JP2007203318A - Spot welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide spot welding equipment where, using a welding gun in a horizontal posture as a lever, steel sheets or the other metal sheets as the objects to be welded are subjected to pressure energizing on the planar table electrode, so as to be welded. <P>SOLUTION: The spot welding equipment is composed in such a manner that a supporting unit 200 for supporting a welding gun 110 moving along a substrate 210 as a lever moves together with the welding gun, and is provided with: a spot welding machine body 100 where the heel part of the welding gun 110 supported as a lever is pushed up by an energizing pressure rod 220 supported in the supporting unit 200 so as to be freely ascendable/descendable, and the materials W to be welded are subjected to pressure energizing by the tip part of the welding gun 110, so as to be welded; and a pressurizing device 300 where the heel part of the energizing pressure rod 220 is pushed up upward, so as to be pressurized in the moving position of the supporting unit 200. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spot welding apparatus. More specifically, the present invention relates to a spot for welding a material to be welded, such as a steel plate or other metal plate, on a plate-like table electrode by using a welding gun in a horizontal position. It is a welding device, and in particular, this welding gun is used in combination as a welding current energization path and a pressurizing means, reducing the energization cable to the welding gun with little use, etc. In addition to streamlining, the welding gun itself is used in a horizontal position to increase the applied pressure and eliminate the obstacles to electrical conductivity and weldability caused by the arc motion of the tip welding tip that occurs when using the welding gun. The present invention relates to a spot welding apparatus that is improved.

  In metal processing, particularly sheet metal processing, a spot welding apparatus is widely used that generally welds metal materials such as metal plates to be welded and superposed on each other without applying a filler material. A spot welding device is said to be a spot welding device or a spot welding machine because the welded portion to be formed is a spot or spot. From the point of pressure welding using resistance heat generated by energization as a heat source, pressure welding and fusion welding are performed. It is one of the resistance welding equipments called fusion of, and is widely used in the manufacture and manufacture of sheet metal structures such as boxes and frames.

  For this reason, various types of spot welding devices have been proposed for each application, but large-sized ones are often used for mass production of automobile bodies. Most of what is called a small stationary type is used for sheet metal processing of rods. The former large one has seen a great technological improvement with the development of the automobile industry, and it has been developed according to the model as a dedicated machine in the field of automobile body manufacturing with a lot of model changes, and rapid progress improvement is I'm addicted. On the other hand, in the field of sheet metal processing of workpieces of the latter type of small rods of many types, what is called a stationary spot welder is used, and the use method of the welder is changed according to changes in the type, without improvement. For several decades, stationary spot welders with almost the same structure have been used as they are.

  That is, the stationary spot welding machine is a type of welding machine in which two materials to be welded are overlapped, and these are sandwiched by a pair of upper and lower bar-shaped electrodes from above and below, and pressurized and energized. The welding principle is the same for large-sized car body welding machines and manual welding machines. In short, two materials to be welded are sandwiched between upper and lower electrodes, and welding is performed by applying a pressing force and a welding current. In particular, it is a welded joint that supplies a large amount of current in a short time to form an arcuate weld, i.e., a so-called nugget. Therefore, the upper and lower electrodes are both rod-shaped to reduce the pressure applied current area to the work piece. Welding is performed with increased pressure and current.

  As described above, the large spot welder and the stationary welder incorporated as part of a production line for automobile bodies and the like use the same welding principle. Nevertheless, robots and even automation have been achieved in the fields of automobile body manufacturing, etc., due to the remarkable development of parts to be welded and jigs such as assembly, transport and welding. On the other hand, stationary spot welders used for so-called sheet metal processing have not been improved at all, and there has been no development or improvement of the required jigs. It is manually operated depending on experience and skill.

  Specifically, in the field of sheet metal processing, there are parts that should be welded inside, such as metal frames and metal boxes, and the welded parts cannot be pressurized directly from the outside, or products of various types of small rods. Many of them have completely different structures and models. In such welding of workpieces and materials to be welded, it is difficult to make a line as in automobile manufacturing equipment. Welding manually.

