JP4348745B2 - Spot resistance welding machine - Google Patents

Description

  The present invention relates to a spot resistance welder.

A conventional spot resistance welding machine of this type sandwiches a lower electrode having a plate-like electrode made of a flat conductive plate-like material on the surface and an object to be welded placed on the plate-like electrode on the lower electrode. And an upper electrode that is resistance-welded by applying pressure and a support arm that supports the upper electrode at the free end, and the support arm is composed of at least two divided arms. -The power is supplied to the upper electrode from the power supply unit via the bearings at the opposite ends, and the power supply to the upper electrode is generally supplied to the upper electrode, the support arm, and the installation column that supports this support arm. It was performed by the conductive cable wired along (for example, patent document 1).
JP 2005-74459 A

  In the prior art, the upper electrode is usually free, and the operator manually moves the upper electrode to the respective welding points on the lower table-like lower electrode, lowers the upper electrode and welds it. A water-cooled or air-cooled crimped cable wire suitable for the welding current is placed along the arm. It has become.

  In addition, an arm with a plurality of joints is usually made of iron, but the position of the secondary cable slightly affects the welding result. For example, if an iron plate or a structure is inserted between the lower electrode and the upper electrode cable wire, it is affected by the magnetic action during energization, and the current flowing through the actual weldment decreases, which may cause power loss. Is done.

  That is, when a magnetic material such as iron is placed in a space sandwiched between secondary conductors of an AC resistance welder, the welding current (current flowing through the secondary conductor) decreases. This is caused by iron loss generated in a ferromagnetic material such as iron. As the cause element (1), there is hysteresis loss. This is because when a current flows through the secondary conductor, a line of magnetic force is generated and a magnetic field (magnetizing force) is generated. When the magnetizing force generated in a ferromagnetic body placed in the magnetic field increases or decreases, the molecular magnets in the magnetic body are arranged accordingly. However, because there is friction between the molecular magnets, they cannot be arranged freely, causing a hysteresis phenomenon, and heat is generated due to friction between the molecular magnets, resulting in loss. Magnetic hysteresis is a phenomenon in which the magnetic history of a ferromagnetic such as iron affects the subsequent magnetization state.

  Furthermore, in a general spot resistance welder, the arm of a spot welder in which the upper electrode freely travels forward, backward, left and right with a plurality of joints is guided by the operator to a predetermined position during work. However, if the work piece is to be replaced or moved away from the arm for other purposes, the evacuation installation location is usually determined in advance and guided to that position by hand. Fix it so that it cannot move. In actual work, it is easier to enter the next work immediately next to the weldment, and workability improves if there is no problem in replacement, and more than anything, there are various degrees of freedom that can be fixed at any place. Create a good working environment that is responsive to things. For this purpose, non-excitation electromagnetic brakes are attached to a plurality of joints. During the work, the brake coil is energized to release the brake, and when the work is completed or when it is necessary to release the hand, the excitation is released and the arm is braked and stopped.

  In addition, a general table type spot resistance welding machine is a plate-shaped or flat plate-shaped plate placed on a copper or copper alloy table with good electrical conductivity and welded on it. An upper electrode with a plurality of joints that can be moved freely forward, backward, left, and right is placed on a workpiece or workpiece, and the upper electrode using an air cylinder or the like is lowered and welded at the welding point. is there.

  However, spot welding power sources have also made remarkable progress in recent years, and there are some that can be welded even if the lower workpiece is not in close contact with the lower electrode. For example, pipes, the upper surface of cylindrical workpieces, etc. It is impossible to weld unless the lower electrode is inserted into the tube and attached to the inside of the tube, but the upper electrode can be lowered and welded with the plate or work piece to be welded to the upper surface of the pipe while it is placed on the table. became.

  In addition, even with a conventional welding power source, it is of course possible to manufacture copper or a copper alloy with good electrical conductivity on the lower table electrode according to the welded material and set it on the table for welding. In fact it is possible. In order to perform these operations, the range in which welding is possible is limited by the descending height and stroke of the upper electrode.

