Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K11/00—Resistance welding; Severing by resistance heating
  • B23K11/30—Features relating to electrodes
  • B23K11/31—Electrode holders and actuating devices therefor

Definitions

• the present invention relates to a spot resistance welding machine. More specifically, for example, a work such as a metal box or a metal frame is placed on a lower electrode made of a conductive plate-like material such as a copper plate, and the lower electrode is placed on the lower electrode.
• This is a spot resistance welding machine that places the work piece between the upper and lower electrodes and presses and conducts electricity by directing the upper electrode toward the placed work piece.
• the present invention relates to a spot resistance welding machine capable of injecting a welding tip into a workpiece such as a metal box and welding while holding a welding gun having a welding tip at a tip in a horizontal position.
• a metal plate, a metal box or a metal frame to be welded (hereinafter referred to as a material to be welded or an object to be welded) is overlapped, and this portion is pressurized and energized.
• the method of joining by heating by using resistance heat as a heat source is called resistance welding method.
• the resistance welding method has been put to practical use as spot welding and seam welding and has been up to the present. That is, It is widely used in spot welding in general in the field of assembling metal bodies, as well as in the assembly line of automobile bodies and in the field of sheet metal processing.
• spot welding uses the Joule heat generated inside the material to be welded as a heat source, so the welding temperature depends on the welding current as well as the welding current. There is a drawback that it is not always constant, depending on the resistance value, etc., and this drawback has not been improved yet.
• spot welding does not require welding rods or flux unlike arc welding, and has the advantage of not necessarily requiring a large welding machine.
• the heating at the welded portion is limited to a point or a narrow area and is localized, the object to be welded is hardly damaged. For this reason, spot welding is widely used in the fields of automotive bodies, steel furniture and home appliances.
• spot welding has many advantages not found in other welding methods, and large dedicated automatic spot welding machines are now in practical use.
• most of these automatic spot welders are stationary spot welders, and the range of application to heavy objects such as metal boxes that are difficult to move for welding is limited. Improvements in this regard are desired, but little has been achieved.
• the principle of the spot welder is that two superposed workpieces Between the upper and lower electrodes, consisting of a pair of rod-shaped welding guns, from the top and bottom, so that the tip of each electrode, that is, the area that can be sandwiched by the welding tips attached to the opposite ends, in other words, spots or points Welding is carried out by applying pressure, and this is called spot welding. Therefore, the structure of the welding machine is such that the welding tips at the leading ends of the rod-shaped upper electrode and lower electrode are provided to oppose each other, and by lowering the upper electrode toward the lower electrode, the workpiece is locally pressurized. It is welded by energizing. For this reason, the upper and lower electrodes are usually provided integrally, and these lower electrodes are configured to be supported by a strong mechanical holding device.
• a stationary type is used by being installed in a fixed place because the upper and lower electrodes are fixed integrally with a mechanical holding device.
• This is a disadvantage of the stationary type and the workpiece is moved to the welding machine every time welding is performed.If the workpiece is a large-sized structure, it must be transported with heavy heavy work. It becomes.
• a portable type welding machine has been used instead of a stationary type spot welding machine.
• Portable type welding machine One or both of the electrodes are separated from the welding machine body, and a space between them is connected by a flexible conductive cable so that at least one of the upper and lower electrodes can be freely moved.
• the upper electrode is configured to be portable and can move freely, but for example, a pressurizing mechanism cannot be provided integrally with the upper electrode. For this reason, the welding pressure at the time of welding is limited, and a welded joint having a predetermined strength cannot be obtained.
• the upper electrode of the upper and lower electrodes is configured as a rod-shaped welding gun having a welding tip at the tip, but the lower electrode is configured of a plate-shaped electrode made of a plate-shaped conductive material. Is what you do.
• any part of the surface of the lower electrode can serve as a current-carrying part. Therefore, if the upper electrode is moved according to the welding point of the workpiece placed on the lower electrode, welding can be performed without moving the workpiece.
• the moving upper electrode is configured as a rod-shaped horizontal gun held in a horizontal posture, and is rotatably supported at a midpoint of the horizontal gun through a support bost.
• This spot welding machine applies an upward pulling force to the rear end of the horizontal welding gun at the upper electrode, and uses the downward rotating moment acting on the welding tip at the tip as the pressing force during welding. Therefore, the welding tip at the tip of the welding gun in the upper electrode can penetrate the inside of the workpiece, such as a box, and the welded point hidden inside can be welded by applying pressure and current.