  In any case, some of the complex-shaped structures are welded inside. When welding such a structure, the upper electrode, called a welding gun, should be faced down in a vertical position. It is difficult to operate the electrode by lowering and welding. When welding is to be performed by raising and lowering the welding gun, the work to be welded is stabilized by human power, and this work is extremely heavy labor. It is. In addition, the welding tips at the tips of the upper and lower electrodes are configured to have a narrowed shape in order to obtain a high current and a high pressure. Even if it is an operator, a welding flaw, a welding post, etc. remain in a welding part inevitably. The task of removing this is extremely complicated and is one of the major heavy labors, which increases the welding costs.

  From this point, the present inventors first responded to each welded part even if it is a structure with a small rod and a complicated shape, especially a structure with a welded part to be welded inside. We have proposed a spot welding device that can be welded by selecting a welding position, and that can also achieve work such as processing and assembly accompanying welding. (Refer to the specification of Japanese Patent No. 3445636)

  This spot welder 1 is as shown in FIG. 3, and the lower electrode 2 is constructed as a so-called table electrode or sheet-like electrode made of a flat conductive plate material. It is. The spot welder 1 can process and assemble a workpiece W such as a metal material on a sheet electrode 2. In this spot welding machine 1, the welding gun 3 is lowered in a vertical posture toward the workpiece W placed on the table electrode 2, and the workpiece W is moved to the table electrode 2 and the welding gun 3. In this apparatus, the welding gun 3 is supported by a telescopic support beam 4 and a support arm 5, and the welding gun 3 is free on the table electrode 2. The welding gun 3 is moved by the expansion and contraction of the support arm 5 so that the welding gun 3 is lowered when the welding hit point is reached and welding can be performed.

In the spot welder 1, the surface of the table electrode 2 used as the lower electrode can be used as a work surface and is energized over the entire surface. Even if it exists, it is not necessary to move the to-be-welded object and workpiece which function as an electrode, and it can be welded by moving the welding gun 3 by the expansion / contraction operation of the support arm 5 while it is placed. Since a cooling water passage can be provided over the entire surface of the table electrode, a large amount of cooling water can be circulated, the cooling capacity is extremely large, and the pressure applied during welding is distributed and supported on the surface of the table electrode 2. Because it can be done, there are no weld marks. Furthermore, since the welding gun 3 forms one part of the lever mechanism in the lateral orientation, the welding force is increased and the pressure is increased, so that a weld joint having high strength can be obtained.
Japanese Patent No. 3445636

  However, the previously proposed spot welding equipment has the same benefits as above, and can be welded without moving the workpiece to be welded at each welding point, and a large pressure is applied by the booster mechanism. It is. Since this welding device has a structure in which a welding gun is used and a downward pressure is applied to flow an electric current, the welding gun tip is not lowered vertically with respect to the workpiece, and the welding gun that forms the lever is its pivot. Since the welding gun tip descends by pivoting around the fulcrum, the welding gun tip does not descend vertically but descends while drawing an arcuate locus, so the applied pressure is applied to the work piece in an inclined manner rather than perpendicularly. Yes. In addition, the welding gun is connected to various facilities such as a pressurizing mechanism, power supply wiring, and cooling water supply piping. These facilities are to be hung on the table electrode to suspend them. The above-mentioned support beam and support arm are required, and there is a disadvantage that the equipment is enlarged.

  Furthermore, since the lower electrode is also a table type and uses it as a work surface, it will take up a lot of space, especially expensive copper and special copper alloys (eg chromium copper). Therefore, there is a problem that the cost is increased and the weight is increased. Improvement in this aspect is desired.

  The present invention has been made to solve the above-mentioned drawbacks, and is constructed so that a support unit that supports the welding gun moving along the substrate can move together with the welding gun and is supported by the welding gun. A spot welder main body that pushes up the rear end of the gun with a current-carrying pressure rod that is supported so as to be movable up and down in the support unit, and pressurizes and welds the material to be welded with the front end of the welding gun; A pressure device that pushes and presses up the rear end portion of the energizing pressure bar in the moving position, and the pressure device has a length corresponding to the moving range of the support unit and is energized. A push-up member that pushes up and pressurizes, a push-up pressurization source that is mounted substantially at the center of the push-up member, and a support frame that supports the push-up pressurization source together with the push-up member so as to be movable up and down This support frame body Is provided with a guide column attached to the push-up member so as to be positioned in parallel on both sides of the push-up pressurization source and a support plate for supporting the push-up pressurization source up and down by these guides. The lower end of the guide column is bridged by a connecting plate, and the support frame is formed into a square or cubic shape.