  The problem to be solved is to prevent power loss and reduce fatigue of workers due to heavy crimped cable wires.

The invention according to claim 1, a lower electrode, an upper electrode of the object to be welded by energizing Nde clamping resistance welding to the lower electrode, a support post mounted the upper electrode, for supporting the support post at the tip support Arm and
The support arm comprises at least two split arms, which are pivotally connected at their opposite ends,
One of the divided support arms is formed integrally with a conductive member formed of copper or a copper alloy for energization of welding by superimposing a ferrous metal such as steel along the base end from the front end. The split support arm is formed integrally with a conductive member formed of copper or a copper alloy for energization of welding by superimposing an iron-based metal such as steel along the base end from one end thereof. An electrical connection portion that connects the conductive member of the support arm and the conductive member of the other divided support arm is provided at the opposed end, and the electrical connection portion has one conductive member side as a rotating electrode, The spot resistance welding machine is characterized in that the conductive member side is formed by a power supply brush.

  According to the first aspect of the present invention, it is possible to prevent power loss by energizing the conductive member for welding, and to reduce worker fatigue caused by heavy crimped cable wires. In addition, a conductive member can be incorporated into a part of the divided support arm by superimposing a high-strength metal on a highly conductive conductive member for welding energization.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all the configurations described below are not necessarily essential requirements of the present invention.

The figure shows a reference example, and a spot welder is provided with a lower electrode 1 arranged at the lower portion facing each other and an upper electrode 2 provided on the upper portion of the lower electrode 1, and in spot welding, there is a gap between them. welded object (workpiece) W is sandwiched rare pressure energized. The lower electrode 1 is provided with a plate-like electrode made of a flat conductive plate-like material on the surface, and the workpiece W is placed on the plate-like electrode having a table shape. Then, the workpiece W is placed without being moved at the time of welding, the welding gun 3 is moved to the desired welding point as the upper electrode 2, and the welding tip 4, also referred to simply as the tip, is positioned to be welded. The object W can be pressurized and spot-welded. A primary electric cable 5A is connected to the welding power source 5, and the lower electrode 1 and the welding gun 3 are electrically connected to the welding power source 5 so that a current from the welding power source 5 is supplied. Yes.

  In the horizontal primary support arm 7 in which the distal end 7A is connected to the upper part 6A of the support post 6 that supports the welding gun 3 in the lower part so as to be horizontally rotatable, the base end 7B is fixed directly or indirectly on the floor. It is connected to the upper portion 8A of the installation column 8 that supports the welding gun 3, the support arm 7, and the like so as to be horizontally rotatable.

  The upper 6A side of the support post 6 and the distal end 7A side of the support arm 7 are pivotally connected to each other via first bearings 10 at first opposing end portions 9 respectively. The first bearing 10 is attached to the tip 7A of the support arm 7 via an insulating material 10A such as bakelite or Delrin resin (registered trademark) which is polyacetal resin (POM). Further, the base end 7B side of the support arm 7 and the upper portion 8A side of the installation column 8 are connected to each other at the second opposing end portions 11 via the second bearings 12 so as to be freely rotatable. The second bearing 12 is attached to the base end 7B of the support arm 7 via an insulating material 12A such as bakelite or delrin resin. Further, the support arm 7 includes two first divided arms 13 and a second divided arm 14, and the first divided arm 13 and the second divided arm 14 are connected to each other at the third opposing end 15. The third bearing 16 is pivotably connected. The third bearing 16 is attached to the tip 14A of the second split arm 14 via an insulating material 16A such as bakelite or Delrin resin.

