JP2007152360A - Spot welding electrode elevating in vertical attitude - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical welding electrode capable of performing the spot welding inside a metal casing, a metal container, a switchboard or the like in the field of the metal plate working without any trouble. <P>SOLUTION: A spot welding electrode is a vertical bar-shaped welding gun 200 of one electrode out of a pair of electrodes for performing the resistance welding with a work W to be welded therebetween. A projecting relief part 400 is provided at least in a part thereof, a holder member 110 is mounted with at least a part of the relief part as a mounting face, and a welding tip 210 at the tip end of the vertical bar-shaped welding gun 200 is held by the holder member 110, and located on the vertical line common to the welding tip 210 and the vertical bar-shaped welding gun 200. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrode for spot welding in a vertical orientation, and more specifically, a welding electrode for welding a workpiece made of a metal material or the like by locally sandwiching an object to be moved up and down in a vertical orientation and applying pressure. This is a welding electrode that can be welded by moving it up and down in a vertical orientation even when the welding spot is inside the workpiece.

  Conventionally, when welding materials to be welded such as various metal plates, such as rolled steel plates, aluminum and their alloy materials, and Zn-plated steel plates, at least two or more materials to be welded are stacked on top and bottom electrodes. Spot welding is used in which welding is performed by squeezing, pressurizing and energizing, forming a nugget and welding, and is currently one of the most popular welding methods using electric energy. In addition to the automobile industry, it is widely used in fields called metal processing and sheet metal processing.

  Generally speaking, in spot welding, one spot welding can be performed in a few seconds, and welding is performed between workpieces, so that no other shield gas or the like is required. Once the welding conditions are set, welding can be easily performed even by completely amateur people or robots. There is an advantage that a stable weld nugget and joint strength can be obtained. Therefore, it is widely used in general metal processing as well as a joining means in a mass production system of automobiles and the like.

  However, spot welding is performed using a welding gun that moves up and down in a vertical orientation to obtain a high applied pressure. Therefore, when there is a welding point inside the work piece and the resulting structure, There is a drawback that some of them can not be welded because they become obstacles when moving up and down.

That is, in a spot welder, the welding electrode that moves up and down in a vertical orientation is
(1) supplying a large welding current to the welding spot to be welded;
(2) Giving high welding pressure to the welding spot to be welded;
(3) cooling the surface of the welding spot to be welded;
It has a purpose such as.

For this reason, during welding, the current density of the electrode is as high as 100 to 500 A / mm ² , and the pressure ranges from 5 to 12 kgf / mm ² . In order to obtain such a high pressure, it is absolutely necessary to raise and lower the electrode in an upright position without any obstacles.For example, when there is a welding spot inside the work piece such as a box or a container, It is said that it cannot be welded.

  Therefore, as described above in the specification of Japanese Patent No. 3445636, the present inventors have made an upper welding electrode configured in a rod shape among upper and lower welding electrodes that sandwich a material to be welded from above and below. On the other hand, a spot welding machine is proposed in which the lower welding electrode is formed as a flat and conductive table on the surface, and welding can be performed with the work piece set on the table-like electrode. did.

  This table type spot welding machine uses the welding gun of the upper electrode in a horizontal orientation, and uses it by levering this rod-like electrode, so there is a welding spot inside the work piece. Also, it is possible to infiltrate a welding gun in a lateral orientation. However, it is preferable that this table type spot welder can apply a downward pressure using a lever mechanism called a lever mechanism. However, there is a drawback in that the structure is hindered and a high pressure cannot be obtained.

  Also, a high pressure is applied to the tip of the welding gun that moves up and down in a vertical orientation, that is, the welding tip, and it gradually crushes and deforms as the number of welding points progresses, and the contact surface of the electrode tip is alloyed. Causes dirt (pick up). For this reason, when the number of spot welds reaches a point where the welding quality or work efficiency is affected, it is necessary to replace it with a new welding tip or welding electrode when the life of the electrode is reached.

  However, it takes a lot of work to replace and replace the welding tip. That is, the welding tip and the welding electrode are exposed to an adverse condition of pressurization at a high temperature. Therefore, the welding tip and the welding electrode to be replaced are deformed and seized, and it takes a lot of trouble to remove the welding tip. There is a disadvantage that it takes.