• the welding pressure during welding is the rotational moment of the upward pulling force acting on the welding tip at the tip of the horizontal welding gun at the upper electrode, and its value depends on the length of the horizontal welding gun at the upper electrode. Is done.
• a support boss that rotatably supports the horizontal welding gun is required.
• a plane moving mechanism that freely moves the support boss on a plane is required.
• the structure and use of the plane moving mechanism are repeated. Deterioration of the structure affects the positioning accuracy of the welding tip at the welding gun tip.
• spot welding itself uses a heat source whose temperature is not known by nature, and the welding temperature is essentially not controlled precisely.
• Support post and its plane moving mechanism especially Unless the plane moving mechanism has been structurally improved enough to withstand high welding pressure, air cylinders, and other heavy supporting loads, welding cannot be performed under high pressure with high positioning accuracy. There is. However, no improvement has been observed in this regard.
• spot welding is a welding method that uses a heat source whose temperature is not known, but this point can be modified to some extent by the selection of matching welding jigs and tools, and the so-called craftsmanship and experience.
• the support structure for the horizontal welding gun and the horizontal movement mechanism such as the horizontal welding gun, the supporting arms that support them are configured by connecting at least two split arms, and each split arm is rotated. It is configured to be able to turn with a free rotating shaft. For this reason, the rotating shaft will be loosened or damaged after repeated use. No improvement has been made in light of this.
• a pressurizing device such as a air cylinder is provided integrally with the upper electrode along with the welding gun.
• the upper electrode is a hair cylinder that applies pressure to the horizontal welding gun.
• the upper electrode having such a structure is integrally provided, and is integrally supported on the lower electrode so as to be movable in a plane direction. For this reason, the upper electrode is supported like a so-called cantilever at the tip or free end of the support arm, but this support arm is configured by connecting at least two split arms via a rotating shaft. ing.
• At least one split arm of the support arm that supports the upper electrode expands and contracts by rotating at least one split arm at the rotation axis, and thus the upper electrode is moved.
• the welding tip of the horizontal welding gun is positioned at a predetermined position and welded.
• the support arm has a zigzag plane shape as a whole, resulting in increased torsion.
• the air-cylinder momentarily applies a downward pressure, which causes a large bending moment and other torsional moments. In particular, it is applied to the joint of the split arms, that is, the rotating shaft to be joined.
• the present invention includes a lower electrode made of a flat conductive plate-like material, and an upper electrode that is to be welded and placed on the lower electrode and that is pressurized and energized by resistance current welding between the lower electrode. It is a spot resistance welding machine.
• a welding tip that is mounted as a part of the upper electrode and conducts resistance welding by applying a downward pressure to the work to be welded, and is disposed substantially horizontally on the lower electrode to support the upper electrode at the free end;
• a supporting arm that can be freely expanded and contracted or folded; at least two divided arms provided as a part of the supporting arm and having opposing ends connected to each other; and opposing each other between two adjacent divided arms among these divided arms And a coupling device for coupling the opposed ends.
• This coupling device also has one of the two adjacent split arms A cylindrical support attached to the opposite end of the split arm; a fixed shaft inserted into the cylindrical support and attached to the opposite end of the other split arm; and a cylindrical mounted around the fixed shaft.
• a conical bearing is provided for rotatably supporting one of the split arms via a support body.
• a horizontal welding gun used in a horizontal position is provided as a part of the upper electrode, and a shank tube having a welding tip at the tip and a gun body into which the shank tube is freely inserted.
• the upper electrode is provided with an air cylinder that pulls upward at the rear end of the gun body in the horizontal welding gun.
• the rear end of the gun body is configured to rotate freely.
• FIG. 1 is an explanatory diagram of a welding mechanism in a spot welding machine according to one embodiment of the present invention.
• FIG. 2 is a plan view of a spot welding machine according to one embodiment of the present invention when viewed from above.
• FIG. 3 is a side view when viewed from one side of the welding machine shown in FIG.
• FIG. 4 is a partial sectional view of an example of a lower electrode of the welding machine shown in FIG.
• FIG. 5 is an assembly view of the split arm in the spot welding machine shown in FIGS. 2 and 3.