  The installation column 8 can be moved up and down with respect to a fixed base 17 fixed to the floor. For this purpose, a guide member 18 is erected on the fixed base 17 so that the installation column 8 can be moved vertically. In addition, an elevating drive means 19 for the installation column 8 is provided on the fixed base 17 so as to move up and down along the guide member 18. The elevating drive means 19 is configured such that a rotating shaft 21A of a motor 21 is directly or indirectly connected to a screw shaft 20 erected along the guide member 18 so that the screw shaft 20 can be rotated forward and backward by the motor 21. On the other hand, a female screw member 22 that is screwed into the screw shaft 20 is provided on the installation column 8 side. By rotating the screw shaft 20 forward and reverse by the motor 21, the installation column 8 is female. The screw member 22 can be raised and lowered. In the figure, reference numeral 21B denotes a rotation transmission mechanism such as a worm / worm wheel for converting the rotational shaft 21A from the horizontal direction into the vertical screw shaft 20, and 21C denotes the lower portion 8B of the installation column 8 and the guide member. 18 is a sliding member interposed between the two. The elevating drive means 19 may be formed by a cylinder device using air pressure or hydraulic pressure, or a manual link mechanism.

  The upper electrode 2 is attached to the lower portion 6B of the vertical support post 6. The welding tip 4 is held at the lower end of a conductive holder 23, and this holder 23 is detachably fixed to a secondary support arm 24 provided laterally on the lower portion 6B of the support post 6.

  At least a part of the support post 6 is formed from an upper part 6A to a lower part 6B by a conductive member, specifically, copper or a copper alloy which is a highly conductive member. In the embodiment, the entire support post 6 is integrally formed of a highly conductive member. Further, the support arm 7 is formed at least partly from the distal end 7A to the proximal end 7B by a conductive member, specifically, copper or copper alloy which is a highly conductive member. In the embodiment, at least a part of the first divided arm 13 from the distal end 7A to the proximal end 13B and from the distal end 14A to the proximal end 7B of the second divided arm 14 is electrically conductive. The conductive member is formed of copper or a copper alloy. In the embodiment, the entire first divided arm 13 on the distal end 7A side and the second divided arm 14 on the proximal end 7B side are integrally formed by a highly conductive member. Further, the lower portion 8B of the installation support column 8 is formed of, for example, a cylindrical member having a square shape, and an upper portion 8A is provided on the upper surface of the lower portion 8B via an insulating material 8C such as bakelite. At least a part is formed along the vertical direction with a conductive member, specifically, copper or a copper alloy which is a highly conductive member. In the embodiment, the entire upper portion 8A of the installation column 8 is integrally formed of a highly conductive member, and the secondary electric cable 5B from the welding power source 5 is connected to the lower side of the upper portion 8A itself.

  In the embodiment, at least a part of the support post 6, the first divided arm 13, the second divided arm 14, and the upper portion 8 </ b> A of the installation column 8 is formed of a conductive member such as copper or copper alloy. Is a structure in which a conductive member is incorporated in a part of the structure such as the support post 6 and the first split arm 13 instead of an electric cable. A ferrous metal such as high strength steel is integrally formed on a conductive member such as copper or copper alloy.

  Further, the lower portion of the support post 6 and the conductive portion 24 </ b> A called a shank of the support arm 24 are connected via a bracket 25 by a power supply cable 26.

  In the first opposing end 9, a first rotating electrode 27 is formed in a coaxial cylindrical shape by a conductive member on the upper portion 6 </ b> A of the support post 6, and the first rotating electrode 27 is rotatably fitted on the first rotating electrode 27. A first bearing 10 is provided. The first bearing 10 is connected to the tip 7A of the support arm 7, that is, the tip 7A of the first split arm 13. A first power supply brush 28 that is an electric brush is slidably in contact with the first rotating electrode 27, and the first power supply brush 28 is fixed to the tip 7 </ b> A of the first split arm 13. In addition, the distal end side 7A of the first split arm 13 and the first rotating electrode 27 side are electrically connected by a first power cable 30 via a first bracket 29. The first electrical connection portion 31 is formed by the first rotating electrode 27 and the first power supply brush 28.