To explain further, the welding tip is directly involved in cooling the surface of the welded portion, the cooling water leaks due to the deformation of the welding tip, and such improvements have been made to the welding gun tip, particularly the welding tip mounting structure. It is hoped that
Japanese Patent No. 3445636

  An object of the present invention is to solve the above-mentioned drawbacks. Specifically, in a welding electrode in a vertical orientation used for energizing and pressing a steel plate or other metal plate, a convex bow is formed on a part thereof. Vertical welding that removes obstacles due to the structure of the work piece by this bald part and can be welded by raising and lowering the welding electrode in a vertical position even at the welding spot inside the work piece Propose electrodes.

  That is, according to the present invention, among the pair of electrodes that are resistance-welded across the material to be welded, at least a part of the vertically-oriented bar-shaped welding gun of one electrode is provided with a convex ridge, and at least one of the ridges is provided. A holder member is attached with the portion as an attachment surface, and the welded portion at the tip of the vertical bar-shaped welding gun is held by this holder member so as to be positioned on a common vertical straight line with the vertical bar-shaped welding gun.

  As described above, since the welding electrode according to the present invention, that is, a part of the welding gun is provided with a convex portion as a bow portion, even if a part of the work piece becomes an obstacle during welding, the obstacle part Since it is absorbed by the bald part, it can be welded without any problem. In addition, a holder member can be detachably attached to the protruding convex protrusion using this, and a welding tip or the like can be attached to the holder member. It is possible to achieve the replacement of welding without any trouble.

  Therefore, a preferred embodiment of the present invention will be described as follows through the accompanying drawings.

  In addition, FIG. 1 is a front view which shows a part of welding electrode which concerns on one Example of this invention in a cross section.

  FIG. 2 is an enlarged cross-sectional view of a part of FIG.

  FIG. 3 is an assembly diagram of an example of a holding device such as a welding tip provided on the welding electrode shown in FIG.

  FIG. 4 is an explanatory view showing a part of FIG. 2 in an enlarged manner.

  First, in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, reference numeral 200 indicates a welding electrode, that is, a welding gun according to one embodiment of the present invention, and reference numeral 100 is provided on a part of the welding gun 200. A reference numeral 300 denotes a table-like electrode that serves as an example of a lower electrode, and a reference sign W denotes a material to be welded. In this holding device 100, reference numeral 110 denotes a holder member, 120 denotes a ring body, and 130 denotes a set screw.

  A welding gun 200 indicated by reference numeral 200 in FIG. 1 and a part of which is shown in FIG. 2 is used in a vertically oriented posture and is configured to be movable up and down. For example, the welding gun 200 is welded by urging an air cylinder (not shown). A high pressing force is applied to the material W. The welding gun 200 sandwiches the material W to be welded from above and below with the corresponding table-like electrode 300, and pressurizes and applies resistance welding.

  In addition, as shown in FIG. 2, this to-be-welded material W is comprised with the steel plate combined like a metal container or a metal box, for example. For this reason, a welding spot exists in the inside. Therefore, it is said that if the welding gun is configured in a straight line like the conventional welding gun, a part of the workpiece W is obstructed when it is raised and lowered, and welding cannot be performed.

  The welding gun 200 is connected to one pole of a welding power source (not shown) and serves as an upper electrode, while a table electrode 300 connected to the other pole of the welding power source as a lower electrode is formed thereon. Spot welding is performed by placing the workpiece W on the workpiece, changing the welding spot sequentially without moving as the welding spot progresses, and sequentially hitting the welding spot with the welding gun 200 serving as the upper electrode. be able to.

  Although the embodiment shown in FIG. 4 uses the table-like electrode 300 as the lower electrode, it is not always necessary to configure it as a table-like electrode. It can be configured as a rod-shaped welding electrode as in the conventional stationary welding machine. However, as shown in FIG. 4, in the case of the table-like electrode 300, the corner portions of the workpiece W are sequentially welded while the workpiece or workpiece W is placed on the welding electrode. it can.