  Therefore, this welding apparatus is supported by the supporting unit that moves along the substrate so that the welding gun can be rotated. Since the lever mechanism for levering the welding gun is provided, the pressure applied during welding can be greatly increased. In addition, this lever mechanism is configured so as to be able to supply pressure and welding current by contacting the rear end of the welding gun and the energizing pressurizing rod, so that the cooling water pipe, energizing cable, pressurizing source ( It is not necessary to suspend the air cylinder or the like on the table electrode, the structure is extremely compact, and ultimately the economic efficiency of the product can be improved. Furthermore, since the energizing pressure bar and the pressure source are supported by a support frame that is framed in a box shape, etc., the energizing unit can be energized when the welding gun moves anywhere on the board together with the support unit. The pressure bar can always apply pressure and welding current to the welding gun in a vertical state, and a uniform weld (that is, a nugget) can be formed.

  In addition, in the spot welding apparatus in which the tip of the welding tip moves down along the circular arc track, a horizontal component force is generated due to the welding tip descending along the circular arc track. When the energizing and pressing rod moves to a position that does not match the direction of the applied pressure from the pressure source, an external force such as bending and twisting acts on the lower end of the energizing and pressing rod, causing the energizing and pressing rod to slide sideways. Even if the sliding is slight, the lower end of the energizing pressurizing rod moves in the lateral direction, so that the applied pressure and welding current cannot be constantly supplied from the energizing pressurizing rod to the welding gun without any trouble. However, since the energizing and pressing rod is framed as a support frame including a push-up member that supplies the pressing force, the pressing force and the welding current can be constantly supplied without slight fluctuation.

  Therefore, the configuration and operation of these means will be specifically described with reference to the drawings as follows.

  In addition, FIG. 1 is explanatory drawing which shows the spot welding apparatus based on one Example of this invention.

  FIG. 2 is an explanatory view of a support frame in the spot welding apparatus shown in FIG.

  FIG. 3 is an explanatory view of one conventional spot welder.

  First, as shown in FIGS. 1 and 2, in a spot welding apparatus according to one embodiment of the present invention, reference numeral 100 is a spot welder body, 110 is a welding gun, 120 is a table electrode, 200 is a support unit, 210 is a substrate of the support unit, 300 is a pressurizing device, 400 is a support frame, W is a material to be welded, and the spot welding apparatus according to the present invention includes a support unit 200, a pressurizing device 300, A support frame 400 that supports the pressure device 300 is incorporated. Thus, these points will be described in order as follows.

  As shown in FIG. 1, in the spot welder main body 100, a material W to be welded such as a steel plate is placed on a table electrode 120 that forms a lower electrode, and a welding gun 110 is placed on a predetermined welding spot (welded part). The welding tip 111 at the tip is lowered and welded.

  The welding gun 110 is configured to be movable in the horizontal direction along the substrate 210 together with the support unit 200 described later with respect to the table electrode 120. The table electrode 120 for welding the workpiece W on the surface is the substrate 210. The support unit 200 is configured separately. Although not shown, the table electrode 120 is connected to one pole of the welding power source, and the other pole is connected to an energizing and pressing rod 220 that is supported by the support unit 200 so as to be movable up and down.

  Next, the welding gun 110 is rotatably supported by the support unit 200 in the horizontal posture, moves along the substrate 210, and constitutes a lever.

  That is, the welding gun 110 includes a welding tip 111 at the tip, a shank member 112, a holder member 113, a cooling water conduit 114, and a handle 115, and a pivot shaft 230 at the tip of the support arm by the support unit 200 described later. It is supported rotatably via In short, the welding gun 110 is supported by the support unit 200 by rotating about the pivot shaft 230, and the welding gun 110 can move together with the support unit 200.

  In this way, the supporting unit 200 that is supported by the welding gun 110 is configured so that the substrate 210 can move on the substrate 210 in a straight line, that is, in the lateral direction toward the paper surface of FIG. 1, and the welding gun 110 is placed at a predetermined spot. When moving to the position, the support unit 200 can be moved by the operation of the handle 115 to perform linear positioning. Since the support arm is pivotally supported by the support unit 200, the welding gun 110 rotates together with the support arm and can be positioned in the width direction with respect to the workpiece W.

  Next, as described above, the rear end portion of the welding gun 110 configured to be movable in the linear direction and rotatable in the width direction is pushed up by the energizing and pressing rod 220 supported so as to be movable up and down in the support unit 200. The material W to be welded is pressurized and energized by the tip of the welding gun 110.