  In the second opposing end portion 11, a second rotating electrode 32 is formed in a coaxial cylindrical shape by a conductive member on the upper portion 8 </ b> A of the installation column 8, and is rotatably fitted to the second rotating electrode 32. A second bearing 12 is provided, and the second bearing 12 is connected to the base end 7B of the support arm 7, that is, the base end 7B of the second split arm 14. The second power supply brush 33 is slidably in contact with the second rotating electrode 32, and the second power supply brush 33 is fixed to the base end 7B of the second split arm 14, The base end side 7B of the second split arm 14 and the second rotating electrode 32 side are electrically connected by a second power cable 35 via a second bracket 34. A second electrical connection portion 36 is formed by the second rotating electrode 32 and the second power supply brush 33.

  Further, an upper shaft portion 37 for the installation column is projected upward on the second rotating electrode 32, and a spring (not shown) for installation column is provided on the second split arm 14 side, for example, when power is turned off or power is cut off. ) Is provided with a spring-closed non-excitation actuating electromagnetic brake 38 (non-excitation actuating (negative actuating) electromagnetic brake) in which a braking force is applied. The non-excitation electromagnetic brake 38 is connected to a control device 39 to which a welding power source 5 is also connected. The brake is activated when no power is supplied, and the upper shaft portion 37 for the installation column, and thus the upper portion 8A is connected to the lower portion 8B. Thus, the direction of rotation can be fixed, while the brake is released when energized.

  In the third opposed end portion 15, a third rotating electrode 40 is formed in a coaxial cylindrical shape by a conductive member on the upper portion of the base end 13 B of the first split arm 13. A third bearing 16 is provided that is rotatably fitted outside, and this third bearing 16 is connected to the tip 14A of the second split arm 14. The third power supply brush 41 is slidably in contact with the third rotating electrode 40. The third power supply brush 41 is fixed to the tip 14A of the second split arm 14, and the The base end 13B side of the one split arm 13 and the tip end 14A of the second split arm 14 are electrically connected by a third power cable 43 via a third bracket 42. A third electrical connection portion 44 is formed by the third rotating electrode 40 and the third power supply brush 41.

  Further, a split arm upper shaft portion 45 is projected upward from the third rotating electrode 40, while the split arm non-excitation actuating electromagnetic brake 46 (non-excitation) is provided on the second split arm 14 side. (Operating (negative operating) electromagnetic brake) is provided. In addition, an electromagnetic brake is provided in the location of the 1st opposing edge part 9 as needed. The embodiment shows a case where no electromagnetic brake is provided.

  Next, the operation of the above configuration will be described. When the control device 39 is turned on, power is supplied to the welding power source 5, and further, power is supplied to the installation column non-excitation electromagnetic brake 38 and the split arm non-excitation electromagnetic brake 46. These brakes are released by supplying power to the non-excited electromagnetic brake 38 for the installation column and the non-excited electromagnetic brake 46 for the split arm.

  Next, with the workpiece W placed on the lower electrode 1 in advance, the operator drives the motor 21 to rotate the screw shaft 20 to move the installation column 8 together with the support arm 7 up and down. The upper electrode 2 side is adjusted to a height suitable for work. Next, by holding the welding gun 3 which is a free end and moving it freely through the first bearing 10, the second bearing 12 and the third bearing 16, the welding tip 4 can be moved. Welding is performed by hitting a predetermined portion of the work piece W. At this time, the power supply from the welding power source 5 is supplied from the secondary electric cable 5B to the upper portion 8A, the second rotating electrode 32, the second power supply brush 33, the second power supply brush 33, as shown by the electric flow E shown by the two-dot chain line. The second divided arm 14 is reached via the second bracket 34 and the second power cable 35, and the third power cable 43, the third bracket 42, the third bracket 14 are provided from the tip 14A of the second divided arm 14 itself. To the first split arm 13 via the power supply brush 41 and the third rotating electrode 40, and further from the tip 7A of the first split arm 13 itself to the first power cable 30, the first bracket 29, the first To the conductive portion 24A of the secondary support arm 24 through the power supply brush 28, the first rotating electrode 27, the support post 6, the power supply cable 26, the bracket 25, and the like, and from the conductive portion 24A to the holder 23 and the welding tip 4 Is supplied with power. In this way, spot welding is performed. The voltage of the flow E is set relatively low.