  That is, any part of the surface of the table-like electrode 300 is energized, and when it is struck with the welding gun 200, it can act as a spot electrode. Can be welded without moving.

  On the other hand, the rod-like welding gun 200 constituting the upper electrode can be constructed as long as it has a welding tip 210 at the tip, but even if this welding tip 210 is fitted to a desired shank member 220. Can be configured.

  That is, the welding gun 200 shown in FIG. 1 and a part thereof is shown in FIG. 2 includes a welding gun main body 230 and an intermediate member 240, which are fitted together and joined. For this reason, the intermediate member 240 can be replaced and welded according to the position of the welded portion and the shape of the workpiece W as desired.

  Thus, the welding tip 210 is provided at the tip of the intermediate member 240 joined to the gun body 230, and the welding tip 210 is attached via the shank member 220. However, in some cases, the welding tip 210 itself can be directly attached to the intermediate member 240. However, if the shank member 220 is interposed at the tip of the welding gun 200, for example, as shown in FIG. 2, the shank member 220 may be slightly offset, and the position of the welding tip 210 is set by the offset. It can be slid.

  As described above, in the welding gun 200 that serves as an upper electrode for resistance welding the workpiece W from above and below, the convex portion 400 is provided at least as a convex shape. As shown in FIG. 2 in an enlarged manner, the bent portion 400 is formed by protruding a part of the welding gun 200, particularly, a part of the intermediate member 240. As shown in FIG. Is formed. Along with the provision of the bent portion 400, a part of the welding gun 200 becomes deformed and convex, but the welding tip 210 and the welding gun 200 provided at the tip of the intermediate member 240 as a whole, especially the gun body 230, Are positioned on a common vertical straight line.

  It is generally preferred that the welding gun working in a vertical orientation is generally straight. The reason for this is that pressure is applied through the vertical axis, so that if the point of action of the welding gun is moved sideways, stress such as bending or twisting is applied to that extent, and the tip of the welding tip 210 is attached to the workpiece W to be welded. Can not contact the surface on average. The strength of the formed weld is deteriorated.

  On the other hand, when the present inventors examined, even if it provided a bow part in the middle part, as a whole, especially the gun body 230 of the power point to which a vertical load acts, and the welding tip 210 of a load point, It has been found that when they are on the same axis, a pressurizing force is applied on average and a weld having a constant strength can be obtained.

  In short, even if the bald portion 400 is provided, if the strength of the portion is such that the portion is not crushed and broken, and the offset ratio is not so large, an average vertical force is applied to the entire contact surface of the welding tip 210. It can be added and weldability is not impaired.

  Further, in an electrode used in a vertical orientation in spot welding, the convex bow 400 is not shown in the figure in place of the U shape shown in FIGS. 1 and 2, but is bent into a polygonal shape. It can also be configured.

  Further, the convex bent portion 400 is configured to be bent in a U shape, but in the convex bent portion 400, at least a part of the bent portion of the cooling water flow path formed therein is configured in an arc shape. You can also That is, a bent portion is formed in the internal cooling water flow path along with the formation of the bent portion 400, and the flow velocity changes greatly between the inside and the outside of the cooling water flow by the bent portion. This change lacks the uniformity of the cooling capacity, and this is preferable because it can be mitigated by forming the arc portion.

  Further, by providing the convex ridge portion 400, a planar mounting surface can be provided on at least a part of the outer surface. A holder device 100 such as a welding tip made of a holder member, which will be described later, can be detachably attached via this attachment surface. According to the holder member, the distal end portion of the welding gun 200 can be pressed and held from the periphery, and when the welding tip or the like is exchanged or seized, the welding tip or the like can be removed simply by removing the holder member. Further, the holder member can be screwed to the mounting surface of the bald portion 400 in a convex shape, and can be configured to be detachable simply by removing the screw.

  In the welding gun 200 configured as described above, if a part of the welding gun 200, in particular, the intermediate member 240 itself is configured to have a convex portion 400 as shown in FIG. The holding device 100 can be detachably attached via the surface, and further, the intermediate member 240 including the bald portion 400 can be replaced and welded only when the welding tip 210 is offset and welded.