• FIG. 6 is a sectional view of a part of the split arm shown in FIG.
• FIG. 7 is a side view of the horizontal welding gun provided as a part of the upper electrode.
• FIG. 1 shows, as a diagram, the welding mechanism of the spot welding machine according to the preferred embodiment of the present invention.
• This welding mechanism is equivalent to the welding mechanism of the spot welding machine previously proposed by the present inventors, and the present invention is not new here.
• the present invention is a spot welding machine that performs spot welding by a welding mechanism equivalent to that shown in FIG. 1, and the feature of the spot welding machine is that the spot welding can be performed stably. even those requiring high pressure, such as Aruminiumu material or stainless steel to provide a spot welding machine having a structure capable spot welding with stable (Therefore, the structure of the place below Will be described.
• reference numeral 100 generally indicates a spot welding machine.
• reference numeral 1 is the welding machine main body
• 2 is a transformer
• 3 is an electronic switch such as a thyristor contact
• 4 is an electronic switch of two thyristors 4
• 5 Indicates a power source
• 6 indicates an emergency.
• Steel plate, aluminum for welding machine body 1 It can spot-weld workpieces W such as sheets, stainless steel sheets, and other metal sheets, and can stably weld aluminum sheets and stainless steel sheets that require high pressure.
• the welding machine body 1 is provided with a lower electrode 10 and an upper electrode 20 facing each other, and the lower electrode 10 is provided with a plate electrode 11 made of a flat conductive plate material.
• the workpiece W is placed on the electrode 11 and the workpiece W can be welded to a desired welding point without moving.
• the work W to be welded placed on the plate electrode 11 of the lower electrode 10 is: Pressing is performed by lowering the welding tip 22 at the top end of the horizontal welding gun 21 in the upper electrode 20 to perform spot welding.
• the lower and upper electrodes 10 and 20 are connected to respective poles of the transformer 2, and the current from the welding power source 5 is rectified by the electronic switch 4 and the voltage is adjusted by the transformer 2. Then, it is supplied to the lower and upper electrodes 10 and 20.
• the lower electrode 10 is provided with a plate-like electrode 11 made of a conductive plate-like material having a flat surface, and the workpiece W (FIGS. 1 and 2) is provided on the plate-like electrode 11. 2), and the specified work can be performed on the workpiece W as it is.
• This plate-like electrode 11 constitutes an electrode over the entire surface, and the upper electrode 2
• the part pressurized by the welding tip 22 of the horizontal welding gun 21 at 0 acts as a welding tip for spot welding.
• any part of the surface of the plate electrode 11 functions as an electrode, and the workpiece W can be welded without moving.
• copper or an alloy thereof is used as the conductive plate-like material, which is connected to one pole of the transformer 2 and is ignited at a desired welding point on the workpiece W, that is, a nugget. Can be formed.
• a rod-shaped welding gun 21 is attached to the upper electrode 20 so that the welding gun 21 can be welded in a lateral position, as shown later, and a welding tip 22 at the tip is attached.
• the welding tip 22 is connected to the other pole of the transformer 2, and heat is conducted between the plate electrode 11 connected to one of the poles with the workpiece W interposed therebetween to perform spot welding. Is done.
• the object to be welded W on the plate electrode 11 is the welding tip of the upper electrode 20.
• the welding current is conducted where the pressure is applied by 2 to form an electrode.
• the welding on the plate electrode 11 is performed. Only the contact part of the object W becomes an electrode and is spot welded. That is, the plate-like electrode on the lower electrode 10 At the pole 11, the workpiece W is sandwiched between the contact portion with the workpiece W and the tip of the welding gun 21 at the upper electrode 20, that is, the welding tip 22. The sandwiched part is resistance-heated and pressure welded.
• the welding gun 21 is mounted in a horizontal position as a part of the upper electrode 20 while the welding gun 21 is mounted on the lower electrode 10.
• At least two split arms 31, 32, 33 that are connected to each other by a connecting device 40 between opposing ends as a plane moving mechanism in order to move the plane horizontally in a horizontal direction while maintaining substantially horizontal.
• a support arm 30 is provided, and the top end of the support arm 30 supports the upper electrode 20 and at least the horizontal welding gun 21.
• the support arm 30 is composed of at least two divided arms 31, 32, 33 as shown in FIGS. 2 and 3, and connected by the connecting device 40 therebetween. In the coupling device 40, as shown in FIGS.