  On the other hand, when the power source of the control device 39 is turned off, the welding power source 5 is cut off, and the non-excitation electromagnetic brake for the installation column 38 and the non-excitation electromagnetic brake for the split arm 46 are also cut off. Then, when the non-excited electromagnetic brake 38 for the installation column and the non-excited electromagnetic brake 46 for the split arm are de-energized, the brake is activated, and the second split arm 14 and the first split arm 13 are locked. Never move. Further, even when a power failure occurs due to an earthquake or fire during operation, the second split arm 14 and the first split arm 13 are locked by power interruption or by an earthquake detection means (not shown).

As described above , the feeding brushes 28, 33, 41 are in contact with the rotating electrodes 27, 32, 40 to energize the upper electrode 2, and the copper body having a sufficient cross-sectional area is delivered to the final welding tip 4. Can do.

  It also has a simple appearance, good workability, and power saving.

  Furthermore, there is a phenomenon that the secondary conductor cable wire usually reacts in response to the current during welding, but since the entire arm serving as the fuselage is a conductor, there is no need for the reaction to occur and the welding point to be staggered. And it can be set as the structure which connects with a conductor with flexibility everywhere, and absorbs a reaction.

  Further, in a spot welder, a non-excitation electromagnetic brake 38 for an installation column and a non-excitation electromagnetic brake 46 for a split arm are provided, and the upper electrode 2 has a plurality of joints so that it can freely move forward, backward, left and right. It can be stopped and maintained everywhere, regardless of the lift, by applying brakes to these joints arbitrarily for welding work or for replacing the workpiece W to be replaced.

  Further, in a spot welder, one electrode (generally corresponding to the lower part) is a flat table, and the upper electrode 2 is an arm that can move back and forth and right and left with a plurality of joints. It is an upper / lower height adjustment device for the upper electrode 2 that allows the height of the upper arm to be adjusted by installing a lifting / lowering drive means 19 such as a motor 21 type or a jack having an up / down function such as an air cylinder at the beginning. According to the height of the work piece W on the electrode 1 (table), the support pole of the mounting position of the laterally moving upper arm is a motor 21 or an air cylinder so that the upper electrode 2 can be raised or lowered to the original position. Since it can be moved up and down to an arbitrary position with the lifting drive device, the work can be done in each case without considering the position (height) to be welded W in advance. The pipe, the best system for welding cylindrical workpiece.

  As described above, the spot resistance welder according to the present invention can be applied to various applications. The support arm may be formed by three or more split arms.

It is a front view showing the present invention. It is a top view which shows this invention. It is a front view around the installation column showing the present invention. It is sectional drawing around the upper part of the installation support | pillar which shows this invention. It is sectional drawing around the 3rd opposing edge part which shows this invention. It is a front view around a welding gun showing the present invention.

1 Lower electrode 2 Upper electrode 6 Support post 7 Support arm 8 Installation support
13 First split arm
14 Second split arm
15 Third opposing end
16 Third bearing
40 Third rotating electrode
41 Third power supply brush
44 Third electrical connection part W Workpiece

Claims (1)

And a beam, - a lower electrode, an upper electrode of the object to be welded by energizing Nde clamping resistance welding to the lower electrode, a support post mounted the upper electrode, the support A for supporting the support post at the distal end
The support arm comprises at least two split arms, which are pivotally connected at their opposite ends,
One of the divided support arms is formed integrally with a conductive member formed of copper or a copper alloy for energization of welding by superimposing a ferrous metal such as steel along the base end from the front end. The split support arm is formed integrally with a conductive member formed of copper or a copper alloy for energization of welding by superimposing an iron-based metal such as steel along the base end from one end thereof. An electrical connection portion that connects the conductive member of the support arm and the conductive member of the other divided support arm is provided at the opposed end, and the electrical connection portion has one conductive member side as a rotating electrode, A spot resistance welding machine, wherein the conductive member side is formed by a power supply brush.

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