  The holding device 100 is for holding the welding cap 210. The holding device 100 is provided with a holder member 110. The holder member 110 is formed of a plate-like material, and a part of the holder member 110 is provided. A fitting hole 120 is formed, and a welding tip 210 or a shank member 220 interposed in the fitting hole 120 is fitted into the fitting hole 120 so as to be freely inserted and removed.

  When the welding cap 210 is attached to the tip of the welding gun 200 via the holding device 100 in this way, the holding device 100 is involved in the attachment of the welding cap 210, and the holding device 100, particularly the holder member 110 is removed. Since only the welding tip 210 can be replaced, the replacement is very easy. However, when the replacement mechanism is configured in this way, it is necessary to prevent leakage of cooling water or the like from the holding device 100 of the replacement mechanism. From this point, a ring groove 121 is provided around the fitting hole 120 of the holder member 110 made of a plate-like material, and the ring body 130 is seated in the ring groove 121, and the ring body 130 is fitted into the fitting hole 120. The shank member 220 is preferably configured to be tightened.

  In addition, the holder member 110 is configured to be detachable in the welding cap holding device 100, and at the tip of the welding gun 200, an attachment surface is formed at a part thereof, and the holder member 110 is disposed on the removal surface. It can also be screwed.

  Further, the welding gun 200 is configured by dividing the welding gun main body 230 and the holder portion 240, and as the mounting surface is provided on a part of the holder portion 240, the inside of the holder portion 240 is related to the mounting surface. A cooling water passage 241 can be formed. When the cooling water passage 241 is formed in the holder part 240 divided in this way, the clogging in the cooling water passage 241 can be prevented by opening the plug member 242 that closes this portion.

  As described above, the present invention is provided with a convex bald portion on at least a part of a vertical rod-shaped welding gun that works as one electrode in a vertical posture when resistance welding is performed across a material to be welded. A holder member is detachably attached using a barb portion, and the welded portion at the tip of the welding gun is held by this holder member. Such a vertical electrode is generally used for spot welding, and in particular, metal It can be used in a field called box processing, distribution board and so-called sheet metal processing.

It is a front view which shows a part of welding electrode which concerns on one Example of this invention in a cross section. It is a partial expanded sectional view of FIG. It is an assembly drawing of an example of holding devices, such as a welding tip provided in the welding electrode shown in FIG. It is explanatory drawing which expands and shows a part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Holding device 200 Welding gun 230 Gun main body 300 Sheet-like electrode 400 Convex bow part W Material to be welded

Claims (7)

  Of the pair of electrodes to be resistance-welded across the material to be welded, at least a part of the vertical bar welding gun of one electrode is provided with a convex bulge, and at least a part of the bulge is used as an attachment surface. According to the vertical posture, the holder member is mounted, and the welded portion at the tip of the vertical bar-shaped welding gun is held by the holder member so as to be positioned on the same vertical straight line as the vertical bar-shaped welding gun. Spot welding electrode.   The spot welding longitudinal electrode according to claim 1, wherein the welded portion is composed of a welding tip that contacts a workpiece or a support member that supports the welding tip. electrode.   The spot welding electrode according to claim 1 or 2, wherein the vertical electrode for spot welding is formed by bending the convex portion into a polygonal shape.   4. The spot welding electrode according to claim 1, wherein the spot welding longitudinal electrode is formed by bending the convex portion into a U-shape.   5. The spot-oriented spot according to claim 1, wherein at least a part of the bent portion of the convex bald portion is formed in an arc shape in the vertical electrode for spot welding according to claim 1, 2, 3, or 4. Welding electrode.   In the vertical electrode for spot welding according to claim 1, 2, 3, 4 or 5, the mounting surface of the convex portion is configured to be planar while the holder member is configured to be a plate-like material, An electrode for spot welding according to a vertical orientation, characterized in that the holder member holds the welding portion at the tip of the welding gun by pressing from the periphery.   7. The spot-oriented spot according to claim 1, wherein the holder member is configured to be detachable by screwing the holder member onto the mounting surface of the convex portion in the vertical electrode for spot welding according to claim 1 or 6. Welding electrode.

Images