• a cylindrical support body 41 is attached to the opposite end of one of the two adjacent divided arms 31 and 32.
• a fixed shaft 42 is attached to the opposite end of the other split arm 32.
• the fixed shaft 42 is inserted into the cylindrical bearing 41, and a conical bearing 43 is disposed around the fixed shaft 42, and the cylindrical bearing 4 rotating via the conical bearing 43. 1 is configured so that one of the split arms 31 is turned.
• a conical bearing 43 is fixed around the fixed shaft 42 and the pressing member 44. It is divided into upper and lower parts.
• the holding member 44 is pressed from above without directly contacting the fixed shaft 42, for example, its shoulder portion 421. In this case, it is kept with a small gap G.
• the holding member 44 is pressed down in this manner, when the holding member 44 is pressed down, the conical bearing 43 disposed above is first pressed, and the rolling of the conical bearing 43 is smoothed.
• the lower conical bearing 43 is also pushed and the rolling thereof can be smoothed.
• the upper and lower cone bearing groups are adjusted separately because the load imposed on the fixed shaft 42 differs in the axial direction, and the load imposed on the upper Because it is big.
• the connecting device 40 is further described.
• the connecting device 40 connects two adjacent divided arms 31 and 32 to each other and forms a part of the support arm 30.
• This area is subject to repeated stresses such as shearing, bending, torsion, tension, and compression. That is, the load on the air cylinder and other upper electrodes is applied downward, and during welding, a high pressing force is applied upward by pulling upward on the air cylinder and other parts. The stress resulting from this is applied repeatedly. For this reason, the connecting device 40 and its components are deflected, and the components are loosely assembled, making it difficult to accurately position the welding gun 21 in the upper electrode 20. In addition, repeated use can damage the components in just one to two years.
• the shafts serving as the rotation centers of the divided arms 31 1, 32, and 33 constituting the support arm 30 are fixed, and can be rotated around the fixed shaft.
• the configuration is as follows. 'For example, in the adjacent divided arms 3 1 and 3 2, a fixed shaft 42 is fixed to the opposite end of the other divided arm 32, and one of the divided arms 31 is centered on the fixed shaft 42. It is configured to be rotatable via a cylindrical support body 41 attached to the base. Further, the fixed shaft 42 can be fixed in any mode, but as shown in FIG. 6, can be fixed from above and below by using fixed plates 45 and 46.
• the fixed shaft 4 2 is fixed to the upper fixed plate 4 5
• a so-called knuckle 47 can be used, and if it is fixed in this manner, it can be locked without loosening while leaving the gap G.
• the member 44 can be configured so that it can be adjusted by pushing down. That is, as shown in FIGS. 5 and 6, the holding member 44 is formed as a stepped cylindrical body, through which the upper part of the fixed shaft 42 penetrates.
• the holding member 44 is integrally formed by being fixed to the fixed shaft 42 with a key or the like, and this serves as a central axis when the divided arms 31, 32, and 33 rotate; As if the center shaft had a split structure, the holding member 4 4 and the fixed shaft 42 could be supported by conical bearings 4 3, respectively, avoiding the effects of various loads and stresses applied to the coupling device 40. it can.
• one of the split arms 31 is provided with a turning adjustment member 50 (see FIG. 5).
• the fixing plate 45 on the other split arm 32 side is brought into contact with 0.
• the other arm 32 is rotated with respect to one arm 31, and the support arm 30 is extended and contracted according to the degree of the rotation.
• the electrode 20 is moved in a plane.
• the axes of the divided arms 31, 32, 33 are aligned with one straight line, and extend straight to the support arm 30. Even if a force is applied to the extended arm 31, 32, 33 from the axial direction, the arm 31, 31, 32, 33 cannot rotate at all. If the angle between the adjacent divided arms 31 and 32 becomes zero as described above, it becomes difficult to rotate one of the divided arms 31 with respect to the other of the adjacent divided arms 32.
• the pivotal adjustment is performed on one split arm 31. Since the material 50 is provided, such a problem does not occur and can be reliably avoided.
• the plate-like electrode 11 provided as a part of the lower electrode 10 is made of a flat conductive material made of copper or an alloy thereof, and the plate-like lower electrode 10 has the material W to be welded thereon. It is configured so that work such as predetermined processing can be performed after the work is completed.