  More specifically, the energizing and pressing rod 220 is made of an aluminum alloy in the same manner as a welding gun and the like, and is not simply a pressing means but an energizing means. A welding current is applied. On the other hand, the contact point of the rear end of the welding gun 110 is a leverage point, and a predetermined pressurizing force is applied to the workpiece W as a pushing force of the energizing and pressing rod 220.

  Next, in the spot welder main body 100 configured as described above, in the support unit that supports the welding gun 110 so as to be linearly movable on the substrate 210, the energizing and pressing rod 220 is pushed upward at the moving position. A pressurizing apparatus 300 for pressurizing is provided. The pressurizing device 300 can be configured in any way as long as the energizing pressurizing rod 220 can be pushed upward to pressurize it. However, as shown in FIG. 2, the pressurizing device 300 is configured to include a push-up member 310 and a pressurizing source 320. Are integrally supported by the support frame 400 so as to be movable up and down.

  In other words, the push-up member 310 that pushes up and presses the energization pressure rod 220 is configured as a long material having a length corresponding to at least the moving range of the support unit 200. A push-up pressurizing source 320 is attached to a substantially central portion of the push-up member 310, and the push-up member 310 is moved up and down. The pressurizing source 320 is usually preferably composed of a piston / cylinder mechanism such as an air-cylinder. When the pressurizing source 320 is configured as a cylinder / piston mechanism, the push-up member 310 is connected to the tip of the piston 321 via a locking member 322. Is preferably engaged. In this case, it is preferable that the locking member 322 is engaged with the tip of the piston 321 with a slight gap so as to be able to absorb the impact applied during pressurization.

  The push-up member 310 having the push-up pressurization source 320 attached to the center is supported by the support frame 400 so as to be raised and lowered. That is, the push-up member 310 is lifted by the extension of the piston 321 of the pressurizing source 320, and the energizing pressurizing rod 220 is pushed upward by the lift, and the welding gun 110 is pivotally supported at the tip of the support arm of the support unit 200. It rotates around the shaft 230 and is pressure welded by the welding tip 111 at the tip. Accordingly, the support frame 400 moves up and down together with the push-up member 310, and at the same time, when the energizing pressure rod 220 is removed from the axis of the piston 321 due to the movement of the welding gun 110 (see FIG. 2), the push-up member 310 is moved. A bending moment is exerted on the lower end of the upper energizing pressure rod 220 by the pushing force of the piston 321, thereby causing the energizing pressure rod 220 to slide laterally, thereby causing the welding tip 111 at the tip of the welding gun 110 to also slide. The nugget is not formed at the predetermined position. From this point, the push-up member 310 that moves up and down is supported by the support frame 400, and the support frame 400 includes the push-up member 310 and is configured in a frame with the guide column 410 and the connection plate 420. A support plate 430 is incorporated as a part, and the cylinder 323 of the pressurization source 320 is attached by the support plate 430 to support the pressurization source 320.

  More specifically, the push-up member 310 is provided with a pair of guide struts 410 and is formed in a gate shape. Along with this, a support plate 430 is movably interposed between the guide struts 410 and the lower end. The parts are bridged by a connecting plate 420 to form a rectangular frame. With this configuration, when the pressurization source 320 of the air cylinder mechanism is supported by the movable support plate 430, for example, through holes are formed at both ends of the support plate 430, and guide struts are formed in the through holes. Since the support plate 430 is inserted into the support plate 430, the guide column 410 extends as the piston 321 extends, and the push-up member 310 can be raised.

  Further, the lower end portion of the guide column 410 is bridged by the connection plate 420. The push-up member 310 is combined with a pair of guide posts 410 to form a gate shape, and pushes up the central portion of the gate-type frame to apply pressure, and the support plate 430 and A connecting plate 420 is attached and a square or cubic frame is set to strengthen the structure.

  That is, when an applied pressure is applied as the upward lifting force of the push-up member 310, the interposed energizing / pressing rod 220 moves linearly on the push-up member 310, and the push-up member 310 and the energizing / pressing rod 220 are internally connected. In addition to the upward pushing force transmitted as a shearing force, moment force such as bending and twisting acts, and in addition to the upward pressing force perpendicular to the pushing member 310 and the energizing pressure rod 220, A sliding force acts. Even if the direction in which the upward lifting force is applied does not coincide with the direction of the pressure applied by the energizing pressure rod 220, both ends of the lifting member 310 may be fixed, so that the average is constant. The vertical pressurizing force is given, and it is possible to absorb almost any slip in the lateral direction.

