling, but also the welding performance and the protection function of the bolt leg at the time of recycling. It can be maintained at the same level as

1: upper electrode 2: lower electrode 3: base material
4: bolt hole 5: bolt 6: bolt transfer table
7: support 8: elevating rod 9: welding protrusion
10: electrode 10a: insertion passage 11: electrode body
12: insulator 12a, 25b: inclined cutting surface 13: setting flange
14,17: upper body 14a: insertion hole 15,18: lower body
15a: fastening part 15b: mounting hole 16: caulking protrusion
19: locking jaw 20: punching groove 21: protruding support
22: support end 23: punching mold 24: upper mold
25: punching rod 25a: punching blade 25c: groove
26: punching guide 27: lower mold 28: setting hole
D1: hole diameter D2: punching diameter d1: clearance
d2: Protrusion width t1: Protrusion thickness t2: Insertion depth
θ: inclination angle

Claims (7)

Insertion passage 10a into which the insulator 12 is inserted and installed along the central axis direction of the cylindrical electrode body 11, and the leg portion of the welding bolt 5 is inserted along the central axis direction of the insulator 12 Is formed through, and the electrode body 11 is divided into an upper body 14 and a lower body 15 based on the setting flange 13 protruding along the outer peripheral edge of the center side, and the upper body 14 An insertion hole 14a of the leg portion of the bolt 5 through the insulator 12 is formed in the center of the upper surface of the lower body 15, and a screw-type fastening part 15a is formed at the outer periphery of the lower body 15, and the lower body A mounting hole (15b) for inserting the insulator 12 is formed on the bottom surface of (15), and the bottom surface of the lower body 15 is from the bottom surface of the insulator 12 by a predetermined protruding thickness (t1). Bolt welding provided with a stopper structure that protrudes and prevents the insulator 12 from coming out from the mounting hole 15b of the lower body 15 between the bottom surface of the lower body 15 and the bottom surface of the insulator 12 In the dragon electrode 10,
The stopper structure is formed in a ring-shaped punching groove 20 formed on the bottom surface of the lower body 15 along the circumferential direction of the hole with a certain clearance distance d1 from the mounting hole 15b of the lower body 15. The bolt, characterized in that the circumferential portion of the mounting hole 15b corresponding to the clearance distance d1 becomes a protruding support portion 21 pushed inward to support the edge of the bottom surface of the insulator 12 Welding electrodes. According to claim 1, The stopper structure is a minimum radially formed on the bottom surface of the lower body (15) along the circumferential direction of the hole with a certain clearance (d1) from the mounting hole (15b) of the lower body (15). Among the circumferential portions of the mounting holes 15b corresponding to the clearance distance d1 by two or more arc-shaped punching grooves 20, the circumferential portion in which the punching grooves 20 are formed is the bottom of the insulator 12 Electrode for bolt welding, characterized in that the protruding support portion 21 pushed inward to support the edge of the surface. The punching according to claim 1 or 2, wherein the punching groove (20) forms a concave cross-section from the bottom surface of the lower body (15) in a "∧" shape, and provides the protruding support (21). An electrode for bolt welding, characterized in that the inner circumferential surface of the groove 20 is bent roundly in the direction of the central axis of the electrode body 11. Insertion passage 10a into which the insulator 12 is inserted and installed along the central axis direction of the cylindrical electrode body 11, and the leg portion of the welding bolt 5 is inserted along the central axis direction of the insulator 12 Is formed through, and the electrode body 11 is divided into an upper body 14 and a lower body 15 based on the setting flange 13 protruding along the outer peripheral edge of the center side, and the upper body 14 An insertion hole 14a of the leg portion of the bolt 5 through the insulator 12 is formed in the center of the upper surface of the lower body 15, and a screw-type fastening part 15a is formed at the outer periphery of the lower body 15, and the lower body A mounting hole (15b) for inserting the insulator 12 is formed on the bottom surface of (15), and the bottom surface of the lower body 15 is from the bottom surface of the insulator 12 by a predetermined protruding thickness (t1). On the basis of the protruding bolt welding electrode 10, the insulator 12 is formed between the bottom surface of the lower body 15 and the bottom surface of the insulator 12 from the mounting hole 15b of the lower body 15. In the manufacturing method of the bolt welding electrode 10 for forming a stopper structure that does not come out,
An electrode setting step in which the electrode body 11 is mounted vertically on the lower mold 27, and the bottom surface of the lower body 15 faces upward, and the electrode set on the lower mold 27 By lowering the punching rod 25 of the upper mold 24 toward the electrode body 11, the punching blade 25a protruding from the bottom surface of the punching rod 25 in the form of "∨" It is made by including a punching molding step to insert a predetermined insertion depth (t2) through the bottom surface,
The punching blade 25a is formed to protrude in a circular shape along the circumference of the bottom surface of the punching rod 25, and the punching diameter D2 by the punching blade 25a and the mounting hole on the bottom surface of the lower body 15 ( By providing a predetermined clearance gap (d1) between the hole diameters (D1) by 15b), the peripheral portion of the mounting hole (15b) corresponding to the clearance gap (d1) is subjected to a punching molding step and an insulator ( 12) A method of manufacturing an electrode for bolt welding, characterized in that it is formed into a protruding support part 21 pushed in the inward direction to support the edge of the bottom surface of 12). According to claim 4, The punching blade (25a) is formed to protrude in an arc shape with a predetermined angular range along the periphery of the bottom surface of the punching rod (25) in a number of at least two, and the punching The diameter (D2) is characterized in that each arc-shaped punching blade (25a) is provided by a radial arrangement structure in the form of surrounding the mounting hole (15b) of the lower body (15) with a predetermined clearance distance (d1). Method of manufacturing an electrode for bolt welding. The method of claim 4 or 5, wherein the clearance gap (d1) provided between the punching diameter (D2) and the hole diameter (D1) is in the range of 0.5 to 1.5 mm, and the bottom of the insulator (12) The protruding thickness (t1) of the bottom surface of the lower body 15 based on the surface is within the range of 0.8 to 2mm,
The insertion depth t2 of the punching blade 25a is within a range of 1/2 to 4/5 of the bottom protruding thickness t1 of the lower body 15, and the inclination angle of the outer surface of the punching blade 25a ( θ) is within the range of 0 to 10 degrees, while the inclination angle of the inner side of the punching blade (25a) is within the range of 30 to 60 degrees, characterized in that the manufacturing method of a bolt welding electrode. The method according to claim 4 or 5, wherein the bottom surface of the punching rod 25 corresponding to the inner side of the punching blade 25a has a spherical shape connecting with the sharp tip of the lower end of the punching blade 25a. Method of manufacturing an electrode for bolt welding, characterized in that the groove (25c).

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