• the surface of the lower electrode 10 is configured as a flat plate-like electrode 11 and configured to withstand a high pressing force during welding. For this reason, for example, it is configured as a lattice or rod-shaped frame, and the plate-like electrode 11 is provided on the surface. I can.
• an insulating material 12 is interposed, and the plate-like electrode 11 is transformed on the other hand through, for example, a conductive terminal 13 in the form of a screw. It is connected to one pole of the container 2, and the periphery of the conductive terminal 13 is surrounded and insulated by the tubular member 14 made of insulating material and the washer 15.
• the horizontal welding gun 21 is configured to apply a pressing force to the welding tip 22 at the distal end through an air cylinder 60 or the like using a lever mechanism. That is, as shown in FIG. 7, a welding tip 22 is attached to the tip of the shank tube 24, which is composed of a gun body 23 and a shank tube 24.
• the upper electrode 20 including the welding gun 21 and the air cylinder 60 is supported by the column 70 via the support arm 30.
• the upper electrode 20 is provided with a welding gun 21, a support boss 80 that rotatably supports the welding gun 21, and an air cylinder 60 that is supported by the support boss 80. .
• each of the divided arms 31, 32, and 33 is turned through the connecting device 40, and the support arm 30 is freely extended and contracted, and the welding is performed.
• the gun 21 freely moves in a plane together with the air cylinder 60 to position the welding chip 22 at a predetermined welding point.
• the gun body 23 and the shank tube 24 are configured to be able to be pulled out freely, and the welding tip is also provided at the tip of the shank tube 24.
• 22 is detachably mounted, and a water cooling passage is formed along the central axis as required.
• a handle 25 is attached to the rear end of the gun body 23 as required, while the tip of the gun body 23 is rotated about the rotation axis 82 of the bent portion 81 at the lower end of the support bost 80.
• the support bost 80 is formed in a hollow tube shape, through which a tension member such as a wire is inserted, the lower end of the tension member is connected to the rear end of the gun body 23, and the upper end is a hair cylinder. Connect to 60.
• the welding gun 21 itself is a lever mechanism with the rotating shaft 82 as a fulcrum.
• the upward tensile force provided by the arc cylinder 60 is transmitted to the welding tip 22 at the tip as a rotational moment.
• the welding tip 22 can penetrate into the portion to be welded, pressure welding can be performed even on the portion to be welded that is hidden inside.
• the applied pressure is this rotational moment, it can be adjusted by adjusting the length of the freely removable shank tube 24, and the adjustment is extremely easy.
• the welding tip 22 can be moved up and down by operating the handle 25. Even if an obstacle protrudes inside the workpiece W such as a frame or box, it can be overcome.
• the upper electrode 20 has been described mainly on the case where the welding gun 21 is used in the horizontal position.However, the welding gun can also be used in the vertical position. It is sufficient to configure the robot so that it can be raised and lowered directly.
• a work to be welded such as a metal box or a metal frame is placed on a lower electrode made of a conductive plate-like material such as a copper plate, and the work to be welded placed on the lower electrode
• a work to be welded is placed on a lower electrode made of a conductive plate-like material such as a copper plate, and the work to be welded placed on the lower electrode
• the upper electrode By directing the upper electrode toward the object, the object to be welded is sandwiched between the upper and lower electrodes, and pressurized electricity is applied to the spot to be welded. This is a resistance welding machine.
• the welding gun having the welding tip at the top end of the upper electrode can be freely moved in a plane while holding the welding gun in the horizontal position, and the welding tip can be penetrated to the inside of the workpiece such as the metal box to perform welding.
• the welding gun mounted as part of the upper electrode is supported by the free end of a freely expandable or contractible support arm, which is composed of at least two split arms whose opposite ends are connected to each other, The opposing ends of two adjacent split arms of these split arms are connected by a connecting device, and the connecting device further includes opposing ends of one of the two adjacent split arms.

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• Mechanical Engineering (AREA)
• Resistance Welding (AREA)

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Citations (3)

• 2002
  • 2002-06-28 JP JP2002191400A patent/JP2004034049A/ja active Pending
• 2003
  • 2003-06-30 WO PCT/JP2003/008292 patent/WO2004002667A1/ja not_active Ceased

Patent Citations (3)

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