  More specifically, in the spot welding machine having the above-described configuration, the welding gun 110 and the energizing / pressing rod 220 are generally housed in the support unit 200. As long as the pressurizing source 320 that applies force is moved, the pressurizing source 320, in particular, coincides with the axis of the piston 321 and the energizing pressurizing rod 220, and supplies the welding pressure and welding current from the energizing pressurizing rod 220. Transmission can be performed under substantially constant conditions. However, the movement of the heavy pressure source 320 is structurally complicated and requires a strict synchronization mechanism for the movement of both, which is not preferable.

  From this point, a push-up member 310 having a length capable of being pushed and pressed at the moving position of the support unit 200 is provided, and a certain position, preferably approximately the center of the push-up member 310 is pushed by the pressure source 320. It is configured so as to apply an upward pressing force, and the obstacle caused by this configuration is squarely formed by pushing the lifting member 310, the pair of guide columns 410, the intermediate support plate 430, and the connection plate 420 as described above. There is one feature that is removed in the framework.

  The length of the guide bush 440 is preferably set to a length corresponding to 1/2 to 1/3 of the length of the guide column 410 in consideration of the lifting stroke of the piston 321.

  Further, any of the guide bushes 440 having a large section modulus can be configured, for example, as a tubular object. When the guide bush 440 is generally formed in a columnar shape or a cylindrical shape, the guide bushing 440 has a diameter of about 20 to 30 centimeters. preferable.

  Further, it is preferable that the push-up member 310 has at least two layers, and an insulating layer 311 is interposed between these layers.

  The insulating layer 311 is made of a plate-like material, and the insulating layer 311 can be made of a synthetic resin layer such as a vinyl chloride sheet or a foamed resin sheet.

  As is clear from the above configuration, a sheet-like table electrode is used as the lower electrode, and the welding gun as the upper electrode is a welding device that can move freely, and can be applied mainly to welding of various types of small rods. Since the material to be welded does not need to be moved for each welding spot, even a large material can be welded.

It is explanatory drawing which shows the spot welding apparatus which concerns on one Example of this invention. FIG. 2 is an explanatory view of a support frame in the spot welding apparatus shown in FIG. It is explanatory drawing of one spot welder of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Spot welder main body 110 Welding gun 200 Support unit 210 Substrate 220 Energizing pressurizing rod 300 Pressurizing device 310 Pressing member 320 Pressurizing source 400 Support frame 410 Guide strut 420 Connecting plate 430 Supporting plate W Welded Material

Claims (6)

  A support unit that supports the welding gun moving along the substrate is configured to move together with the welding gun, and the rear end of the welding gun supported by the welding gun can be moved up and down in the support unit. A spot welder main body for welding by pressing and energizing the workpiece to be welded by the tip of the welding gun after being pushed up by the current-carrying pressure bar supported, and the rear end of the current-carrying pressure bar at the moving position of the support unit A pressurizing device that pushes and presses the upper portion upward, and has a length corresponding to the moving range of the support unit and pushes and pressurizes the energizing pressurizing rod. And a push-up pressurizing source mounted substantially at the center of the push-up member, and a support frame that supports the push-up pressurization source together with the push-up member so as to be movable up and down. The press A guide column attached to the push-up member so as to be positioned in parallel on both sides of the bevel pressure source, and a support plate for supporting the push-up pressurization source up and down with these guides, A spot welding apparatus characterized in that a lower end portion of the guide column is bridged by a connecting plate, and the support frame is framed in a square shape or a cubic shape.   The spot welding apparatus according to claim 1, wherein the support frame is formed in a box shape.   2. The spot welding apparatus according to claim 1, wherein the push-up member is composed of at least two layers of plate-like material, and an insulating layer is interposed between these plate-like materials.   The spot welding apparatus according to claim 1, wherein the insulating layer is a synthetic resin layer.   3. The spot welding apparatus according to claim 1, wherein a long guide bush is attached to the support plate, and the support support is guided up and down through the guide bush. 6. The spot welding apparatus according to claim 1, 2 or 5, wherein the guide bush is formed in a long shape corresponding to a length of 1/2 to 1/3 of the support column.

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